Annotated Bibliography on The Evolution of Cooperation

Introduction

This guide includes work that makes use of Robert Axelrod's The Evolution of Cooperation (NY: Basic Books, 1984) or earlier work included in that book, such as the biological article by Robert Axelrod and William Hamilton of the same title in Science, vol. 211 (1981): 1390-96. While most of the items included in this bibliography explicitly cite this work, other research which draws heavily on the ideas and themes of Axelrod's approach is also cited here. This bibliography generally excludes work that makes only passing or minor reference to Axelrod.

We apologize to authors whose contributions we may have overlooked.

• PD: (iterated) Prisoner's Dilemma
• TFT: Tit-for-Tat
• ESS: Evolutionary (or Evolutionarily) Stable Strategy

This project was supported by the University of Michigan LSA College Enrichment Fund.

Keywords

• Assumptions and Concepts:
• Choices (if choices other than the two choices of cooperate or defect)
• Endogenous ending
  • voluntary exit (players may choose to exit the game)
  • ostracism
• Interactions (if greater than two players)
• Limited set of allowable rules
  • enumerated set (the work considers specific defined strategies such as TFT)
  • finite state machines (automata)
  • limited rationality
  • parameterized rules (allowable rules are specified by particular parameters)
• Noise
  • misimplementation (when the player makes a mistake implementing its choice)
  • misperception (when one player misperceives the other player's signal or choice)
• Norms
• Payoffs (also used when the work compares PD to other games)
• comparing PD matrices (used when the work compares different forms or versions of the PD)
• Population dynamics
• ESS
  • replicator dynamics (involving changing proportions of rules based on their success)
  • population size (distinguished from Interactions in that relations among players are bilateral, or population size is an independent factor)
• Population structure (non-random interactions)
  • information requirements (interact with others based on observable characteristics or signals)
  • clustering (tendency to interact with own type)
  • spatial models (local interactions or interactions with neighbors)
• Relative vs. absolute gains
• Reputation

Applications:

• Automata theory (including computer science)
• Biological applications
• Politics and Law, Domestic
• Politics and Law, International
• Economics and business
• Miscellaneous
• Psychology
• Sociology and anthropology
• Theory (including evolutionary theory)

Type:

• Biological applications - specific species (empirical studies of specific animals or insects)
• Deductive
• Empirical (includes qualitative and quantitative studies of humans, organizations, or use of archival data)
• Simulation (has a predefined universe of rules)
• Tournament (has submitted rules)

OTHER:

• Collateral research (work that does not directly build on Axelrod's, but is related to the concepts and assumptions in his work)

• 1. Abbott, Kenneth W. 1989. "Modern International Relations Theory: A Prospectus for International Lawyers." Yale Journal of International Law 14:335-411.
  • A review of leading contributions to the field of international relations and their relevance to international law. International law has fallen behind other law fields in developing an analytical approach; by linking the work in international relations to international law, Abbott hopes to suggest how international law might apply these tools theoretically and empirically. He reviews fundamental concepts, such as Waltz's three images of international relations and the rational actor approach. He discusses the contributions of game theory by describing a number of games, including Harmony, Deadlock, Stag Hunt, coordination games, and the PD. He argues that the PD illustrates why states seek cooperation, but also why it is so difficult to achieve. He considers examples of the PD in international relations, such as the security dilemma and competition to expand alliances, and notes the importance of repeated play and the magnitude of the payoffs to cooperation. Abbott suggests that norms such as proportionality embody the characteristics of TFT, and that regimes may help to alleviate states' monitoring problems. In the final section he discusses the Limited Test Ban and Nuclear Nonproliferation Treaties as legal means for the United States and the former Soviet Union to resolve PD situations. - abstract by LD Payoffs/Norms/Politics and law - international.
  
  
• 2. Abreu, Dilip, Paul Milgrom and David Pearce. 1991. "Information and Timing in Repeated Partnerships." Econometrica 59:1713-1733.
  • In a repeated partnership game with imperfect monitoring, [the authors] distinguish among the effects of (1) reducing the interest rate, (2) shortening the period over which actions are held fixed, and (3) shortening the lag with which accumulated information is reported. All three changes are equivalent in games with perfect monitoring. With imperfect monitoring, reducing the interest rate always increased the possibilities for cooperation, but the other two changes always have the reverse effect when the interest rate is small. Interactions/Payoffs/Noise/Economics and business/Theory/Deductive.
  
  
• 3. Akimov, Vladimir and Mikhail Soutchanski. 1994. "Automata Simulation of N-Person Social Dilemma Games." Journal of Conflict Resolution 38:138-148.
  • Collective behavior of N players in a social dilemma game is simulated by automata exhibiting cooperative behavior. In his models of simple biological systems, Tsetlin assumed minimum information available to the players. The automata in this study were somewhat more sophisticated, using Markov strategies in their interactions. The authors investigated relationships between information received by the automata and the emergence of cooperation in a simulated evolution process. In some ways, this approach is similar to that of Axelrod. However, instead of determining the most successful strategy, the authors seek surviving strategies in a social dilemma environment. Previous results showed that cooperation could be established asymptotically under partially centralized control. In this model there is no such control. The main result is that more sophisticated behavior of self-seeking automata compensates for the absence of such control Moreover, cooperation is established more rapidly when more information is available to the automata. Interactions/Limited set of allowable rules - finite state machines/Automata theory/Simulation.
• 4. Andreoni, James and John H. Miller. 1993. "Rational Cooperation in the Finitely Repeated Prisoner's Dilemma: Experimental Evidence." Economic Journal 103:570-585.
  • In a finite repeated PD, defection is the dominant strategy for both players, but if players have incomplete information, then cooperation in early rounds of the game can be rational (i.e., it can be rational to pretend to be altruistic) in order to develop a reputation for cooperation. The authors use two sets of experiments to examine cooperation in a finitely repeated PD where subjects' beliefs about other players' types (how altruistic the other players are) is manipulated. They considered two questions: first, the sequential equilibrium reputation hypothesis, in which people rationally build reputations; and second, whether some proportion of the population actually has altruistic motives. The experimental results indicated that there was support for the sequential equilibrium reputation hypothesis; subjects seemed to try to build a reputation for altruism. There also appeared to be some people who were altruistic, based on a control group that player a series of single-shot PDs. The authors suggest that all models of altruism are some combination of three models: pure altruism, where players care about others' payoffs; duty, where players feel an obligation to cooperate; and reciprocal altruism. Focusing on reciprocal altruism, they argue that players do not have to be irrational or altruistic in order to cooperate, as long as they believe that other altruistic players exist in the population. They ran a second experiment, the results of which again supported a reputation building hypothesis, and were consistent with the claim that altruistic types exist within the population. abstract by LD Interactions/Population structure/Reputation/Empirical.
• 5. Aumann, Robert J. and Sylvain Sorin. 1989. "Cooperation and Bounded Recall." Games and Economic Behavior 1:5-39.
  • The authors suggest that some irrationality, such as a perturbation, must be built into the system in order to achieve cooperation. A primary conclusion here is that evolution in the simulations is not toward TFT. - LD A two-person game has common interests if there is a single payoff pair z that strongly Pareto dominates all other payoff pairs. Suppose such a game is repeated many times, and that each player attaches a small but positive probability to the other playing some fixed strategy with bounded recall, rather than playing to maximize his payoff. Then the resulting supergame has an equilibrium in pure strategies, and the payoffs to all such equilibria are close to optimal (i.e., to z). Payoffs/Limited set of allowable rules - limited rationality/Theory/Automata theory/Deductive.
• 6. Axelrod, Robert. 1992. "How to Promote Cooperation." Current Contents 24:10.
  • This "Citation Classic" report is a personal statement of the origins, development and effect of my work on cooperation. My interests in artificial intelligence and game theory, and a concern with international politics led to the development of the computer tournament for the Prisoner's Dilemma. I believe the work has been well cited because it fits a widespread desire to prove a "hardheaded" rationale for cooperation, because it is easy to understand, and because it is general enough to be applicable to a wide range of disciplines. - abstract by RA Politics and law - international/Tournament.
• 7. Axelrod, Robert and Douglas Dion. 1988. "The Further Evolution of Cooperation." Science 242:1385-1390.
  • Axelrod's model of the evolution of cooperation was based on the iterated Prisoner's Dilemma. Empirical work following this approach has helped establish the prevalence of cooperation based on reciprocity. Theoretical work has led to a deeper understanding of the role of other factors in the evolution of cooperation: the number of players, the range of possible choices, variation in the payoff structure, noise, the shadow of the future, population dynamics, and population structure. Interactions/Choices/Payoffs/Noise/Population dynamics/Population structure/Theory.
• 8. Badcock, Christopher. 1991. Evolution and Individual Behavior: An Introduction to Human Sociobiology. Oxford: Basil Blackwell.
  • An introductory text of recent applications of evolutionary theory to humans. The introduction provides a brief discussion of Darwin's thought on natural selection and reproductive success, and an overview of the puzzle of altruism and cooperation in evolutionary terms. Chapter 1 has a fairly extensive discussion of The Evolution of Cooperation, including the success of TFT, the emergence of cooperation in iterated play of the PD, and the evolution of altruism within clusters of discriminating individuals. Chapter 2 considers three different types of altruism (kin, reciprocal and induced) and maps four different types of social action between two people on to the four cells of the PD. Chapter 3 discusses the importance of being able to identify others as potential cooperators and how such recognition might have evolved. Other chapters in the book focus on male and female behaviors, the relationships between parents and children, the link between these results and Freud, and the nature of culture. - abstract by LD Interactions/Population structure - information requirements/Sociology and anthropology/Biological applications.
• 9. Bendor, Jonathan. 1993. "Uncertainty and the Evolution of Cooperation." Journal of Conflict Resolution 37:709-734.
  • It is well known that inferential errors can induce nice but provocable strategies to engage in vendettas with each other. It is therefore generally believed that imperfect monitoring reduces the payoffs of such strategies and impairs the evolution of cooperation. The current literature, however, only scrutinizes specific strategies, either analytically or in particular tournaments. This article examines in a more general way how monitoring uncertainty affects the fate of cooperation in tournaments of the iterated prisoner's dilemma (IPD). The first set of results shows that imperfect monitoring does create a sharp trade-off between cooperativeness and unexploitability. The second set examines how random shocks affect the tournament payoffs of several large classes of strategies in the IPD, and shows how noise can help certain nice strategies. The third set analyzes how imperfect monitoring can facilitate the emergence of cooperation based on a population of non-nice strategies. Thus the idea that inferential uncertainty always harms nice strategies and always impairs the evolution of cooperation must by sharply qualified. Payoffs - comparing different PD matrices/Noise - misimplementation/Noise - misperception/Population dynamics - ESS/Theory/Deductive.
• 10. Bendor, Jonathan, Roderick M. Kramer and Suzanne Stout. 1991. "When in Doubt. . .: Cooperation in a Noisy Prisoner's Dilemma." Journal of Conflict Resolution 35:691-719.
  • The results suggest that generosity in a noisy environment dampens unintended vendettas. - LD In the last decade, there has been a resurgence of interest in problems of cooperation, stimulated largely by Axelrod's work. Using an innovative tournament approach, Axelrod found that a simple strategy, tit-for-tat (TFT) was most successful in playing the repeated prisoner's dilemma (PD) in a noiseless environment. However, recent analytical work has shown that monitoring problems caused by noise significantly impair TFT's effectiveness. The primary purpose of the present approach is to discover whether there exist alternative strategies that perform well in noisy PDs. To investigate this question, the authors conducted a computer tournament. The results of the tournament demonstrated that, consistent with analytical work, TFT performed rather poorly. In contrast, strategies that were generous (i.e., cooperated more than their partners did) were quite effective. Noise/Psychology/Tournament.
• 11. Bendor, Jonathan and Dilip Mookherjee. 1987. "Institutional Structure and the Logic of Ongoing Collective Action." American Political Science Review 81:129-154.
  • Work by Axelrod, Hardin, and Taylor indicates that problems of repeated collective action may lessen if people use decentralized strategies of reciprocity to induce material cooperation. Hobbes's centralized solution may thus be overrated. [Bendor and Mookherjee] investigate these issues by representing ongoing collective action as an n-person repeated prisoner's dilemma. The results show that decentralized conditional cooperation can ease iterated collective action dilemmas - if all players perfectly monitor the relation between individual choices and group payoffs. Once monitoring uncertainty is introduced, such strategies degrade rapidly in value, and centrally administered selective incentives become relatively more valuable. Most importantly, [the authors] build on a suggestion of Herbert Simon by showing that a hierarchical structure, with reciprocity used in subunits and selective incentives centrally administered, combines the advantages of the decentralized and centralized solutions. The hierarchical form is more stable than the decentralized structure and often secures more cooperation than the centralized structure. Generally, the model shows that the logic of repeated decision making has significant implications for the institutional forms of collective action. Interactions/Payoffs/Noise/Population size/Population structure/Politics and law - domestic/Politics and law - international/Sociology and anthropology/Theory/Deductive.
• 12. Bendor, Jonathan and Dilip Mookherjee. 1990. "Norms, Third-Party Sanctions, and Cooperation." Journal of Law, Economics, and Organization 6:33-63.
  • Social norms aid in cooperation in three ways: decision makers internalize them; those injured by norm violations punish the violator; and unaffected third parties punish the violator of the norms. The authors consider here what third party interactions and sanctions contribute to cooperation beyond bilateral interactions and sanctions. Do such sanctions always facilitate cooperation, and when are such sanctions most effective? Under very restrictive conditions, third party sanctions did not contribute independently to cooperation beyond the effects of bilateral sanctions. Third party sanctions were effective when there was asymmetry in the pair relationship. They were effective in facilitating cooperation when interactions between different pairs of players were linked, and at intermediate values of the discount rate. The authors also explored the role of coalition size and exploitation of the majority by the minority. - abstract by LD Payoffs/Population size/Norms/Reputation/Theory/Deductive.
• 13. Betz, Brian. 1991. "Response to Strategy and Communication in an Arms Race-Disarmament Dilemma." Journal of Conflict Resolution 35:678-690.
  • Subjects (40 males and 40 females) played against a simulated other in a six-choice prisoner's dilemma game that was described in terms of an arms race. The simulated other employed either a GRIT or tit-for-tat strategy, with either communication or no communication. The GRIT strategy elicited more cooperation than the tit-for-tat strategy, and there was an interaction such that the GRIT strategy with communication produced more cooperation than any of the other conditions. In addition, explicit communication decreased the occurrence of deception being employed against the GRIT strategist. Although GRIT produced more conciliation than tit-for-tat, the simulated other using GRIT was also taken advantage of more frequently; to avoid exploitation, modifications in the GRIT strategy may be needed. The results are discussed in terms of how explicit communication is needed for GRIT to be optimally effective and how additional communication may reduce exploitation. Payoffs - comparing different PD matrices/Population structure - information requirements/Limited set of allowable rules - enumerated set/Politics and law - international/Empirical.
• 14. Bicchieri, Cristina. 1990. "Norms of Cooperation." Ethics 100:838-861.
  • Argues that instrumental rationality approaches are inadequate to explain how norms become established and why people adhere to them. Bicchieri suggests that an evolutionary approach to norms provides better answers to these questions. She defines social norms as "the outcome of learning in a strategic interaction context; hence, they are a function of individual choices and, ultimately, of individual preferences and beliefs" (p. 839). Norms are clusters of expectations, or conditional preferences which thus depend on the preferences of others. Because of this dependence on other's preferences, norms are better modeled as a coordination game rather than a zero sum game. Examining the two and n-person PDs, Bicchieri explores the conditions under which cooperation is rational. She argues that once a cooperative equilibrium is established, it is likely to persist because future decisions will be based on past choices. Yet establishing cooperation in a large group is likely to be difficult since individual choice has a negligible effect on the outcome and defection can go undetected. Bicchieri proposes that cooperation can become well established in small groups and then diffuse through an evolutionary process to larger groups. - abstract by LD Interactions/Payoffs - comparing different PD matrices/Noise - misperception/Population dynamics - replicator dynamics/Population structure - information requirements/Norms/Limited set of allowable rules - limited rationality/Deductive.
• 15. Binmore, Kenneth and Larry Samuelson. 1992. "Evolutionary Stability in Repeated Games Played by Finite Automata." Journal of Economic Theory 57:278-305.
  • [The authors] consider a game in which "meta-players" choose finite automata to play a repeated stage game. Meta-players' utilities are lexicographic, first increasing in the (limit-of-the-means) payoffs of the repeated game and second decreasing in the number of states in their automaton. [The authors] examine the outcomes in this game which satisfy a version of evolutionary stability that has been modified to permit existence. [The authors] find that such automata must be efficient, in that they must maximize the sum of the (limit-of-the-means) payoffs from the repeated game. Population dynamics - ESS/Population structure - information requirements/Limited set of allowable rules - finite state machines/Limited set of allowable rules - limited rationality/Automata theory/Theory/Deductive/Simulation.
• 16. Bolle, Friedel and Peter Ockenfels. 1990. "Prisoners' Dilemma as a Game with Incomplete Information." Journal of Economic Psychology 11:69-84.
  • The Prisoners' Dilemma is reformulated as a game (with incomplete information) between players of different 'moral standards'. Equilibrium solutions are computed for games with simultaneous choices and for games with sequential choices. Cooperation should occur more frequently in the latter. Experiments are conducted with both types of games. The results can neither be explained by (linear) altruistic utility functions nor by a revaluation of the cooperative choices. They can be explained, however, by a revaluation of the cooperative result. In this case [the authors] get an extreme distribution of the 'moral standards'. Expressed as monetary values and compared with the monetary rewards of the game there seems to be one class of persons with rather high standards, another class of persons with rather low standards, and practically no intermediate cases. The rejection of altruistic utility functions as well as the rejection of certain norms of behavior have important consequences for the implementation of altruism, norms and morals in formal models of decision making. Payoffs - comparing different PD matrices/Norms/Theory/Psychology/Deductive/Empirical.
• 17. Borstnik, B., D. Pumpernik, I. L. Hofacker and G. L. Hofacker. 1990. "An ESS-analysis for Ensembles of Prisoner's Dilemma Strategies." Journal of Theoretical Biology 142:189-200.
  • The ESS (Evolutionary Stable Strategy) concept of Maynard Smith can be applied in its weak form to ensembles of competing PD ("Prisoner's Dilemma") strategies memorizing two to three of one's own and one's opponent's moves. The format of our study is:
    • (1) games have very long duration;
    • (2) Taylor-Jonker dynamics applies;
    • (3) Effects of finite population size can be ignored.
    It is shown that in the case R>(T+S)/2 a set of strategies can be singled out which do not lose against any other strategy while co-operating with themselves. Such a set is uninvadable by other PD strategies if it constitutes more than half of the total population. Population dynamics - ESS/Population dynamics - replicator dynamics/Simulation.
• 18. Bower, B. 1992. "Cooperation Evolves in Computer Tourney." Science News 141:39.
  • Discusses the results from M. Nowak and K. Sigmund (1992) "Tit for Tat in Heterogeneous Populations." Nature 355:250-253. See also H.C.J. Godfray (1992) "The Evolution of Forgiveness." Nature 355:206-207. Recent computer tournament results suggest that natural selection can favor reciprocal altruism in the form of TFT strategies. Reports the results from an article by M. Nowak and K. Sigmund in which they found that TFT facilitates the emergence of cooperation in a population of selfish players. When TFT strategies were not included in the population, selfish strategies prevail and cooperation does not evolve. Bower repeats Godfray's suggestion that evolution may favor simple rules and the cooperation may evolve more easily in nature where players interact with known others regularly. - abstract by LD Population dynamics - ESS/Population structure - clustering/Population structure - spatial models/Simulation.
• 19. Boyd, Robert. 1992. "The Evolution of Reciprocity when Conditions Vary." In Alliance Formation among Male Baboons: Shopping for Profitable Partners, edited by Alexander H. Harcourt and Frans B.M. de Waal, pp. 473-489. Oxford: Oxford University Press.
  • Reviews work on reciprocal cooperation using the PD paradigm and suggests that some of this work makes unrealistic assumptions. Boyd presents and analyzes three variants of the PD in which game conditions vary. In each case, there is a range for which the basic results of Axelrod's and others' work remains unchanged, but for some parameter ranges altering these assumptions affects the evolutionary selection and stability of TFT-like strategies. The first model allows payoffs to vary among individuals. Boyd finds that selection may favor strategies that result in in a system of unbalanced reciprocity. In the case where payoffs vary among interactions, a wide range of strategies may be ESS. Finally, if the expected number of interactions is allowed to vary, suspicious strategies that delay the initiation of cooperation may be favored. Boyd concludes by noting that "the fact that distinctive reciprocating strategies are favoured in different circumstances may provide an avenue for empirical detection of reciprocity using the comparative method" (p. 487). - abstract by LD Payoffs - comparing different PD matrices/Population dynamics/Population structure/Limited set of allowable rules - enumerated set/Deductive
• 20. Boyd, Robert. 1988. "Is the Repeated Prisoner's Dilemma a Good Model of Reciprocal Altruism?" Ethology and Sociobiology 9:211-222.
  • Axelrod and Hamilton (1981) used the repeated prisoner's dilemma game as a basis for their widely cited analysis of the evolution of reciprocal altruism. Recently, it has been argued that the repeated prisoner's dilemma is not a good model for this task. Some critics have argued that the single period prisoner's dilemma represents mutualistic rather than altruistic social interactions. Others have argued that reciprocal altruism requires that the opportunities for altruism occur sequentially, first one individual and then after some delay the other. Here [Boyd] begin[s] by arguing that the single period prisoner's dilemma game is consistent with the definition of altruism that is widely accepted in evolutionary biology. Then [Boyd] present[s] two modified version of the repeated prisoner's dilemma, one in which behavior is sequential, and a second in which behavior occurs in continuous time. Each of these models shares the essential qualitative properties with the version used by Axelrod and Hamilton. Payoffs - comparing different PD matrices/Population dynamics - ESS/Population structure/Limited set of allowable rules - enumerated set/Theory/Deductive.
• 21. Boyd, Robert. 1989. "Mistakes Allow Evolutionary Stability in the Repeated Prisoner's Dilemma Game." Journal of Theoretical Biology 136:47-56.
  • The repeated prisoner's dilemma game has been widely used in analyses of the evolution of reciprocal altruism. Recently it was shown that no pure strategy could be evolutionarily stable in the repeated prisoner's dilemma. Here [Boyd] show[s] that if there is always some probability that individuals will make a mistake, then a pure strategy can be evolutionarily stable provided that it is "strong perfect equilibria" against itself. To be a strong perfect equilibrium against itself, a strategy must be the best response to itself after every possible sequence of behavior. [Boyd] show[s] that both unconditional defection and a modified version of tit-for-tat have this property. Noise - misimplementation/Population dynamics - ESS/Population dynamics - replicator dynamics/Theory/Deductive.
• 22. Boyd, Robert and Peter J. Richerson. 1990. "Culture and Cooperation." In Beyond Self-Interest, edited by Jane J. Mansbridge, pp. 111-132. Chicago: University of Chicago Press.
  • Examines the question of why human, unlike other mammals, cooperate in large groups of unrelated individuals. Kinship and reciprocity explain cooperation in small groups, but not large. Boyd and Richerson suggest one possible solution to this puzzle is that of cultural selection. In order for an explanation of cultural selection to work, there needs to be some mechanism which maintains cultural differences and variation, or otherwise populations of defectors would spread more quickly than those of cooperators. A theory of cultural selection must also describe the social or psychological mechanisms at work that could counter influences at the level of individual genes. Boyd and Richerson construct a simple model of group selection with four basic processes: enculteration, individual learning, the flow of ideas in society, and the extinction of societies. Using this model, defectors spread quickly and cooperation exists only among small groups. They add a fifth factor to the model, conformist cultural transmission, in which children acquire disproportionately the more common adult trait. With the addition of this process, the authors find that groups of cooperators can be selected. The authors briefly draw out some of the implications of their findings, including those for the kinds of trait transmitted, conformist traditions versus individual learning, and ethnic cooperation and conflict. - abstract by LD Interactions/Population structure - clustering/Population size/Sociology and anthropology/Theory
• 23. Boyd, Robert and Peter J. Richerson. 1988. "The Evolution of Reciprocity in Sizable Groups." Journal of Theoretical Biology 132:337-356.
  • Recently, several authors have investigated the evolution of reciprocal altruism using the repeated prisoner's dilemma game. These models suggest that natural selection is likely to favor behavioral strategies leading to reciprocal cooperation when pairs of individuals interact repeatedly in potentially cooperative situations. Using the repeated n-person prisoner's dilemma game, [the authors] consider whether reciprocal altruism is also likely to evolve when social interactions involve more individuals. [The authors] show that the conditions that allow the evolution of reciprocal cooperation become extremely restrictive as group size increases. Interactions/Population dynamics - ESS/Population structure/Theory/Deductive.
• 24. Boyd, Robert and Peter J. Richerson. 1989. "The Evolution of Indirect Reciprocity." Social Networks 11:213-236.
  • Human societies are based on cooperation among large numbers of genetically unrelated individuals. This behavior is puzzling from an evolutionary perspective. Because cooperators are unrelated it cannot be the result of kin selection, and the large scale seems to preclude explanations based on direct reciprocity. Alexander (1987) has proposed that large-scale cooperation among humans can be understood as resulting from networks of "indirect" reciprocity. For example, individual A may help individual B even though A receives no direct reciprocal benefit. Instead, B might help C who helps D who finally returns the help indirectly to A. Here [Boyd and Richerson] describe a simple mathematical model of the evolution of indirect reciprocity. Analysis of this model suggests that indirect reciprocity is unlikely to be important unless interacting groups are fairly small. Limited set of allowable rules - enumerated set/Theory/Deductive.
• 25. Boyd, Robert and Peter J. Richerson. 1990. "Group Selection among Alternative Evolutionarily Stable Strategies." Journal of Theoretical Biology 145:331-342.
  • Many important models of the evolution of social behavior have more than one evolutionarily stable strategy (ESS). Examples include co-ordination games, contests, mutualism, reciprocity, and sexual selection. Here [the authors] show that when there are multiple evolutionarily stable strategies, selection among groups can cause the spread of a strategy that has the lowest extinction rate or highest probability of contributing to the colonization of empty habitats, and that this may occur even when groups are usually very large, migration rates are substantial, and "extinction" entails only the disruption of the group and the dispersal of its members. The main requirements are: (1) individuals drawn from a single suriving group make up a sufficiently large fraction [of] newly formed groups, and (2) the processes increasing the frequency of successful strategies within groups are strong compared to rate of migration among groups. The latter condition suggests that this form of group selection will be particularly important when behavioral variation is culturally acquired. Population dynamics - ESS/Population structure/Sociology and anthropology/Theory/Deductive.
• 26. Boyd, Robert and Peter J. Richerson. 1992. "Punishment Allows the Evolution of Cooperation (or Anything Else) in Sizable Groups." Ethology and Sociobiology 13:171-195.
  • Existing models suggest that reciprocity is unlikely to evolve in large groups as a result of natural selection. In these models, reciprocators punish noncooperation by withholding future cooperation, and thus also penalize other cooperators in the group. Here, [the authors] analyze a model in which the response is some form of punishment that is directed solely at noncooperators. [Boyd and Richerson] refer to such alternative forms of punishment as retribution. [They] show that cooperation reinforced by retribution can lead to the evolution of cooperation in two qualitatively different ways. (1) If benefits of cooperation to an individual are greater than the costs to a single individual of coercing the other n - 1 individuals to cooperate, then strategies which cooperate and punish noncooperators, strategies which cooperate only if punished, and, sometimes, strategies which cooperate but do not punish will coexist in the long run. (2) If the costs of being punished are large enough, moralistic strategies which cooperate, punish noncooperators, and punish those who do not punish noncooperators can be evolutionarily stable. [Boyd and Richerson] also show, however, that moralistic strategies can cause any individually costly behavior to be evolutionarily stable, whether or not it creates a group benefit. Interactions/Noise - misimplementation/Endogenous ending/Population dynamics - ESS/Population size/Theory/Deductive/Sociology and anthropology.
• 27. Brelis, Matthew. 1992. "Reputed Mobster Defends His Honor." Boston Globe, 18 March, section 1:23.
  • The story of a reputed mobster, Vincent Ferrara, who called the Boston Globe because he was concerned about a story that had appeared in the paper that reported that he would testify against a mob boss. Ferrara said that he had not agreed to testify, and that the story the paper had run threatened the reputation he had earned for himself by making him look like an informant. He also said that such a story might prove harmful to him in the future. The situation resembles the story of the PD with a twist: here the prisoner wants to cooperate in order to maintain his reputation (and his health). - abstract by LD Interactions/Payoffs/Reputation/Politics and law - domestic/Miscellaneous.
• 28. Browne, Malcolm W. 1988. "Some Thoughts on Self-Sacrifice." New York Times, 5 July, 24.
  • Considers situations in nature in which organisms sacrifice themselves for the good of the community. Discusses a study that looked at sperm cells in rats and found that up to fifty percent of the cells were deformed. The researchers suggested that the deformities might serve some biological purpose. They found that after healthy sperm cells enter the reproductive tract of a female rat, the deformed sperm mass together, form a plug, and die, thereby preventing other sperm form fertilizing the egg and guaranteeing "genetic victory" to one of the first arrivals. Browne suggests that this is an example of social cooperation, and considers other examples of self sacrifice for community good, including runt tadpoles that do not compete with better developed siblings for nutrients, but do compete with non-siblings. - abstract by LD Biological applications.
• 29. Bull, J.J. and W.R. Rice. 1991. "Distinguishing Mechanisms for the Evolution of Co-operation." Journal of Theoretical Biology 149:63-74.
  • The existence of co-operation between species has been cast as a problem to the selfish-gene view of evolution: why does co-operation persist, when it would seem that individual selection should favor the unco-operative individual who exploits the co-operative tendencies of its partner and gives nothing in return? The recent literature has emphasized one type of model as underlying the evolution and stability of interspecific co-operation, which [Bull and Rice] term the "partner-fidelity" model, and which is typified by the game theory model known as the iterated Prisoner's Dilemma game. Under this mechanism, individuals are associated with the same partner(s) during an indefinite sequence of interactions. Individuals who at any time fail to co-operate with their partner can be penalized by those same partners in subsequent trials, hence the co-operation can be evolutionarily stable. Many examples of biological co-operation that have been offered appear to conform to this model. However, a few examples appear instead to fit a different and unrecognized mechanism, termed "partner-choice". Under partner-choice, individuals are associated for just one interaction, but an asymmetry enables one member to differentially reward co-operative vs. unco-operative partners in advance of any possible exploitation. Possible examples of co-operation maintained through partner-choice mechanisms are provided by the yucca/yucca moth system and the fig/fig wasp system. Population structure - information requirements/Biological applications/Theory.
• 30. Bunn, George and Rodger A. Payne. 1988. "Tit-for-tat and the Negotiation of Nuclear Arms Control." Arms Control 9:207-233.
  • Discussion of the advantages and difficulties of applying TFT strategies to arms control negotiations. PD situations differ from two person negotiations in two ways: negotiations allow for communication, and there are many more choices or options available. In the PD, there is no communication between the players, and there are only two options, to cooperate or to defect. TFT like strategies could fit arms control negotiations for several reasons (for example, TFT models the action-reaction that precedes bargaining; empirical work suggests that TFT-like strategies describe the actual behavior of the superpowers). Ultimately, however, the authors argue that TFT is better as a means to initiate negotiations, rather than a model for them once they begin. In particular, it is difficult to meet the four characteristics of TFT in reality. First, clarity is difficult in a bargaining situation: there is some chance of misperception, the choices are not always clear, and different issue are often linked together. Second, being unilaterally nice may be dangerous to a country's national security. Third, reciprocity is difficult given real world time demands; for example, democracies may not be able to respond quickly, given the number of different actors involved in decision making (the public, the legislature, etc.). Finally, episodes of cheating are often highly publicized as a form of leverage in the negotiations process. Thus, there are several theoretical and practical difficulties in applying TFT strategies to arms control negotiations. However, the authors note two practical implications of their discussion: first, TFT strategies may be useful in getting negotiations started, and second, through communication in the bargaining process the PD may be transformed into a more cooperative game. - abstract by LD Politics and law - international.
• 31. Busch, Marc L. and Eric R. Reinhardt. 1993. "Nice Strategies in a World of Relative Gains: The Problem of Cooperation under Anarchy." Journal of Conflict Resolution 37:427-445.
  • The debate between neoliberals and realists in the field of international relations draws heavily on the findings offered in Robert Axelrod's Evolution of Cooperation. Axelrod's well-known argument is that cooperation can emerge among egoists despite the absence of a central authority. This article assesses the robustness of Axelrod's findings in light of the realist critique that relative gains concerns make cooperation less likely than neoliberals contend. [Busch and Reinhardt] build on an amended prisoner's dilemma (PD) game and conduct a computer simulation tournament in which [they] vary (1) the payoff structure and (2) Axelrod's population of strategies. The results indicate that cooperation can emerge even under strong relative gains concerns, so long as the population of strategies is sufficiently retaliatory. On the basis of this finding, [the authors] argue that the realist critique is overstated: the introduction of greater relative gains concerns does not necessarily limit the prospects for cooperation among states. Payoffs - comparing different PD matrices/Relative vs. absolute gains/Politics and law - international/Simulation.
• 32. Buss, David M. 1991. "Evolutionary Personality Psychology." Annual Review of Psychology 42:459-91.
  • Describes the linkage between evolutionary psychology and personality psychology. Evolutionary theory has the potential to organize "seemingly arbitrary personality theories by anchoring a theory of human nature in processes known to govern all life. . . . Personality theories inconsistent with evolutionary theory stand little chance of being correct" (p. 461). There are three parts of evolutionary personality theory (pp. 476-477). First is the identification of adaptive problems faced by ancestral populations. Second, consider the relationship between current, observable personality factors and the proposed problems faced by ancestors. The theory must show how current personality features solve or solved these problems. Finally, the theory must explain individual differences in the adoption and use of behavioral strategies produced by these underlying psychological mechanisms. Buss uses an evolutionary perspective to re-frame the central questions and concerns of personality theory, including problems of consistency, interactionism, the role of context and environment, emotions, and culture. - abstract by LD Biological applications/Sociology and anthropology/Psychology/Theory/Collateral research.
• 33. Caporael, Linnda R., Robyn M. Dawes, John M. Orbell and Alphons J.C. van de Kragt. 1989. "Selfishness Examined: Cooperation in the Absence of Egoistic Incentives." Behavioral and Brain Sciences 12:683-739.
  • Social dilemmas occur when the pursuit of self-interest by individuals in a group leads to less than optimal collective outcomes for everyone in the group. A critical assumption in the human sciences is that people's choices in such dilemmas are individualistic, selfish, and rational. Hence, cooperation in the support of group welfare will only occur if there are selfish incentives that convert the social dilemma into a nondilemma. In recent years, inclusive fitness theories have lent weight to such traditional views of rational selfishness on Darwinian grounds. To show that cooperation is based on selfish incentives, however, one must provide evidence that people do not cooperate without such incentives. In a series of experimental social dilemmas, subjects were instructed to make single, anonymous choices about whether or not to contribute money for a shared "bonus" that would be provided only if enough other people in the group also contributed their money. Noncontributors cited selfish reasons for their choices; contributors did not. If people are allowed to engage in discussion, they will contribute resources at high rates, frequently on irrational grounds, to promote group welfare. These findings are consistent with previous research on ingroup biasing effects that cannot be explained by "economic man" or "selfish gene" theories. An alternative explanation is that sociality was a primary factor shaping the evolution of Homo sapiens. The cognitive and affective mechanisms underlying such choices evolved under selection pressures on small groups for developing and maintaining group membership and for predicting and controlling the behavior of other group members. This sociality hypothesis organized previously inexplicable and disparate phenomena in a Darwinian framework and makes novel predictions about human choice. Peer responses and commentaries follow. Interactions/Sociology and anthropology/Psychology/Empirical.
• 34. Carrasco, Enrique R. 1993. "Chile, Its Foreign Commercial Bank Creditors and Its Vulnerable Groups: An Assessment of the Cooperative Case-by-Case Approach to the Debt Crisis." Law and Policy in International Business 24:273-389.
  • Uses game theory to consider the question of why the cooperative case-by-case approach to the Latin American debt crisis was successful. Chile was the first Latin American country to adopt a highly cooperative approach to dealing with its debt problems: it made an effort to meet its obligations, and in return expected creditors to help restructure debt and re-establish access to the voluntary lending market and economic growth. Carrasco argues that the Latin American debtors and their creditors faced a negotiator's dilemma, a form of the PD, since cooperative approaches created value through cooperative ventures for both debtors and creditors, but simply competition to claim value or success did not substantively aid either party. Carrasco suggests that the case-by-case approach implicitly heeds Axelrod's advice not to defect first, to reciprocate, and not to be too clever. Relative to other Latin American countries, Chile's efforts with this cooperative approach yielded debt reduction and economic growth. However, Carrasco argues that this cooperation between Chile and its creditors succeeded in part because it was subsidized by the most vulnerable groups in Chile (e.g., the poor), who suffered the most when the country attempted to meet its international financial commitments. The failure of the case-by-case approach was that it did not address the costs that cooperation imposed on the vulnerable. - abstract by LD Payoffs/Politics and law - international/Economics and business.
• 35. Ceccatto, H.A. and B.A. Huberman. 1989. "Persistence of Nonoptimal Strategies." Proceedings of the National Academy of Sciences, USA 86:3443-3446.
  • For other work on asynchronous choices, see B.A. Huberman and N.S. Glance (1993) "Evolutionary Games and Computer Simulations." PNAS, USA 90:7716-7718. For work that uses thermodynamic models to model cooperation, see N.S. Glance and B.A. Huberman (1994) "The Dynamics of Social Dilemmas." Scientific American 270:76-81. Metastable configurations in open computational systems with local minima in their optimality functions are shown to be very long lived, which makes them effectively stable. When rare transitions to the global optimum do occur, they happen extremely fast, in analogy to models of punctuated evolution in biology. These results are obtained by introducing a thermodynamic-like formalism that allows for a simple analysis of nonlinear game dynamics in computational systems. Interactions/Payoffs/Population dynamics - ESS/Population dynamics - replicator dynamics/Population structure/Theory/Deductive/Simulation/Collateral research.
• 36. Chagnon, Napoleon A. 1988. "Life Histories, Blood Revenge, and Warfare in a Tribal Population." Science 239:985-992.
  • The revenge pattern Chagnon discusses resembles TFT. Swift retaliation for offenses served as a deterrent over the long run; those who avenged kin deaths enjoyed greater reproductive success. - LD Blood revenge is one of the most commonly cited causes of violence and warfare in tribal societies, yet it is largely ignored in recent anthropological theories of primitive warfare. A theory of tribal violence is presented showing how homicide, revenge, kinship obligations, and warfare are linked and why reproductive variables must be included in explanations of tribal violence and warfare. Studies of the Yanomamo Indians of Amazonas during the past 23 years show that 44 percent of males estimated to be 25 or older have participated in the killing of someone, that approximately 30 percent of adult male dealths [sic] are due to violence, and that nearly 70 percent of all adults over an estimated 40 years of age have lost a close genetic relative due to violence. Demographic data indicate that men who have killed have more wives and offspring than men who have not killed. Sociology and anthropology/Empirical/Collateral research.
• 37. Coalitions and Alliances in Humans and Other Animals. 1992. Edited by Alexander H. Harcourt and Frans B.M. de Waal. Oxford: Oxford University Press.
  • An attempt to bring together important work on coalitions and alliances. Harcourt and de Waal distinguish between a coalition and alliance by stating that coalitions are one-time cooperative acts by one or more individuals against a third party, whereas alliances are ongoing cooperative relationships. Both coalitions and alliances can be seen as means of competition. The book is divided into three sections: coalitions, alliances and societal structure; cooperative strategies in the "political" arena; and evolutionary considerations. The individual chapters cover a wide range of topics and applications. Axelrod's work is cited in several of the chapters and introductions to the sections. - abstract by LD Interactions/Population structure/Biological applications/Sociology and anthropology/Politics and law - international/Psychology/Empirical.
• 38. Condlin, Robert J. 1992. "Bargaining in the Dark: The Normative Incoherence of Lawyer Dispute Bargaining Role." Maryland Law Review 51:1-104.
  • Considers the question of dispute settlements among lawyers. The situation resembles a PD in that lawyers promote their own interests by cooperating with each other, but ethical norms oblige lawyers to compete with each other and do their best to promote their clients' selfish goals. Condlin uses Axelrod's results and the PD to suggest that cooperative interactions are more likely when the parties believe that they will be involved in bargaining relationships in the future. He also notes that there are some problems with translating Axelrod's work into practice: the PD simplifies reality, and it is hard for one party to know what the other has done. Also, in contrast to their ethical obligations, Axelrod's analysis suggests that lawyers are better off in the long run by cooperating with each other. Condlin suggests that lawyers have developed stylized bargaining norms that allow them to signal their cooperativeness to other lawyers, but simultaneously to appear to defend their clients' interests zealously. Condlin concludes by considering some of the ways to resolve this dilemma: accept the system and do nothing; make cooperative bargaining more ethical; make ethical bargaining more practical for lawyers; or to rely on discretionary advocacy. - abstract by LD Norms/Politics and law - domestic.
• 39. Cooperation and Prosocial Behaviour. 1991. Edited by Robert A. Hinde and Jo Groebel. Cambridge: Cambridge University Press.
  • An edited volume which considers various aspects of cooperation. The primary topics include cooperation in animals and humans; the development of prosocial tendencies; the situational and personality determinants of prosocial behavior; trust, commitment, and cooperation; and cooperation between groups. Each section has a brief introductory editorial which serves as an overview or commentary on the topic. Axelrod is cited briefly in chapters 1, 2, and 15. - abstract by LD Population structure/Norms/Biological applications/Sociology and anthropology/Politics and law - domestic/Politics and law - international/Psychology.
• 40. Crawford, Vincent P. and Hans Haller. 1990. "Learning How to Cooperate: Optimal Play in Repeated Coordination Games." Econometrica 58:571-595.
  • This paper proposes a characterization of optimal strategies for playing certain repeated coordination games whose players have identical preferences. Players' optimal coordination strategies reflect their uncertainty about how their partners will respond to multiple-equilibrium problems; this uncertainty constrains the statistical relationships between their strategy choices players can bring about. [The authors] show that optimality is nevertheless consistent with subgame-perfect equilibrium. Examples are analyzed in which players use precedents as focal points to achieve and maintain coordination, and in which they play dominated strategies with positive probability in early stages in the hope of generating a useful precedent. Choices/Payoffs/Limited set of allowable rules - limited rationality/Theory/Deductive/Collateral research.
• 41. Dacey, Raymond and Norman Pendegraft. 1988. "The Optimality of Tit-For-Tat." International Interactions 15:45-64.
  • The paper examines the performance of tit-for-tat in iterated plays of prisoners' dilemma and chicken. In particular, the paper examines, via computer simulations, a space of surrogate Axelrod-type tournaments over these games. The surrogate tournaments are specified in terms of characteristics of strategies similar to those Axelrod identifies as fundamental. The paper shows that the zones of optimality for tit-for-tat in tournament play of both prisoners' dilemma and chicken remarkably constrained, but that tit-for-tat generally does well relative to other strategies. Furthermore, [the] results show that the success of tit-for-tat is sensitive to the number of players and the assignment of payoff values. Payoffs/Payoffs - comparing different PD matrices/Population size/Limited set of allowable rules - parameterized rules/Simulation.
• 42. Dawes, Robyn M., Alphons J.C. van de Kragt and John M. Orbell. 1990. "Cooperation for the Benefit of Us - Not Me, or My Conscience." In Beyond Self-Interest, edited by Jane J. Mansbridge, pp. 97-110. Chicago: University of Chicago Press.
  • Consider the class of social dilemmas, such as the PD, in which actions good for group members acting individually produce outcomes which are bad for the collective group. The authors note four ways to resolve such dilemmas, each of which relies on manipulating the consequences for the individual of cooperating or defecting: the Leviathan, reciprocal altruism and TFT from Axelrod's work, mutual coercion, and socially instilled consciences. Based on a series of experiments, the authors show that the rates of cooperation in the one-shot PD can be dramatically affected by group identity or solidarity, by allowing for discussion among subjects, even in the absence of factors such as reputation and future rewards and punishments. The authors conclude that "with no discussion, egoistic motives explain cooperation; with discussion, group identity - alone or in interaction with verbal promises - explains its dramatic increase" (p. 107). The authors also comment on methodology in previous experiments used to examine cooperation, particularly directions which instruct individuals to attend to relative gains or situations which examine only repeated interactions. - abstract by LD Interactions/Payoffs - comparing different PD matrices/Psychology/Empirical
• 43. Dawkins, Richard. 1989. The Selfish Gene: New Edition. Oxford: Oxford University Press.
  • New edition of the 1976 classic about the "gene's-eye view" of evolution. The original text of the book is unchanged in the new edition, although endnotes have been added to correct and update the original. There are also two new chapters. Chapter 12, "Nice Guys Finish First," draws heavily on Axelrod's work. Dawkins provides a relatively extensive description and discussion of Axelrod's book, including defining the PD, the importance of iteration, the round-robin tournaments, characteristics of successful strategies, the importance of environment, and the simulations. He considers how clusters might develop, especially through kinship. Dawkins shows how the PD might be applied to divorce situations, bacteria, fig wasps, sea bass and vampire bats, and he suggests that genes might have been unconsciously selected to play the PD as a rule of thumb. Chapter 13, "The Long Reach of the Gene," briefly discusses the question explored at length in Dawkins's book The Extended Phenotype. of why genes came together in large vehicles (such as individuals). - abstract by LD Population dynamics - ESS/Population structure - clustering/Biological applications/Sociology and anthropology/Theory.
• 44. Downs, George W. 1991. "Arms Races and War." In Behavior, Society, and Nuclear War, vol. 2, edited by Philip E. Tetlock, Jo L. Husbands, Robert Jervis, Paul C. Stern, and Charles Tilly, pp. 73-109. Oxford: Oxford University Press.
  • Examines the theoretical and methodological foundations of arms races and war, and the relationship between the two. No clear, reliable theory exists that describes the conditions or situations under which arms races lead to war. He reviews the empirical work on arms races, considering multiple case studies and aggregate analyses separately. Downs discusses some of the omissions and shortcomings in this work, and suggests that a theory which hopes to link arms races to war should include conditions under which deterrence can be sustained, the role of strategy among decision makers, and view changes in arms as a decision variable. He examines TFT as a possible prescription for decreasing the chances of arms races leading to war, because the arms balance is maintained. However, problems with using TFT arise when there is either an imbalance in resources or in arms between the two sides. Downs considers other aspects that should ideally be included in a theory linking arms races to war, including the challenges of the security dilemma and spiral theory, with the importance of misperception and their use of psychological theories. Ideally all of these factors should be incorporated into one model, although this integration is likely to be a gradual process. Downs reviews some work that has begun to address questions about misperception and the importance of understanding the assumptions that underlie various models. - abstract by LD Noise - misperception/Politics and law - international/Psychology
• 45. Druckman, Daniel and Benjamin J. Broome. 1991. "Value Differences and Conflict Resolution: Familiarity or Liking?" Journal of Conflict Resolution 35:571-593.
  • Effects of familiarity and liking on negotiating perceptions and behaviors are explored in two experiments, one focusing on prenegotiation expectations and perceptions (experiment 1), the other on negotiation processes and outcomes (experiment 2). Both experiments were embedded in the context of a simulation of conflict between groups resembling the Greek and Turkish communities in Cyprus. Results obtained in the two experiments showed different effects for the familiarity and liking variables: Analytically distinct effects for these variables on prenegotiation perceptions contrasted with the combined effects on negotiating behavior and postnegotiation perceptions. In experiment 1, liking influenced expected movement from initial positions, perceptions of the opponent, and types of strategies prepared for the negotiation; familiarity had its primary impact on perceptions of the situation as being conducive to agreement. Results of experiment 2 showed that reducing either liking or familiarity served to reduce willingness to reach compromise agreements, whether actual or desired. These results suggest that the positive effects obtained for a facilitation condition reported in an earlier study by Druckman, Broome, and Korper (1988) may have been due to the familiarity and liking produced by the experimental manipulation. Implications of the results obtained in both experiments are discussed in terms of changing expectations and uncertainty reduction. Further analyses of negotiating process dynamics would elucidate the difference between reaching agreements in the short run and developing relationships between groups over the long term. Politics and law - international/Psychology/Empirical/Collateral research.
• 46. Dugatkin, L.A. 1988. "Do Guppies Play TIT FOR TAT during Predator Inspection Visits?" Behavioral Ecology and Sociobiology 23:395-399.
  • Cooperative behavior during predator-inspection visits of the guppy (Poecilia reticulata) was examined. Wild caught guppies from Trinidad were tested on two types of mirror. In one treatment individual guppies were tested using a long mirror that ran parallel to the path toward the predator. In the second treatment, guppies were tested with a shorter mirror that was placed at an angle of thirty-two degrees to the path toward the predator. Guppies in both mirror treatments showed consistent behavior throughout a trial, with subjects in the straight-mirror treatment spending more time near the predator. It appears that guppies employ a "conditional-approach" strategy during predator inspections. The conditional-approach strategy instructs a player to swim toward the predator (inspect) on the first move of a game and subsequently only to move forward if the other player swims beside it. "Conditional-approach" is analogous to a TIT FOR TAT strategy, the difference being that the conditional-approach strategy makes no assumptions about the player's payoff matrix. Biological applications/Biological applications - specific species - fish.
• 47. Dugatkin, Lee Alan. 1992. "The Evolution of the "Con Artist"." Ethology and Sociobiology 13:3-18.
  • A series of game-theoretical models for the evolution of, what in the folk literature has become known as, the "Confidence Artist" is presented. Con artists are assumed to be noncooperators who move between groups and "prey" on naive cooperators. Cooperators learn about con artists by either direct experience or via cultural transmission about the identity (or behavior) of such individuals. Three types of transmission rules about con artists are modeled: 1) transmission rate that is independent of the frequency of con artists in the metapopulation; 2) transmission such that cooperators, with some probability, can learn about particular con artists who have entered their group; and 3) a type of frequency dependent transmission such that cooperators can identify con artists in proportion to their frequency in the metapopulation. In general, cultural transmission works against con artists by 1) decreasing the critical between travel patch travel time to invade a metapopulation of cooperators or 2) decreasing the equilibrial frequency of con artists (compared to the case of no cultural transmission). Depending on the mode of cultural transmission, con artists may exist at relatively high or low frequencies. Population structure - information requirements/Limited set of allowable rules - enumerated set/Biological applications/Sociology and anthropology/Simulation.
• 48. Dugatkin, Lee Alan. 1990. "N-person Games and the Evolution of Co-operation: A Model Based on Predator Inspection in Fish." Journal of Theoretical Biology 142:123-135.
  • Considers the potential importance of the relationship between population size and cooperative behavior. Dugatkin finds that cooperation may invade large populations more easily than smaller ones, but it is likely to represent a smaller proportion of the population in larger groups. - LD Two N-person game theoretical models examining the evolution of co-operation during predator inspection in fish are presented. Predator inspection occurs in small shoals of fish, in which one to a few individuals, the "inspectors" (co-operators) break away from the shoal and cautiously approach a predator to obtain information on this potential danger. In the models presented here, remaining with the shoal and not inspecting is considered an act of defection. Both model I and II produce a stable internal polymorphism of inspectors and noninspectors. While the equilibrial frequency of inspectors can be low (i.e. <10%) at large shoal size, the proportion of shoals containing any inspectors - and therefore exhibiting the inspection behavior - is much greater. Both models presented here, and N-person games in general are equivalent to intrademic group selection models of evolution in structured populations, in which shoals are trait groups and co-operation evolves by between-shoal selection. While the results are cast in terms of predator inspection, the model itself is general and applies to any multi-group scenario where co-operators benefit entire groups at their own expense. The results presented here add to the mounting theoretical and empirical evidence that co-operation is frequently not a pure evolutionarily stable strategy, and that many metapopulations should be polymorphic for both co-operators and defectors. Interactions/Payoffs/Population dynamics - ESS/Population structure/Biological applications/Simulation.
• 49. Dugatkin, Lee Alan and David Sloan Wilson. 1991. "Rover: A Strategy for Exploiting Cooperators in a Patchy Environment." American Naturalist 138:687-701.
  • [Dugatkin and Wilson] present a computer simulation that examines the dynamics of cooperative behavior in a patchy environment. A new defecting strategy called "ROVER" is introduced, which uses a rule analogous to the "marginal value" theorem to determine how long to stay in a patch. A wide range of parameter values allow ROVERs to invade a metapopulation of tit-for-tat strategists (TFT) and spread either to fixation or to a stable equilibrium in which ROVER is the majority strategy. [The] model, along with previous models that invoke different mechanisms, suggests that even guarded forms of cooperation such as TFT are often vulnerable to invasion and that a stable mixture of cooperators and exploiters might be common in nature. Choices/Payoffs - comparing different PD matrices/Population dynamics - ESS/Population structure - information requirements/Limited set of allowable rules - enumerated set/Theory/Simulation.
• 50. Evangelista, Matthew. 1990. "Cooperation Theory and Disarmament Negotiations in the 1950s." World Politics 42:502-528.
  • Evaluates theories of the sources of cooperation in international politics by looking at the 1955 case of U.S.-Soviet disarmament negotiations. The 1955 case is a specific instance of a more general question about why two sides fail to reach a cooperative outcome, even when both sides ostensibly agree on the terms. Evangelista briefly reviews theories of cooperation in PD situations and the case of Deadlock; both games have been used to characterize arms race situations. By examining the motivations of each side in the 1955 negotiations, Evangelista concludes that the situation resembled Deadlock and not the PD because only one side, the Soviets, was interested in the cooperative solution and saw the situation as a PD. The U.S. was not interested in disarming and thus did not view the situation as a PD. This illustrates Evangelista's argument about how a state's preferences may affect the type of game each plays. He concludes by drawing some parallels between 1955 and U.S.-Soviet negotiations in the late 1980s, and suggests that future work might try to link particular games to the "domestic political determinants of foreign policy" (p. 528). - abstract by LD Payoffs/Relative vs. absolute gains/Politics and law - international/Empirical.
• 51. Evangelista, Matthew. 1991. "Sources of Moderation in Soviet Security Policy." In Behavior, Society, and Nuclear War, vol. 2, edited by Philip E. Tetlock, Jo L. Husbands, Robert Jervis, Paul C. Stern, and Charles Tilly, pp. 254-354. Oxford: Oxford University Press.
  • Examines the basic question of the sources of change in Soviet security policy. Reviews academic and popular press theories of policy change, suggests the kinds of evidence that may be needed to test various theories, presents hypotheses for future work, and considers some promising methodological approaches. One of the seven academic theories discussed is cooperation theory, which draws heavily on Axelrod's presentation of TFT reciprocity. Evangelista notes that there may be problems with using the PD and TFT as models, particularly given the possibilities for misperception and the assumption of fixed preferences. He provides a substantial overview of evidence from the Soviet case, from Khrushchev through Gorbachev, that might be useful for testing some of these theories. The Limited Test Ban Treaty of 1963 is presented as an example where TFT and a PD model might explain changes in Soviet policy (pp. 296-302). Evangelista concludes by listing some hypotheses that might be tested empirically, using both comparative case studies and quantitative and statistical methods. - abstract by LD Payoffs/Politics and law - international
• 52. "Evo-Economics: Biology Meets the Dismal Science." 1994. Economist. 329:93-95.
  • Discussion of the emergence of evolutionary economics, grounded in the common interest of economics and evolution in the individual. Evolutionary economics blends the PD of economists (where individual self-interest leads to collective disaster) with the iterated PD of biologists (where cooperation may evolve in repeated play). TFT or reciprocal altruism may help economists to explain incidents of altruism and puzzles like the voter's paradox. However, even this explanation of altruism may be too narrow: TFT suggests that the payoffs or exchanges are in the same currency, but it may be that the payoffs are genetic, not economic. Beyond this, there are two primary differences between economics and evolutionists. Economists take consumption as an end in itself and take preferences as given. In contrast, evolutionists see consumption as a means to successful reproduction and develop theories to explain preferences. - abstract by LD Population structure - information requirements/Economics and business.
• 53. Farrell, Joseph and Roger Ware. 1989. "Evolutionary Stability in the Repeated Prisoner's Dilemma." Theoretical Population Biology 36:161-166.
  • Farrell and Ware suggest that future work might direct attention to mixtures of strategies and mutants that empirical observations suggest occur in the real world. - LD See also Louis Marinoff (1990) "The Inapplicability of Evolutionarily Stable Strategy to the Prisoner's Dilemma." Philosophy of Science 41:461-472. Recently, biologists have explored evolutionary explanations of apparently altruistic behavior in situations of conflict, often modeled as the "Prisoner's Dilemma." Certain simple cooperative strategies, notably TIT-FOR-TAT, have been successful in computer simulations of the evolution of populations of individuals who interact according to the Prisoner's Dilemma. Some attempts to formalize this have used the concept of "evolutionary stability." But Boyd and Lorberbaum (1987, Nature (London) 327, 58-59) recently showed that no single pure strategy (such as TIT-FOR-TAT) can be evolutionarily stable. [Farrell and Ware] extend [Boyd and Lorberbaum's] argument to derive a more powerful result, which implies, first, that no finite mixture of pure strategies can be evolutionarily stable, and, second, that no mixture of TIT-FOR-n-TATS can be evolutionarily stable. [Farrell and Ware] interpret [their] negative results to suggest that evolutionary stability is too demanding a criterion. Population dynamics - ESS/Theory/Deductive.
• 54. Fogel, David B. 1993. "Evolving Behaviors in the Iterated Prisoner's Dilemma." Evolutionary Computation 1:77-97.
  • Evolutionary programming experiments are conducted to investigate the conditions that promote the evolution of cooperative behavior in the iterated prisoner's dilemma. A population of logical stimulus-response devices is maintained over successive generations with selection based on individual fitness. The reward for selfish behavior is varied across a series of trials. Simulations indicate three distinct patterns of behaviors in which mutual cooperation in inevitable, improbable, or apparently random. The ultimate behavior can be reliably predicted by examining the payoff matrix that defines the reward for alternative joint behaviors. Payoffs - comparing different PD matrices/Population dynamics - ESS/Automata theory/Simulation.
• 55. "Forgiveness Math." 1993, May. Discover. 14:62-67.
  • Considers the question of how and why altruistic behavior came to exist in nature. Describes the PD and the importance of iteration to bringing about cooperative outcomes. Discusses the Axelrod tournaments and the success of Rapoport's TFT, and the result from Axelrod's simulations that TFT does best within a cluster of kin, but that it is also vulnerable to noise or errors. The author talks to Karl Sigmund about his simulation work with Martin Nowak. In a series of simulations with stochastic strategies, they found that including TFT in the population was important for ultimately bringing about a more cooperative population where Generous TFT (TFT, except when faced with defection by the other player, cooperate one out of every three times) was firmly established. Sigmund suggests that his future work will focus on trying to introduce longer memory into play to simulate the importance of trust in repeated interactions. - abstract by LD Population dynamics/Limited set of allowable rules/Theory/Miscellaneous.
• 56. Frank, Robert H. 1988. Passions within Reason: The Strategic Role of the Emotions. New York: W.W. Norton & Company.
  • Considers the class of commitment problems, one form of which is embodied in the PD. Commitment problems are ones in which "it is in a person's interest to make a binding commitment to behave in a way that will later seem contrary to self-interest," at least in the short run (p. 47). Frank says that materially self-interested or rational motives are important for understanding behavior, but that such models are ultimately inadequate for explaining behavior, and actions intended to maximize self-interest may fail to do so because the actors do not resolve their commitment problems. In Chapter 2, Frank notes the result from Axelrod that stable cooperation tends to emerge when there is a set of players who interact repeatedly and who are able to identify other cooperators. However, he suggests that Axelrod's work more closely parallels Darwinian individual selection as an explanation for the emergence of cooperation, and he turns to expanding upon Trivers's notion of the role of mediating emotions in engendering cooperation. Frank says that certain emotions, such as anger or guilt, which he calls moral sentiments, and the development of reputation, are mechanisms through which people can signal to others their willingness to cooperate in PD-like situations. Moral sentiments alter the material incentives that people face when making decisions, whereas reputation is a mechanism through which people can identify other cooperators. Neither mechanism is a perfect signal. Frank draws support for his arguments from various examples in the popular press, experimental data, and working through a formal version of the commitment model. - abstract by LD Interactions/Payoffs/Noise - misperception/Population structure - information requirements/Reputation/Economics and business/Sociology and anthropology/Psychology/Theory/Deductive/Empirical.
• 57. Frank, Robert. 1990. "A Theory of Moral Sentiments." In Beyond Self-Interest, edited by Jane J. Mansbridge, pp. 71-96. Chicago: University of Chicago Press.
  • Considers the question of how people keep commitments, and the incentives they have to fulfill promises. Frank says that specific emotions act as commitment devices. Some emotions, which he calls moral sentiments, compete with feelings that arise from rational calculations based upon material payoffs. These emotions, like guilt, alter people's incentives in ways such that people feel aversion to cheating, for example. Frank examines the role of moral sentiments in the context of the cheating problem in the PD, with attention to the importance of being able to recognize and to cooperate with other cooperators. Varying the cooperators' ability to recognize other cooperators, Frank suggests that the self-interested person might want to acquire moral sentiments, because such emotions can be used to help identify other potential cooperators. - abstract by LD Population structure - information requirements/Sociology and anthropology/Psychology/Theory/Deductive/Collateral research
• 58. Friedland, Nehemia. 1990. "Attribution of Control as a Determinant of Cooperation in Exchange Interactions." Journal of Applied Social Psychology 20:303-320.
  • Parties to conflict and to exchange interactions typically experience a considerable uncertainty as to the intentions and strategic plans of their adversaries. Such uncertainty is threatening and can therefore elicit competitive responses. Perceived control over an adversary's actions and over the course of an interaction can reduce uncertainty, lower the perceived risk of exploitation, and thus facilitate cooperative responses. This mediating role of perceived control was demonstrated in two experiments. They showed that certain patterns of change in one party's strategy enhanced the other party's perception of control and, concurrently, increased the frequency of its cooperative responses. A third experiment showed that variations in perceived control affect the tendency to cooperate, even if such variations are not directly related to or induced by the adversary's strategy. Psychology/Empirical.
• 59. Fudenberg, Drew and Eric Maskin. 1990. "Evolution and Cooperation in Noisy Repeated Games." American Economic Review 80:274-279.
  • Paper provides support for the intuition that efficient outcomes are more likely in repeated games. Repeated play in games like the PD can lead to cooperation, but there is a small chance that players in these games make mistakes, that their actions are not what they intended. Using an evolutionary simulation which randomly paired strategies against each other, and looking at symmetric two-player games (here, the PD and Battle of the Sexes), the authors found that if there is some small chance for misimplementation, evolution may weed out strategies that impose large penalties for deviations. If the penalties for deviation are not too drastic, then inefficient strategies can be invaded by efficient ones. If "there is a unique payoff pair that maximizes the sum of players' payoffs, then any ES (pure) strategy must be efficient. If there are multiple pairs that maximize the sum of the payoffs, then ES does not imply efficiency but still imposes restrictions on the set of equilibrium payoffs" (p. 275). Allowing only finitely complex strategies, they found that "any finitely complex ES strategy must give rise to the cooperative outcome in repeated games" (p. 278). If one allows infinitely complex strategies, then by the Folk Theorem ESS does not restrict possible payoffs. - abstract by LD Payoffs/Noise - misimplementation/Population dynamics - ESS/Population dynamics - replicator dynamics/Limited set of allowable rules - finite state machines/Theory/Simulation.
• 60. Getty, Thomas. 1987. "Dear Enemies and the Prisoner's Dilemma: Why Should Territorial Neighbors Form Defensive Coalitions?" American Zoology 27:327-336.
  • Game-theoretic arguments are used to derive two new hypotheses to explain why territorial residents so consistently defeat potential usurpers. Both hypotheses are based on help from established, familiar neighbors. The first hypothesis follows simply from Krebs' (1982) assertion that the value of a territory to a usurper must be decremented by the costs of negotiating dear-enemy relationships with the remaining neighbors. An implication is that the remaining neighbors will also have to pay these renegotiation costs if the usurper succeeds. The first hypothesis is that it may benefit a territorial animal to help its established neighbors defend so it can avoid having to renegotiate territorial boundaries with a new, unfamiliar neighbor. This hypothesis assumes net positive benefits for helping without requiring reciprocation. The second hypothesis requires reciprocation to compensate for immediate net costs of helping. An animal should help its neighbors fight off usurpers only if the neighbors will reciprocate. This hypothesis is based on the prisoner's dilemma game and builds on Axelrod's (1984) work. Cooperative defense (reciprocal help) can be an evolutionarily stable strategy (ESS) if several conditions are met. One critical condition is that the relationship between neighbors is relatively stable. Cooperative defense should help established neighbors retain their territories, and should therefore be a cause, as well as a consequence of stability. It is suggested that the necessary conditions are not very restrictive, that they are often met in nature, and that shared defense is observed but not recognized as such. Interactions/Population dynamics - ESS/Population structure - spatial models/Biological applications.
• 61. Glance, Natalie S. and Bernardo A. Huberman. 1994, March. "The Dynamics of Social Dilemmas." Scientific American 270:76-81.
  • Discussion of how to achieve cooperation in groups of various sizes in the context of an n-person PD game. Past work suggests that cooperation is more likely in smaller groups than in larger ones, and there is greater cooperation when players are allowed more communication with each other. Using computer simulations of the social behavior of groups drawn from theories from statistical thermodynamics, the authors examined the dynamics and the outcomes of group interactions. They found that there were two stable points in large groups: either there was a great deal or very little cooperation, with small fluctuations around these stable points, due to uncertainty within the group about the length of the game and about the effect of individual contributions on the group. Large random fluctuations were related to group size, which explained why the behavior of groups tended to be stable over time, but when it did change, why it changed quickly. The authors also considered the effects of introducing greater group diversity, and the evolution of cooperation in hierarchies. - abstract by LD Interactions/Payoffs/Population structure/Population size/Simulation.
• 62. Godfray, H.C.J. 1992. "The Evolution of Forgiveness." Nature 355:206-207.
  • Although repeated interactions may lead to reciprocal altruism, how does one account for the spread of such behavior in non-altruistic populations. In a PD, what is an individual's best response, based on previous interactions with the other animal? One solution, TFT, was proposed through Axelrod's work and tournaments, but this solution does not account for things like recognition errors. Another possible solution is Generous TFT (GTFT). GTFT responds to past cooperation with cooperation, but forgives defection on a certain proportion of the other player's defections. If the proportion of forgiveness is one-third, GTFT cannot be invaded by other GTFTs with different probabilities of forgiveness. Godfray considered whether GTFT could invade other populations by running a simulation. Against a population of Always Defect, GTFT cannot invade. However, if a population of Always Defect is first invaded by TFT, then GTFT can invade TFT. Godfray notes three implications for reciprocal altruism in nature. First, natural selection may favor simple rules, such as GTFT. Second, these rules are probabilistic and likely to be more forgiving than TFT. Finally, reciprocation strategies may invade more easily if there is an initial high probability of interactions between relatives. - abstract by LD Population dynamics - ESS/Population structure - clustering/Biological applications/Simulation.
• 63. Goldstein, Joshua S. 1991. "Reciprocity in Superpower Relations: An Empirical Analysis." International Studies Quarterly 35:195-209.
  • Past empirical studies of superpower reciprocity have produced inconsistent results that may be traced to several recurrent methodological problems. Correcting these problems, [Goldstein] analyzed statistically the responses of the United States and the Soviet Union to each other's actions over the past forty years. Results were replicated across quasi-experiments using different data sources, time periods, and model specifications. Both superpowers reciprocate each other's actions within a short time frame of up to about two months. Neither responds inversely (for example, by becoming more cooperative following hostile actions by the other). In the 1950s and 1960s U.S. reciprocity following Soviet actions was much more consistent than Soviet reciprocity following U.S. actions, but in the 1970s and 1980s Soviet reciprocity was more consistent than U.S. reciprocity. Noise/Politics and law - international/Empirical.
• 64. Goldstein, Joshua S. and John R. Freeman. 1990. Three-Way Street: Strategic Reciprocity in World Politics. Chicago: University of Chicago Press.
  • Discussion of cooperation and the relationship among the United States, the Soviet Union, and China. Using theories drawn from game theory and psychology in conjunction with data analysis and case studies, Goldstein and Freeman find a norm of bilateral reciprocity, and that cooperative acts elicit cooperation. However, hostile initiatives used to bring about cooperation usually fail, instead drawing hostile responses. Chapter 1 describes and critiques different theories of cooperation from game theory, psychology, and quantitative-empirical theory. The discussion of game theoretic approaches to cooperation draws heavily and extensively on Axelrod's work and the success of TFT. The authors draw four cooperative-reciprocal strategies from these theories to test against the data: TFT and three versions of GRIT (Graduated Reciprocation In Tension-reduction) from psychological theories. Chapter 2 sketches relationships among the three powers from 1948 through 1987; Chapter 3 provides the results of data analysis. Chapter 4 presents six case studies of cooperative initiatives. Chapter 5 evaluates the different cooperative-reciprocal strategies based on the evidence and simulation results. TFT was the least effective strategy, although the cooperative effects of all four of the strategies die out. Goldstein and Freeman suggest that this may be due to two-way reciprocity, and that one country's willingness to initiate cooperation may not be enough to promote cooperation among all three countries. The situation might better be seen as three linked dyadic games, rather than a three-person game, or a three-person game with payoffs such that triangular asymmetry makes sense for two of the players. Game theory has little to say about the latter situation, although rational expectations theory with Bayesian players in sequential games may be useful to explore in the future. - abstract by LD Interactions/Payoffs/Limited set of allowable rules - enumerated set/Politics and law - international/Empirical/Simulation.
• 65. Grieco, Joseph M. 1988. "Anarchy and the Limits of Cooperation: A Realist Critique of the Newest Liberal Institutionalism." International Organization 42:485-507.
  • The author provides a summary table of key differences between the theories he discusses on page 503. - LD Considers major theories in international relations, realism and liberal institutionalism. Neoliberal institutionalism is the most recent form of liberal institutionalism. Grieco hopes to show that "neoliberal institutionalism misconstrues the realist analysis of international anarchy and therefore it misunderstands the realist analysis of the impact of anarchy on the preferences and actions of states" (p. 487). Realists believe that anarchy in the international system leads to conflict, and that institutions are not capable of mitigating the effects of anarchy to bring about cooperation. Neoliberal institutionalists believe realists overstate the conflict within the system and the inability of institutions to engender cooperation. They suggest that there are countervailing forces, such as repeated interactions, pushing toward cooperation. Proponents of this theory are concerned with cheating as the major threat to cooperation; anarchy means that there is no organization to enforce rules against cheating. They identify the state's goal as to attain the greatest possible individual or absolute gain. Realists reject the concern with cheating; anarchy in the international system means that there is no way to prevent one state from using violence against another. Thus, realists believe that the state's goal is to ensure its survival and to worry about relative, not absolute, gains. Grieco concludes by suggesting that future work needs to conduct empirical tests of these two theories and briefly considers possible cases that might be used. - abstract by LD Politics and law - international/Relative vs. absolute gains.
• 66. Grieco, Joseph M. 1990. Cooperation among Nations: Europe, America, and Non-tariff Barriers to Trade. Ithaca, NY: Cornell University Press.
  • Explores the question of how and why states are willing to cooperate with each other given the constraints of anarchy. Grieco considers two competing theories of international relations, realism and neoliberal institutionalism, to determine which best explains the problem of international cooperation. In the first two chapters, he examines the logic of each theory and derives competing testable hypotheses from each. Chapters 3 through 7 are devoted to applying the two theories to explaining the case of the Toyko Round regime for the reduction of non-tariff barriers to trade. In the concluding chapter Grieco argues that realism is superior to neoliberal institutionalism in terms of its logic - the concerns with cheating and the gaps in relative gains - and its ability to explain political events. He suggests that future work should consider testing other core competing hypotheses from the two theories, such as the role of the shadow of the future and the partners states prefer in cooperative agreements. - abstract by LD Payoffs/Relative vs. absolute gains/Politics and law - international/Empirical.
• 67. Grieco, Joseph M. 1988. "Realist Theory and the Problem of International Cooperation: Analysis with an Amended Prisoner's Dilemma Model." Journal of Politics 50:600-624.
  • Realist political theory finds that states are positional in character. Thus, states prefer that relative achievements of jointly produced gains not advantage partners, and their concerns about relative gains may constrain their willingness to cooperate. Conventional presentations of the game of Prisoner's Dilemma do not depict Realism's specification of the relative gains element of the structure of state preferences or Realism's analysis of the capacity of state concerns about relative gains to impede cooperation. However, by distinguishing between game payoffs and state utility, an Amended Prisoner's Dilemma model can depict both the relative-gains element of state preferences and the relative-gains problem for cooperation. This Amended Prisoner's Dilemma facilitates analysis of an important systemic constraint on international cooperation identified by Realist political theory, contributes to our understanding of international institutions, and draws our attention to a number of potentially interesting research problems concerning international collaboration. Payoffs/Payoffs - comparing different PD matrices/Politics and law - international/Relative vs. absolute gains.
• 68. Hanson, David P. 1991. "Managing for Ethics: Some Implications of Research on the Prisoner's Dilemma Game." SAM Advanced Management Journal 56:16-20.
  • Considers the question of how managers can promote ethical conduct, behavior for the long-term good of the company, by applying some of the results from analyses of the PD. Drawing on Rapoport's and Axelrod's work, Hanson suggests that there are three conditions which make the PD more like reality and which promote cooperative or ethical outcomes: attention to the larger game and the actions of players other than one's partner; iteration; and retaliation against past defections. Under these conditions, Rapoport and Axelrod both found that TFT strategies were successful. Hanson notes that companies must face two levels of ethical decision making: within the industry marketplace, and within the company itself. Each firm has more control over the incentives for internal ethical decision making than it does over those in the marketplace. He considers the cases of pollution, defense contracting, and accounting. Legislation has effectively imposed the three Axelrod/Rapoport conditions in the case of pollution, but the incentives for the defense and accounting industries do not meet the three conditions for ethics in the marketplace. Hanson suggests that to meet the Axelrod/Rapoport conditions within the company, managers need to groom several applicants for each position so that no individual is indispensable (larger game), evaluate employees' long-term performances (iteration), and do not grant pardon for past misdeeds (retaliation for past defections). - abstract by LD Economics and business.
• 69. Harcourt, Alexander H. 1992. "Cooperation in Conflicts: Commonalities between Humans and Other Animals." Politics and the Life Sciences 11:251-259.
  • Examines similarities in the ways that humans and other animals cooperate in conflict situations. Harcourt argues that animal societies may be simpler analogues of human systems. He considers four questions: how does cooperation evolve and how is it maintained; when should a player ally with others; who are the best or preferred partners; and what is the influence of society on coalitions, and vice versa. Axelrod's work is used to describe how reciprocal altruism or TFT might explain the spread and maintenance of cooperation within a population. Harcourt draws on a number of zoological studies to support his arguments, and he concludes by noting that political science and zoology might learn a great deal from the other's work. - abstract by LD Biological applications/Population structure/Politics and law - domestic/Politics and law - international/Sociology and anthropology.
• 70. Harpending, Henry C. and Jay Sobus. 1987. "Sociopathy as an Adaptation." Ethology and Sociobiology 8:63S-72S.
  • Sociopathy in males and hysteria (Briquet's syndrome) in females very closely fit predictions from a model of characteristics of cheaters or nonreciprocators in a complex social system. Such a model is discussed and characteristics of sociopaths and hysterics are described. Since a successful cheating adaptation should require, above all else, concealment of the trait, recognition and diagnosis of these traits in humans will always be difficult and ambiguous at the level of language and interpersonal interaction. Population structure - information requirements/Limited set of allowable rules - limited rationality/Sociology and anthropology.
• 71. Harrington, John C. and Robert Axelrod. 1994. "Evolutionary Stability in the Iterated Prisoner's Dilemma with Noise." Under submission .
  • Argues that in a PD with noise due to misimplementation, pure ESSs, contrite TFT (CTFT) and Pavolv (win-stay, lose-shift), can exist, depending upon the discount rate and the payoffs. However, in a PD with noise due to misperception, there is no ESS. When the noise is a result of misimplementation, there is agreement between the players about what happened, so the players may be able to restore cooperation. When the noise is due to misperception, there is no agreement about what happened, so it may be more difficult to restore cooepraiton; Harrington and Axelrod suggest that future research should explore the restoration of cooperation with misperception. They conclude by noting that in order to understand the kinds of strategies that will evolve in a PD, it is important to know about the payoffs, the discount rate, and the type of noise. - abstract by LD Payoffs/Noise - misimplementation/Noise - misperception/Population dynamics - ESS/Limited set of allowable rules - enumerated set/Theory/Deductive.
• 72. Hart, Benjamin L. and Lynette A. Hart. 1992. "Reciprocal Allogrooming in Impala, Aepyceros melampus." Animal Behaviour 44:1073-83.
  • Adult female and male impala engage in a type of allogrooming in which partners alternately deliver bouts of oral grooming to the head and neck. These grooming encounters comprise typically six to 12 tit-for-tat-like exchanges of bouts and are highly reciprocal among adult females, adult bachelor males and subadult males. Although allogrooming among females could be between related individuals, that occurring among adult males would appear to be between unrelated individuals. Unlike allogrooming reported for some primate species and other ungulates, the dominant impala received no more grooming than the subordinate. It is proposed that one function of impala allogrooming is to reduce the ectoparasite load on body areas an animal cannot reach with its own mouth. The impala reciprocal allogrooming system is unique among free-ranging antelope and other ungulates and may be a candidate for the tit-for-tat strategy of evolved cooperation. Population dynamics - ESS/Biological applications/Biological applications - specific species - impala.
• 73. Hart, Lynette A. and Benjamin L. Hart. 1988. "Autogrooming and Social Grooming in Impala." Annals of the New York Academy of Sciences 525:399-402.
  • Compared the personal and social grooming habits of impala, Grant's gazelle, and common wildebeest. None of these animals can fully groom themselves, but because impala largely live in deciduous woodland areas, reciprocal social grooming should be particularly important for the removal of ticks. Observing female herds of the animals, the authors found that impala exhibited social oral grooming, whereas the gazelle and wildebeest did not. They suggest that reciprocal social grooming is a form of reciprocal altruism, not kin selection, since the females in these herds are unrelated. - abstract by LD Biological applications/Biological applications - specific species - impala/Collateral research.
• 74. Hauser, Marc D. 1992. "Costs of Deception: Cheaters Are Punished in Rhesus Monkeys (Macaca mulatta)." Proceedings of the National Academy of Sciences, USA 89:12137-12139.
  • From a functional perspective, deception can evolve in animal populations but should be constrained by the costs associated with detection. It then follows that withholding information should be more prevalent as a form of deception than active falsification of information because of the relative difficulties associated with detecting cheaters. Empirical studies of deception have focused on the benefits of cheating but have provided no data on the costs associated with being detected as a cheater. [Hauser] present[s] results from field experiments on rhesus monkeys (Macaca mulatta) which show that individuals discovering food announce their discoveries by calling on 45% of all trials. Discoverers who failed to call, but were detected with food by other group members, received significantly more aggression than vocal discoverers. Moreover, silent female discoverers ate significantly less food than vocal females. This demonstrates that there are significant costs to withholding information. Such costs may constrain the frequency with which deception occurs in this and other populations. Payoffs/Biological applications/Sociology and anthropology/Biological applications - specific species - rhesus monkeys.
• 75. Hemelrijk, C.K. 1991. "Interchange of 'Altruistic' Acts as an Epiphenomenon." Journal of Theoretical Biology 153:131-139.
  • Corrects error in 1990 article published in the same journal.- LD Draws a distinction between reciprocity (one kind of act exchanged for an act of the same kind) and interchange (barter of different kinds of acts). Studies reciprocity and interchange "among all pairs of groupmembers (i.e. at group level) as a correlation between an actor and a receiver matrix" (p. 137). Hemelrijk re-analyzed Seyfarth's (1980) data on wild female vervets. As a supplement to the correlation between grooming and received support discussed in her 1990 paper, she found that the reverse correlation between support and being groomed was also significant. However, the latter correlation could be explained as a side-effect of: 1) reciprocity in grooming and a relationship between the frequency of grooming and support; and 2) reciprocity of support and a correlation between received grooming and received support. This result is at odds with the interchange of support for being groomed suggested by Seyfarth and Cheney (1984). Interactions/Population structure/Biological applications/Biological applications - specific species - vervets.
• 76. Hemelrijk, C.K. 1990. "A Matrix Partial Correlation Test Used in Investigations of Reciprocity and Other Social Interaction Patterns at Group Level." Journal of Theoretical Biology 143:405-420.
  • Reciprocity and other social interaction patterns can be studied at two levels, within pairs (i.e. at dyadic level) and among pairs (i.e. at group level). In this paper advantages of the latter approach are emphasized. However, an analysis at group level implies the correlation of interaction matrices and because such data are statistically dependent, the significance of a correlation has to be calculated in a special way. This is done by means of Mantel's permutation procedure. In order to reckon with individual variation, Mantel's permutation procedure is used in combination with the so-called Kr statistic, whereby correlations are calculated simultaneously for each separate row. With the aid of the Kr test, the correlation for interchange of grooming for the receipt of "support" in conflicts in baboons and vervet monkeys [data from Seyfarth (1976, Anim. Behav. 24, 917-938, 1980, Anim. Behav. 28, 798-813)] was reconfirmed. However, this result may have arisen as a by-product of correlations with other variables. Therefore, the partial form of the Kr test is derived and applied to Seyfarth's data and it appears that the interchange of grooming for the receipt of "support" in conflicts, is indeed a spurious correlation in vervets but not in baboons. Direct tuning of grooming to the amount of received "support" thus seems therefore unlikely in case of the vervets, but may exist in the baboons. Some further suggestions are given about the way in which reciprocity/interchange may emerge as a by-product of simple (behavioural) rules. In certain behaviours (like for instance "reconciliation") missing values occur "conditionally", i.e. when the preceding behaviour (a fight in case of "reconciliation") was absent. The same Kr partial correlation test can be used in order to make efficient use of the existing data. This is illustrated with an example of a test for reciprocity of "tolerance" during food sharing among captive female chimpanzees. Interactions/Biological applications/Biological applications - specific species - chimpanzees.
• 77. Hemelrijk, Charlotte K. 1990. "Models of, and Tests for, Reciprocity, Unidirectionality and Other Social Interaction Patterns at a Group Level." Animal Behaviour 39:1013-1029.
  • Research on reciprocity is impaired by confusing definitions and often wrongly used statistical tests. Here, two models of the mechanism on which reciprocity is based are discussed and an initial step towards a new framework for its analysis is presented. A distinction is made between reciprocity and interchange. In the case of reciprocity, for one kind of act the same kind is received in return. In interchange, however, two different kinds of acts are bartered. Three types of reciprocity/interchange in social actions among all pairs of group-members are distinguished ('qualitative', 'relative' and 'absolute') on the basis of the precision of the reciprocity/interchange. Permutation procedures for association between matrices (such as the Mantel Z and two other newly derived tests) are used as a statistical test for detecting reciprocity/interchange. A rough comparison of the power of the two new tests is included. The tests can be applied to all kinds of group-living animals and to all sorts of social behaviour. The distinction between the three types of reciprocity/interchange and the matching statistical methods are also useful for defining and detecting other patterns in social interactions, like unidirectionality and associations between different kinds of social behaviour. The influence on social interactions of variables like dominance rank, age and sex can be analysed in the three forms by testing correlations between invented matrices which represent the influence of these variables (the so-called hypothesis matrices) and social interaction matrices. These methods are extended for two categories of individuals, thus allowing the investigation of, for example, reciprocity between males and females. The methods are illustrated with examples of coalition formation and grooming behaviour among captive chimpanzees, Pan troglodytes. Interactions/Biological applications/Biological applications - specific species - chimpanzees.
• 78. Hill, Greg. 1993, January. "From Stagnation to Recovery: A Prisoner's Dilemma and Its Solution." Challenge 36:61-62.
  • Looks at the question of cyclical periods of economic stagnation. Hill suggests that the investment decisions of firms in such a situation resemble a PD: firms are less willing to risk investment individually, although each firm would probably benefit from increased sales if other firms invested. Since it is in each firm's interest not to invest in the short run, no firms invest and the economy remains stagnant, so how does economic recovery ever begin? The neoclassical answer to this question is that interest rates fall in the stagnant period and individual firms then find it worthwhile to invest. The Keynesian answer to this question is that government invests first and thereby reduces the risk individual firms face. Hill notes that these solutions do not always work, and suggests a third possibility: government should reduce the length of economic stagnation by negotiating a solution or contract among firms in which all agree to invest simultaneously. - abstract by LD Economics and business.
• 79. Hirshleifer, David and Eric Rasmusen. 1989. "Cooperation in a Repeated Prisoners' Dilemma with Ostracism." Journal of Economic Behavior and Organization 12:87-106.
  • The unique Nash equilibrium of the finitely repeated n-person Prisoners' Dilemma calls for defection in all rounds. One way to enforce cooperation in groups is ostracism: players who defect are expelled. If the group's members prefer not to diminish its size, ostracism hurts the legitimate members of the group as well as the outcast, putting the credibility of the threat in doubt. Nonetheless, [the authors] show that ostracism can be effective in promoting cooperation with either finite or infinite rounds of play. The model can be applied to games other than the Prisoners' Dilemma, and ostracism can enforce inefficient as well as efficient outcomes. Interactions/Payoffs/Payoffs - comparing different PD matrices/Endogenous ending - ostracism/Population size/Population structure - information requirements/Norms/Economics and business/Sociology and anthropology/Deductive/Theory.
• 80. Hirshleifer, Jack and Juan Carlos Martinez Coll. 1992. "Selection, Mutation and the Preservation of Diversity in Evolutionary Games." Revista Espanola de Economia 9:251-273.
  • Evolutionary models suggesting that in mixed-motive situations only a single strategy, or only a single type of behavior, will ultimately prevail cannot be regarded as satisfactory. Among the forces supporting diversity of strategies and of behaviours are: (i) multiple and/or mixed evolutionary equilibria, (ii) mutation pressure, and (iii) transient dynamic processes. This paper studies the interaction of the archetype strategies COOPERATE versus DEFECT in Prisoners' Dilemma, and COWARD versus DAREDEVIL in Chicken, with two alternative reactive strategies TIT FOR TAT and BULLY. Only in exceptional limiting cases does a single strategy or a single form of behavior come to extinguish all others. TIT FOR TAT tends to support the predominance of nice behaviors in Prisoners' Dilemma (but not Chicken), while BULLY tends to support a predominance of mean behaviors generally. Payoffs/Payoffs - comparing different PD matrices/Population dynamics/Limited set of allowable rules - enumerated set/Theory/Simulation.
• 81. Huberman, Bernardo A. and Natalie S. Glance. 1993. "Evolutionary Games and Computer Simulations." Proceedings of the National Academy of Sciences, USA 90:7716-7718.
  • Huberman and Glance found greater cooperation between players with greater delays in updating information. - LD For other work on asynchronous choices, see H.A. Ceccatto and B.A. Huberman (1989) "Persistence of Nonoptimal Strategies." PNAS, USA 86:3443-3446. The Prisoner's Dilemma has long been considered the paradigm for studying the emergence of cooperation among selfish individuals. Because of its importance, it has been studied through computer experiments as well as in the laboratory and by analytical means. However, there are important differences between the way a system composed of many interacting elements is simulated by a digital machine and the manner in which it behaves when studied in real experiments. In some instances, these disparities can be marked enough so as to cast doubt on the implications of cellular automata-type simulations for the study of cooperation in social systems. In particular, if such a simulation imposes space-time granularity, then its ability to describe the real world may be compromised. Indeed, [Huberman and Glance] show that the results of digital simulations regarding territoriality and cooperation differ greatly when time is discrete as opposed to continuous. Population dynamics/Population structure - spatial models/Limited set of allowable rules - finite state machines/Automata theory/Simulation.
• 82. Hughes, Kirsty and Christine Oughton. 1993. "Diversification, Multi-market Contact and Profitability." Economica 60:203-224.
  • This paper analyses the relationships between diversification, multi-market contact and industry profitability. It focuses on the link between diversification and multi-market contact to show that, when diversification establishes or increases the extent to which firms meet in more than one market, the effect of such multi-market contact is to increase the possibility that collusion emerges as an evolutionarily stable strategy. As a result, multi-market contact may increase the potential for tacit collusion and so lead to higher profitability. The effects of diversification and multi-market contact on the price-cost margin and the rate of return to capital are estimated using a specially constructed new database for UK manufacturing industry in 1979. This database provides information on the diversification and multi-market contact of 418 firms across 134 manufacturing industries, thus linking firm- and industry-level data. The results show a clear positive effect of multi-market contact on industry profitability. Economics and business/Deductive/Empirical.
• 83. Ickes, Barry W. and Larry Samuelson. 1987. "Job Transfers and Incentives in Complex Organizations: Thwarting the Ratchet Effect." RAND Journal of Economics 18:275-286.
  • Many complex organizations, such as planned Soviet enterprises and the U.S. military, routinely transfer employees between jobs. Since this sacrifices job-specific human capital, the practice is puzzling. This article shows that regular job transfers may be part of an optimal incentive scheme in organizations plagued by the ratchet effect. The ratchet effect arises when an employer is uncertain as to the productivity of the various positions or jobs within an organization. Workers in highly productive jobs then have an incentive to disguise the productivity of their jobs by expending low effort and producing low output. This avoids having the employer construct more demanding renumeration schemes once the high productivity of a job becomes known. Job transfers break the link between current performance and future incentive schemes, and hence remove the incentive-stifling implications of the ratchet effect. This article examines the tradeoff between providing more effective incentives via job transfers and the accompanying sacrifice of job-specific human capital, establishes conditions under which job transfers are optimal, and develops comparative static results. Payoffs/Limited set of allowable rules - limited rationality/Economics and business/Deductive/Collateral research.
• 84. Ikegami, Takashi and Kunihiko Kaneko. 1990. "Computer Symbiosis - Emergence of Symbiotic Behavior through Evolution." Physica D 42:235-243.
  • Symbiosis is cooperation between distinct species. It is one of the most effective evolutionary processes, but its dynamics are not well understood as yet. A simple model of symbiosis is introduced, in which [the authors] consider interactions between hosts and parasites and also mutations of hosts and parasites. The interactions and mutations form a dynamical system on the populations of hosts and parasites. It is found that a symbiotic state is not static, but dynamically oscillates. Harmful parasites violating symbiosis appear periodically, but are rapidly extinguished by hosts and other parasites, and the symbiotic state is recovered. The relation between these phenomena and "TIT for TAT" strategy to maintain symbiosis is discussed. Population dynamics/Biological applications/Theory/Simulation.
• 85. Insko, Chester A., John Schopler, Stephen M. Drigotas, Kenneth A. Graetz, James Kennedy, Chante Cox and Garry Bornstein. 1993. "The Role of Communication in Interindividual-Intergroup Discontinuity." Journal of Conflict Resolution 37:108-138.
  • The present research was designed to explore the role of communication on interindividual-intergroup discontinuity in the context of the PDG-Alt matrix. (The PDG-Alt matrix is a prisoner's dilemma game matrix that adds a third withdrawal choice to the usual cooperative and uncooperative choices of the PDG matrix, and interindividual-intergroup discontinuity is the tendency of intergroup relations to be more competitive and less cooperative than interindividual relations.) Several predictions implied by the fear and greed explanations of interindividual-intergroup discontinuity were tested. One prediction, an implication of the fear hypothesis, is that communication should produce a larger increase in the cooperation of individuals than of groups. This prediction is based partially on the assumption that the outgroup schema, which leads to more fear of groups than of individuals, should reduce the credibility of between group communication. Given, however, that without communication individuals may not cooperate, what will they do? Will they withdraw or will they compete? Another prediction, an implication of the greed hypothesis, is that the absence of communication should result in a greater increase in withdrawal for individuals than for groups. This prediction is based partially on the assumption that the social support provided to fellow group members for self-interested competitiveness is absent for individuals. These predictions were confirmed. It was argued that the lesser tendency of individuals to cooperate when there is no communication with the opponent may explain partially the differing results of past discontinuity research (which has involved communication) and research reported in the PDG literature (which typically has not involved communication). Choices/Endogenous ending - voluntary exit/Population size/Sociology and anthropology/Psychology.
• 86. Irons, William. 1991. "How Did Morality Evolve?" Zygon 26:49-89.
  • This paper presents and criticizes Alexander's evolutionary theory of morality (1987). Earlier research, on which Alexander's theory is based, is also reviewed. The propensity to create moral systems evolved because it allowed ancestral humans to limit conflict within cooperating groups and thus form larger groups, which were advantageous because of intense between-group competition. Alexander sees moral codes as contractual, and the primary criticism of his theory is that moral codes are not completely contractual but also coercive. Ways of evaluating Alexander's theory as well as modified versions of it are discussed. Norms/Reputation/Sociology and anthropology.
• 87. Jablonowski, Mark. 1986. "Does Workable Competition Exist in the Property/Casualty Industry?" CPCU Journal 39:248-251.
  • Perfectly competitive markets yield social welfare benefits, but perfect markets are rare among modern American industries. However, social welfare benefits can exist when markets are workably competitive. Workable competition yields social benefits, but in such markets there is no clear means through which public policy actions would result in social benefit gains rather than losses. Jablonowski considers the case of the property and casualty insurance industry, important because of its size and the potential for costly disasters. Earnings in the insurance industry follow a pattern known as the underwriting cycle. The logic of this cycle parallels that of the PD. High earnings represent cooperative behavior among firms charging high prices. Declines in earnings are associated with price wars or defections of firms from charging a higher price. The earnings cycle suggests that a severe price instability exists in the market, independent of changes in market demand or costs of production. Jablonowski concludes that public policy action to correct for the price instability and to realize higher social benefits is problematic. It is not clear what incentives would be needed to induce firms to sacrifice potentially high but short term earnings. - abstract by LD Economics and business.
• 88. Jablonowski, Mark. 1988. "A Game-Theoretic Analysis of Insurer Behavior." CPCU Journal 41:117-121.
  • Game theory is an effective tool for analyzing the behavior of interdependent firms because it recognizes that one firm's outcome depends on the choices other players make. The property and casualty insurance industry might be described as a loose oligopoly, so one might expect some interdependence to have developed among firms. Jablonowski suggests that the PD may represent that fundamental characteristics of an oligopoly; if oligopolies want to achieve cooperation in repeated play, they need to police against the defections of other players. He briefly discusses extending the game to n players and methods of analyzing complex games. He concludes by noting that few detailed game theoretic analyses of industries exist, in part because business people will not discuss market strategies openly. - abstract by LD Interactions/Economics and business.
• 89. Jablonowski, Mark. 1987, July. "Insurance and Game Theory." Best's Review: Property/Casualty Insurance Edition 88:38-40.
  • Argues that game theory may be more useful than Adam Smith's theory of the invisible hand for understanding the behavior of interdependent firms. He uses a PD to illustrate a simple market where two firms have the choice to price high (cooperate) or low (defect). He argues that repeated play does not solve the dilemma, since the possibility of double crossing the other player always exists. He uses the PD example to provide a possible explanation for the underwriting cycle in the insurance industry. Firms want to cooperate and charge the high price, but some firms will defect. Eventually the non-defectors discover this, and they reduce their prices and maintain these lower rates for a while in order to encourage defectors to return to a higher pricing strategy. While the PD provides a plausible explanation, Jablonowski argues that the industry does not know enough about insurance companies' choices and goals to exploit game theory fully. - abstract by LD Economics and business.
• 90. James, Patrick and Frank Harvey. 1992. "The Most Dangerous Game: Superpower Rivalry in International Crises, 1948-1985." Journal of Politics 54:25-53.
  • Crises involving the superpowers as adversaries pose a serious threat to the survival of the global system. The present investigation will focus on patterns of response when one superpower is faced with a crisis resulting from a threat attributed to the other. The objective is to determine which among several strategic options characterizes superpower reactions. With that priority in mind, there will be four stages to the inquiry. First, several models for transforming conflict into cooperation will be presented in abstract terms. The second task is to operationalize these models with an emphasis on identifying strategic options that might be pursued in superpower crises. Third, data from the International Crisis Behavior Project will be used to test the predictive power and general relevance of the strategic options derived from the models. Fourth, and finally, the significance of the results and directions for further research will be discussed. Payoffs/Payoffs - comparing different PD matrices/Limited set of allowable rules - enumerated set/Limited set of allowable rules - limited rationality/Politics and law - international/Deductive/Empirical.
• 91. Joshi, N.V. 1987. "Evolution of Cooperation by Reciprocation within Structured Demes." Journal of Genetics 66:69-84.
  • The iterative two-person Prisoners' Dilemma game has been generalised to the N-person case. The evolution of cooperation is explored by matching the Tit For Tat (TFT) strategy (Axelrod and Hamilton 1981) against the selfish strategy. Extension of TFT to N-person situations yields a graded set of strategies from the softest TFT, which continues cooperation even if only one of the opponents reciprocates it, to the hardest, which would do so only when all the remaining opponents cooperate. The hardest TFT can go to fixation against the selfish strategy provided it crosses a threshold frequency pc. All the other TFT are invadable by the selfish (D) or the pure defector strategy, while none can invade D. Yet, provided a threshold pc is crossed, they can coexist stably with D. As N, the size of the group increases, the threshold pc also increases, indicating that the evolution of cooperation is more difficult for larger groups. Under certain conditions, only the soft TFT can coexist stably against the selfish strategy D, while the harder ones cannot. An interesting possibility of a complete takeover of the selfish population by successive invasions by harder and harder TFT strategies is also presented. Interactions/Payoffs - comparing different PD matrices/Population dynamics - ESS/Population dynamics - replicator dynamics/Population size/Limited set of allowable rules - enumerated set/Theory/Deductive.
• 92. Kahn, Lawrence M. and J. Keith Murnighan. 1993. "Conjecture, Uncertainty, and Cooperation in Prisoner's Dilemma Games." Journal of Economic Behavior and Organization 22:91-117.
  • This paper presents experimental tests of two models of cooperation in finitely-repeated prisoner's dilemma games (Kreps, Milgrom, Roberts, and Wilson, 1982). The models suggest that either a perception that the other party may use the tit-for-tat strategy or mutual uncertainty concerning dominant noncooperative strategies can lead to rational cooperation. The experiment independently manipulated both types of uncertainty and allowed for inferences concerning the players' prior, 'homemade' preferences for cooperation. Only in relatively restricted situations did either type of uncertainty promote cooperation. Instead, players cooperated much more than was predicted; they also cooperated more when they were certain of their opponents' payoffs. Payoffs - comparing different PD matrices/Limited set of allowable rules - limited rationality/Psychology/Empirical.
• 93. Kalai, Ehud and William Stanford. 1988. "Finite Rationality and Interpersonal Complexity in Repeated Games." Econometrica 56:397-410.
  • A measure of complexity for repeated game strategies is studied. This measure facilitates the investigation of some issues regarding finite rationality and the structure of subgame perfect equilibria of repeated games with discounting. Specifically, the complexity of a strategy in a given repeated game is defined to be the cardinality of the induced strategy set, i.e., the number of distinct strategies induced by the original strategy in all possible subgames. [The authors] observe that this cardinality is equal to the size (cardinality of the state set) of the smallest automaton which can implement the strategy. Thus, in a sense, complexity is measured on the basis of the amount of computing power inherent in the strategy. A measure of strategic memory is also studied. The following results are obtained: (1) combining two notions of bounded rationality (epsilon equilibrium and finite complexity), [the authors] find that every subgame perfect equilibrium of the repeated game can be approximated (with regard to payoffs) by a subgame perfect epsilon equilibrium of finite complexity. (2) For a generic class of normal form stage games, at every discount robust subgame perfect (DRSP) equilibrium, there are necessary relationships among the complexities and memories of the players' strategies. In the two player case, strategies must by equally complex and must have equal memories. (3) For a second class of two player stage games, [the authors] show that the payoff vectors for all DRSP equilibria are obtainable via equilibria in which the players' strategies are equally complex and have equal memories. Interactions/Limited set of allowable rules - finite state machines/Limited set of allowable rules - limited rationality/Theory/Automata theory/Deductive.
• 94. Keohane, Robert O. 1990. "Empathy and International Regimes." In Beyond Self-Interest, edited by Jane J. Mansbridge, pp. 227-236. Chicago: University of Chicago Press.
  • Examines the difficulty in distinguishing between egoism and altruism in international relations. In order to do so, there needs to be some decision about how people and organizations define self-interest - how they see their interests relative to others'. Keohane outlines four situations: indifference to others' welfare; instrumental interdependence; situational interdependence; and empathetic interdependence. The first three situations Keohane classifies as egoist, and the last as empathetic. He suggests that there are two patterns of behavior in international relations that are difficult to account for using only egoist explanations. The first is treating rules of international regimes as moral obligations; Keohane argues that by doing so, governments reduce their uncertainty about others' behavior, identify with a group of cooperators, and build their reputations. The second pattern is the existence of unbalanced trade relationships. While egoist explanations may re-interpret such relations as balanced, in a broader perspective these relationships can involve trade of intangible for tangible benefits, the building of reputation, credit or insurance, or instances of generalized reciprocity. Keohane suggests that if self-interest conceptions include empathy, then governments should be better able to form international regimes and facilitate cooperation because of greater shared interests. - abstract by LD Reputation/Politics and law - international
• 95. Kinzer, Stephen. 1993. "A Glimpse of Terrorism: Police Scandal Bares a Bonn Cover-Up." International Herald Tribune, 14 August, 1.
  • An example of use of TFT strategy by a terrorist organization in their dealings with the government. - LD Report on a police scandal in Bonn, Germany. In January 1992 the Red Army responded favorably to the Justice Minister's urgings to call off terrorist killings in exchange for better treatment and possible early releases for jailed Red Army members. After twenty years, German detectives had succeeded in placing an informant in the Red Army. He notified them of a June meeting with a Red Army member the police had been seeking for years. At the meeting, police opened fire on the informant and two other Red Army members. The informant disappeared, and one suspect was caught. The other Red Army member engaged in a shoot out with police and killed one officer. He was captured and witnesses reported that he was killed in cold blood while captive. As a result of the incident, the Red Army stated that "If you don't allow us. . . to live, then you must understand that your elites also cannot live. . . . Even if it is not in our interest, war can only be answered by war." - abstract by LD Politics and law - international/Miscellaneous.
• 96. Kitcher, Philip. 1993. "The Evolution of Human Altruism." Journal of Philosophy 90:497-516.
  • May also be of interest to those whose primary interests are in spatial models, replicator dynamics, noise, and ESS. - LD How does altruistic behavior arise in a Darwinian world? There are two parts to this question: first, how are altruistic tendencies sustained once they are prevalent in a population; and second, how do altruistic tendencies spread when they are rare. Two standard answers to these questions from biology have been selfish genes or kin benefits, and TFT-like strategies. However, Kitcher wants to draw a distinction between biological and human altruism. Biological altruism indicates that humans are ultimately selfish, but this does not fit with everyday notions of human altruism. Human altruism has moral significance, so how does it evolve? First, he argues that not playing the game at all may be an option for some organisms. Altruists may choose to play only with other players who signal they are willing to cooperate. Thus, discriminating altruism can be sustained once it is prevalent. Second, he considers the special features of human altruism, specifically psychological mechanisms, and how such mechanisms might evolve. - abstract by LD Payoffs/Payoffs - comparing different PD matrices/Population structure - clustering/Population structure - information requirements/Theory/Deductive/Psychology.
• 97. Klama, John. 1988. Aggression: Conflict in Animals and Humans Reconsidered. Essex, England: Longman Scientific and Technical.
  • "John Klama" is a pseudonym. The book was edited by John Durant, Peter Klopfer, and Susan Oyama from a text coauthored by John Durant, Erika Honore, Lisa Klopfer, Martha Klopfer, Peter Klopfer, Tamara Kohn, Brian Lessley, Nadav Nur, and Susan Oyama. Examines the scientific and social treatments of aggression. Chapters include popular concepts of aggression, the role of biology and culture, and models of aggression. Chapter 8, "The Evolution of Human and Animal Conflict," discusses ESS and the PD as useful game theoretic tools for thinking about questions in evolutionary biology. Axelrod's work suggests that possibilities for non-aggression exist within the PD, and that non-aggressive outcomes are possible in human PD situations. There is a brief discussion of iterated play and TFT strategy as limits to aggression, and the success of TFT in Axelrod's tournaments. The success of Axelrod's work lies in its using game theory to link human social behavior to cooperation. - abstract by LD Politics and law - domestic/Sociology and anthropology/Psychology/Theory.
• 98. Kogut, Bruce. 1989. "The Stability of Joint Ventures: Reciprocity and Competitive Rivalry." Journal of Industrial Economics 38:183-198.
  • Kogut found that joint ventures between partners with other long term relationships (for example, agreements about technology transfer) were more stable. He tested a number of hypotheses about factors likely to affect cooperation between firms, including one set of variables based on Axelrod's work on TFT reciprocity and information about the expected length of the interaction. - LD The focus of the following empirical analysis is the influence of reciprocity and long-term relationships on the stability of joint ventures. These cooperative incentives are offset by industry structural conditions which may promote competitive rivalry among the partners. To separate these effects on joint venture survival, the hypothesized relationships are proxied by variables drawn from industry and questionnaire data and estimated under a hazard model specification. A theoretical implication of the findings is to suggest a shift of attention from the transaction to the economic relationship as the unit of analysis. Economics and business/Empirical.
• 99. Kollock, Peter. 1993. "'An Eye for an Eye Leaves Everyone Blind': Cooperation and Accounting Systems." American Sociological Review 58:768-786.
  • Using computer simulations that permit degrees of cooperation and introduce "noise" into the environment, [the author] explore[s] the benefits of strategies in which actors use different accounting systems to track ongoing exchanges. By relaxing some stringent assumptions of past work, [the author] chart[s] the conditions under which cooperation may emerge when actors can show degrees of cooperation and when actors' moves are misperceived. Results provide evidence that strategies employing a relaxed accounting system have many advantages. Choices/Noise/Population dynamics - ESS/Limited set of allowable rules - enumerated set/Simulation.
• 100. Komorita, S.S., J.A. Hilty and C.D. Parks. 1991. "Reciprocity and Cooperation in Social Dilemmas." Journal of Conflict Resolution 35:494-518.
  • In computer simulation studies of the prisoner's dilemma conducted by Axelrod (1984), the tit-for-tat (TFT) strategy was found to be most effective. Two important properties of the TFT strategy are based on the reciprocity norm: (1) It is "provocable" and immediately retaliates if the other person defects; and (2) it is "forgiving" and immediately reciprocates cooperation if the other returns to cooperation after defection. Delay of reciprocity for the two types of TFT properties were varied: immediate versus one trial delay. In two experiments, a single naive subject (undergraduate male student) was led to believe that he was playing a two-person prisoner's dilemma, but he actually played against a programmed strategy. The results of both experiments yielded significant effects for delay of forgiveness: Mean proportion of cooperative choices was greater when cooperative overtures were reciprocated immediately than when they were delayed. Two other properties of TFT, "niceness" and clarity, were also assessed. The results are interpreted in terms of operant conditioning principles and in terms of Osgood's GRIT strategy. Limited set of allowable rules - enumerated set/Empirical.
• 101. Kondo, Tetsuo. 1990. "Some Notes on Rational Behavior, Normative Behavior, Moral Behavior, and Cooperation." Journal of Conflict Resolution 34:495-530.
  • The question of cooperation is examined in terms of both the theory of rational choice and the theory of social norms. Is it possible for rational individuals to bring about cooperation, or is normative behavior needed to maintain cooperation? Through the development of the learning-Bayesian PD game, the following propositions are obtained. First, cooperation is maintained by farsighted and perfectly rational individuals who have the expectations of reciprocity. Second, however, this cooperation is not stable; disturbance or deviant behavior overthrows cooperation. Third, even under the existence of disturbance, if individuals behave normatively, they can maintain cooperation; normative behavior works as a stabilizer. Finally, if they behave not only normatively but morally (i.e., according to a categorical imperative), they can even transform noncooperation in to cooperation; moral behavior works as a catalyzer of the transformation. Noise/Population dynamics - ESS/Limited set of allowable rules - limited rationality/Norms/Sociology and anthropology/Deductive/Simulation.
• 102. Kosko, Bart. 1991. "Equilibrium in Local Marijuana Games." Journal of Social and Biological Structures 14:51-65.
  • K-strategies: cooperative behavior (see page 53) r-strategies: competitive behavior (see page 53) - LD [Kosko] examine[s] black market marijuana agriculture with the tools of game theory, population biology, and marginal analysis. A local marijuana game (LMG) is a nonlinear dynamical system, the totality of optimizing behavior of Growers, Ripoffs, and Narcs in an environment where agent behavior does not affect the constant marijuana price. Growers grow, Ripoffs steal, and Narcs eradicate and arrest. Growers resemble K-strategists, Ripoffs resemble r-strategists, and Narcs resemble predators. [Kosko] stud[ies] two types of LMG equilibria: n-person game-theoretic equilibria and ecological steady state carrying capacities. The population ratio of Growers to Ripoffs drives the game-theoretic equilibria. [Kosko] show[s] that Narc increase induces Ripoff increase and that optimal Grower planting strategies resemble the optimal nesting strategies of many species. A minimal mathematical model describes the LMG carrying capacity as the maximal sustainable proportion of planted marijuana patchland given any agent mix. The carrying capacity defines a unique fixed-point equilibrium of the LMG dynamical system, and the LMG system quickly converges to it exponentially. A simple testable relationship describes this equilibrium patch proportion Pe: Pe=1 - (r+n)/g. The equilibrium analysis applies with change of coefficients to black market poppy and coca shrub agriculture. [Kosko] discuss[es] extensions to similar games, including the "border game" played by Aliens, Bandits, and Patrols. Interactions/Payoffs/Population dynamics/Deductive/Collateral research.
• 103. Kraines, David and Vivian Kraines. 1989. "Pavlov and the Prisoner's DIlemma." Theory and Decision 26:47-79.
  • [The authors'] Pavlov learns by conditioned response, through rewards and punishments, to cooperate or defect. [They] analyze the behavior of an extended play Prisoner's Dilemma with Pavlov against various opponents and compute the time and cost to train Pavlov to cooperate. Among [the] results is that Pavlov and his clone would learn to cooperate more rapidly than if Pavlov played against the Tit for Tat strategy. This fact has implications for the evolution of cooperation. Payoffs/Payoffs - comparing different PD matrices/Limited set of allowable rules - enumerated set/Deductive.
• 104. Lamb, Gerri S. 1991. "Two Explanations of Nurse Practitioner Interactions and Participatory Decision Making with Physicians." Research in Nursing and Health 14:379-386.
  • The purpose of this study was to test a theoretical model that integrated two explanations of nurse practitioner interaction and participatory decision making with physicians. The two explanations were derived from technology theory and social exchange theory. Nurse practitioners (N=38) responded to a four-scale magnitude estimation instrument measuring each of four concepts in the model: complexity, expected benefit-cost ratio of interaction, interaction, and participatory decision making. Predictions derived from both theories were supported. Nurse practitioner decisions about interaction with physicians were influenced by the dynamics of social exchange with physicians, as well as the technological requirements of primary care. The findings offer nurse practitioners new strategies for managing professional exchanges on behalf of their patients. Miscellaneous/Empirical/Collateral research.
• 105. Landa, Janet T. and Anthony Wallis. 1988. "Socio-economic Organization of Honeybee Colonies: A Transaction-Cost Approach." Journal of Social and Biological Structures 11:353-363.
  • This paper provides a theoretical explanation of why honeybees do not construct satellite nests for the purpose of extending their foraging range. The large body of existing biological and sociobiological literature on the evolution of social behaviour in honeybees has not addressed this problem. Using a transaction-cost approach, [Landa and Wallis] argue that the costs of identification of 'insiders' (workers commuting between the primary and satellite nests) from 'outsiders' (robbers from other colonies) are too high relative to the benefits of maintaining satellite nests. [The] theory throws light on the issue of limits to co-operation in insect societies by emphasizing economic aspects and provides some additional arguments to the currently popular genetic-based kinship-relatedness theories of altruism and cooperation. The theory has implications for understanding the role of laws and institutions in human societies. Population structure - information requirements/Biological applications/Politics and law - domestic.
• 106. Lazarus, John. 1990. "The Logic of Mate Desertion." Animal Behaviour 39:672-684.
  • Since the fitness consequences of mate desertion are markedly affected by whether the partner also deserts, natural selection is expected to favour desertion decisions that take the mate's decision into account. A model for the evolution of mate desertion is described in which individuals make desertion decisions repeatedly during the period of parental care, choosing the option (desert or stay) that gives them the greater fitness, taking into account whether their mate has already deserted. If the partner still remains, the optimal decision is made assuming that the partner responds optimally in turn. Four patterns of time-dependent payoffs define all possible desertion decisions, three of which produce different kinds of stable evolutionary outcome: both parents stay with the young; both desert; and one deserts, one stays. The fourth pattern ('pre-emptive desertion') also results in both parents deserting but paradoxically, in this case, they sacrifice fitness by so doing. Such uncooperative parents are caught in the well-known Prisoner's Dilemma of game theory and provide a link with recent thinking on the evolution of cooperation. Under conditions of mate choice or repeated interaction between potential mates the payoff pattern that normally produces pre-emptive desertion may result instead in a 'both stay' outcome. When desertion decisions are conditional on the partner's decision, in the way assumed here, desertion outcomes cannot be predicted simply by comparing the costs and benefits of desertion for the male and female at any one time. Rather, one needs to know the way in which these payoffs vary for each partner over the whole of the parental car period. Applications of the model are discussed, with particular reference to uniparental care in fish and biparental care in birds. Choices/Endogenous ending - voluntary exit/Population dynamics - ESS/Biological applications/Deductive/Theory.
• 107. Lazarus, John and Neil B. Metcalfe. 1991. "Tit-for-tat Cooperation in Sticklebacks: A Critique of Milinski." Animal Behaviour 39:987-988.
  • A commentary on M. Milinski (1987) "Tit for Tat in Sticklebacks and the Evolution of Cooperation." Nature 325:433-435. See also Milinski's response to the critique: Milinski (1990) "No Alternative to Tit-for-Tat Cooperation in Sticklebacks." Animal Behaviour 39:989-991. - LD Lazarus and Metcalfe argue that Milinski's (1987) experimental results with stickleback fish (Gasterosteus aculeatus) support a more parsimonious explanation than the TFT cooperation hypothesis he offers. They briefly review Milinski's experiment and argue that the behavioral measure used in the work is inadequate to demonstrate TFT. They offer two alternative explanations for Milinski's results, both of which derive from the experimental situation. First, the fish may be attracted by their own reflections. Second, the apparent presence of a companion may embolden the fish to approach a predator. They say that to demonstrate TFT, two conditions must be met. First, demonstrate that the payoff inequalities make the situation a PD. Second, there must be direct evidence of the dynamics of TFT strategy. - abstract by LD Payoffs/Limited set of allowable rules - enumerated set/Biological applications.
• 108. Leng, Russell. 1993. Interstate Crisis Behavior, 1816-1980: Relaism versus Reciprocity. Cambridge: Cambridge University Press.
  • This book evaluates the realist and psychological perspectives on the outcome of interstate crises. The empirical analysis is based on forty crises during 1816-1980. Among the many findings relevant to issues of reciprocity are the following. States tend to respond in kind and degree to coercive influence attempts. "The manner in which states employing Reciprocating strategies in real world crises depart from a strict TFT strategy represents a prudent adjustment in the application of a firm-but-flexible strategy to fit a hostile and uncertain environment" (p. 189). Evidence is found of niceness, firmness, and forgiveness of Reciprocating strategies used by states, but not of clarity. "reciprocating strategies enjoy a remarkably high success rate (56 percent) compared to the use of other types of influence strategies in defensive situations (12 percent)" (p. 203). - abstract by RA Noise/Reputation/Politics and law - international/Empirical.
• 109. Leng, Russell J. 1993. "Reciprocating Influence Strategies in Interstate Crisis Bargaining." Journal of Conflict Resolution 37:3-41.
  • The findings of a quantitative analysis of the effectiveness of reciprocating influence strategies in militarized interstate crises (MICs) suggest that the success of reciprocating strategies in MICs is related to (1) withholding cooperative initiatives until after the reciprocating party has demonstrated its resolve, (2) the use of carrot-and-stick influence attempts and responses combining firmness with flexibility, and (3) overcoming ambiguity through overt communication of intentions. Reciprocating influence strategies are most likely to be employed by democratic states either defending the status quo or following a change in the status quo in their favor through a fait accompli. When reciprocating strategies are employed against different types of influence strategies, the outcomes are consistent with the intersection of the decision rules of the influence strategies employed by the two sides. Limited set of allowable rules - enumerated set/Politics and law - international/Empirical.
• 110. Lima, Steven L. 1989. "Iterated Prisoner's Dilemma: An Approach to Evolutionarily Stable Cooperation." American Naturalist 134:828-834.
  • Considers the question of how to achieve stable cooperation under conditions of mutual dependence between players and a finite length of game. Lima argues that "strategies for stable cooperation such as TFT represent attempts to remove altruism from apparent cooperation; such attempts place cooperation wholly within the self-interest of the players in an effort to achieve stability. Stable cooperation in the iterated prisoner's dilemma requires that the payers are actually not caught in the dilemma. . . . One unexplored way to achieve this end is to consider a situation in which the fitness of one player depends explicitly on the fitness it allows the other player via its own actions" (p. 828). Within a mutual dependence framework PD payoffs represent probabilities of surviving an attack. Lima's analysis of a finite length PD with mutual dependence found that cooperation decreased as the game neared the end, and that the probability of survival if alone led to an overall decrease in the probability of cooperation. Changing the payoffs also affected the probability of cooperation. Lima's approach to evolutionarily stable cooperation differs from previous ones in two ways: first, a fixed number of plays of the game, which showed that non-altruistic cooperation can be stable; and second, the multiplicative nature of the payoffs. He suggests that mutual dependencies are common to iterated games, and that apparent cooperation may not be the result of TFT-like strategies. - abstract by LD Payoffs/Payoffs - comparing different PD matrices/Population dynamics - ESS/Population structure/Limited set of allowable rules - parameterized rules/Biological applications/Theory/Deductive/Simulation.
• 111. Lindgren, Kristian. 1991. "Evolutionary Phenomena in Simple Dynamics." In Artificial Life II: Proceedings of the Workshop on Artificial Life Held February 1990 in Santa Fe, New Mexico, edited by Christopher G. Langton, Charles Taylor , J. Doyne Farmer, and Steen Rasmussen, pp. 295-312. Redwood City, CA: Addison-Wesley Publishing Company.
  • [The author] present[s] a model of a population of individuals playing a variation of the iterated Prisoner's Dilemma in which noise may cause the players to make mistakes. Each individual acts according to a finite memory strategy encoded in its genome. All play against all, and those who perform well get more offspring in the next generation. Mutations enable the system to explore the strategy space, and selection favors the evolution of cooperative and unexploitable strategies. Several kinds of evolutionary phenomena, like periods of stasis, punctuated equilibria, large extinctions, coevolution of mutualism, and evolutionary stable strategies, are encountered in the simulations of this model. Noise/Population dynamics - ESS/Population dynamics - replicator dynamics/Limited set of allowable rules - parameterized rules/Automata theory/Theory/Simulation
• 112. Linster, Bruce G. 1992. "Evolutionary Stability in the Infinitely Repeated Prisoners' Dilemma Played by Two-state Moore Machines." Southern Economic Journal 58:880-903.
  • See also K. Binmore and L. Samuelson (1992) "Evolutionary Stability in Repeated Games Played by Finite Automata." Journal of Economic Theory 57:278-305. Examines what happens in PD simulations played by two-stage finite automata with the introduction of different forms of mutations. Reviews the literature on ESS in the PD, including Axelrod. The literature tends to be one of two types: one in which no strategy or strategy mix is ESS in the PD, and the other in which "one particular strategy is the only reasonable result of an evolutionary process" (p. 885). The problems Linster identifies with Axelrod's simulations are that he may have biased the results in favor of the success of TFT, and that he did not allow new strategies to enter the simulation. Linster found that GRIM (cooperate until the other player defects, and defect thereafter) was very successful because it could exploit poor strategies better than TFT and scored well with cooperative strategies. He also found that TFT could not take advantage of poor play, and that with small penalties for complexity, nice strategies were immune to successful invasion. Linster suggests that complexity may be similar to the costs of monitoring other players. He concludes by discussing how his work supports results from Binmore and Samuelson (1992). - abstract by LD Payoffs - comparing different PD matrices/Population dynamics - ESS/Limited set of allowable rules - finite state machines/Limited set of allowable rules - limited rationality/Automata theory/Simulation.
• 113. Lombardo, Michael P. 1990. "Tree Swallows and TIT FOR TAT: Response to Koenig." Ethology and Sociobiology 11:521-528.
  • Koenig's (Ethol. and Sociobiol. 9:73-84, 1988) review of Lombardo's (Science 227:1363-1365, 1985) experiment testing the TIT FOR TAT model of reciprocity correctly concluded that the experiment did not demonstrate the existence of reciprocal altruism between parent and conspecific nest intruder tree swallows. However, his review contained errors that preclude a fair evaluation of the experiment and interpretation of its results. Here [Lombardo] respond[s] to these criticisms, reexamine[s] tree swallow behavioral ecology, and suggest[s] that the lack of aggression between parents and intruders can best be modeled as by-product mutualism. [Lombardo] reiterate[s] that the balance between parental aggression and nonaggression toward intruders can be maintained by TIT FOR TAT. Population dynamics - ESS/Biological applications/Biological applications - specific species - birds/Payoffs.
• 114. Lorberbaum, Jeffrey. 1994. "No Strategy is Evolutionarily Stable in the Repeated Prisoner's Dilemma." Journal of Theoretical Biology 168:117-130.
  • Following the influential work of Axelrod, the repeated Prisoner's Dilemma game has become the theoretical gold standard for understanding the evolution of co-operative behavior among unrelated individuals. Using the game, several authors have found that a reciprocal strategy known as Tit for Tat (TFT) has done quite well in a wide range of environments. TFT strategists start out co-operating and then do what the other player did on the previous move. Despite the success of TFT and similar strategies in experimental studies of the game, Boyd & Lorberbaum (1987, Nature, Lond. 327, 58) have shown that no pure strategy, including TFT, is evolutionarily stable in the sense that each can be invaded by the joint effect of two invading strategies when long-term interaction occurs in the repeated game and future moves are discounted. Farrell & Ware (1989, Theor. Popul. Biol. 36, 161) have since extended these results to include finite mixes of pure strategies as well. Here, it is proven that no strategy is evolutionarily stable when long-term relationships are maintained in the repeated Prisoner's Dilemma and future moves are discounted. Namely, it is shown each completely probabilistic strategy (i.e. one that both co-operates and defects with positive probability after every sequence of behavior) may be invaded by a single deviant strategy. This completes the proof started by Boyd and Lorberbaum and extended by Farrell and Ware. This paper goes on to prove that no reactive strategy with a memory restricted to the opponent's preceding move is evolutionarily stable when there is no discounting of future moves. This is true despite the success of a more forgiving variant of TFT called GTFT in a recent tournament among reactive strategies conducted by Nowak & Sigmund (1992, Nature 355, 250) where future moves were not discounted. GTFT, for example, may be invaded by a pair of reactive mutants. Since no strategy is evolutionarily stable when future moves are discounted in the repeated game, the restriction of strategy types to those actually maintained by mutation and phenotypic and environmental variability in natural populations may be the key to understanding the evolution of co-operation. However, the result presented here that the somewhat realistic reactive strategies are also not evolutionarily stable at least in the non-discounted game suggests something else may be going on. For one, the proof that no reactive strategy is evolutionarily stable ironically shows the robustness of TFT-like strategies. Also, a significant invasion of strategies like GTFT (among reactive strategies) and TFT which can be only be invaded by the joint effect of two deviant strategies relies on the maintenance of at least one of the mutants by recurrent mutation or other process. This weakens the paper's results somewhat. Further, it may be possible that some completely probabilistic strategies which are close to their pure counterparts may only be invadible [sic] by strategies with less "errors" in them: thus, a population may tend toward a pure strategy. Such findings could help explain the persistence of certain strategy types in the repeated PD when long-term interaction is possible. Population dynamics - ESS/Theory/Deductive.
• 115. Macy, Michael W. 1991. "Learning to Cooperate: Stochastic and Tacit Collusion in Social Exchange." American Journal of Sociology 97:808-843.
  • The Prisoner's Dilemma formalizes the social trap that arises when individually rational choices aggregate with mutually undesirable consequences. The game-theoretic solution centers on the opportunity for tacit collusion in repeated play. However, not all actors grasp the strategic implications of future interaction. Accordingly, this study reformulates the game as a stochastic learning model in which the behavior of interdependent actors is continually shaped by sanctions and cues generated by their interaction. Computer simulations of a two-person game show that adaptive actors are led into a social trap more readily than are fully rational actors, but they are also better at finding their way out. Prosocial norms appear to be a consequence rather than cause of cooperation but useful in promoting forgiveness of random deviance. The model is then elaborated as an N-way Prisoner's Dilemma. Simulations show how the effects of network size, density, mobility, and anonymity derive from a fundamental principle of collective action, that is, the need to reduce the number of choices that must be fortuitously coordinated in order to escape noncooperative equilibrium. The results also suggest how network structure might evolve in tandem with the cooperation it facilitates. Interactions/Choices/Payoffs - comparing different PD matrices/Endogenous ending - voluntary exit/Population size/Population structure - spatial models/Population structure - information requirements/Norms/Sociology and anthropology/Simulation.
• 116. Mansbridge, Jane J. 1990. "On the Relation of Altruism and Self-Interest." In Beyond Self-Interest, edited by Jane J. Mansbridge, pp. 133-143. Chicago: University of Chicago Press.
  • Argues that altruism needs to be institutionally supported so that altruistic behavior does not become too costly. Altruism and self-interest can be consistent, but they may be difficult to disentangle empirically. She considers the case of the PD. Self-interested solutions include side payments, the Leviathan, the voluntary sovereign, iterated play, and negative sanctions for defecting in voluntary play. Other non-self-interested solutions include making others' good your own, and commitment to a principle that requires cooperation; these solutions in effects change the payoffs of the PD. Mansbridge argues that these solutions need to be sustained by institutions because cooperation on these bases can be undermined by defection. Institutions can help to maintain cooperation. Mansbridge speculates that in-groups may be a protected space in which individuals can express empathy, or cooperate with reduced probability of being a sucker. She suggests that future research might build on when self-interest can be used in conjunction with unselfishness, and that interpreting everything as self-interest leads to underestimating the frequency of altruism. - abstract by LD Payoffs/Population structure - clustering/Psychology/Collateral research
• 117. Mansbridge, Jane J. 1990. "The Rise and Fall of Self-Interest in the Explanation of Political Life." In Beyond Self-Interest, edited by Jane J. Mansbridge, pp. 3-22. Chicago: University of Chicago Press.
  • A short history of the use of self-interest to explain politics and political life, normatively and empirically. Mansbridge briefly reviews work dating back to the Sophists through the incarnation of self-interest in more recent pluralist thought and in the Congressional literature in American politics. She notes some of the challenges to the theory, such as the demonstration of cooperation in the PD when discussion is allowed, and work in sociobiology which suggests selection for cooperation and the existence of reciprocal altruism. She concludes by discussing some recent changes in the concept, which include a focus on maximization using different motives and the importance of specifying context. - abstract by LD Politics and law - domestic/Miscellaneous
• 118. Marinoff, Louis. 1995. "The Failure of Success: How Exploiters Are Exploited in the Prisoner's Dilemma." In Modeling Rational and Moral Agents, Vancouver Cognitive Science Series, edited by Peter Danielson. Oxford: Oxford University Press.
  • Empirical results show that cooperatively-weighted maximization of expected utilities is a relatively robust strategey for iterated Prisoner's Dilemmas (Marinoff, 1992). Cooperative maximizers are nice, provocable, but forgiving, and can attain perpetual mutual cooperation with nice strategies. They are also exploitive; their decision-calculus prescribes perpetual defection against irrational (e.g. rude, mixed probabilistic, and nice but unprovocable) strategies. But in intrafamilial encounters, the maximizing family generates unexpected results: the average scores of cooperative members fall well below their most probable scores. The ultimate source of these surprising non-normal distributions lies in the event matrix, that continuous record of joint outcomes from which expected utilities are computed. Detailed analysis of representative event matrices reveals counter-intuitive structural properties that inhibit sibling recognition between highly cooperative maximizers of expected utility. Thus the performance of this otherwise robust strategy is compromised by an ironic predilection for "sibling rivalry", which in turn suggests that solutions to its internecine problems might be sought within a simulated evolutionary paradigm. Limited set of allowable rules/Deductive
• 119. Marinoff, Louis. 1990. "The Inapplicability of Evolutionarily Stable Strategy to the Prisoner's Dilemma." British Journal for the Philosophy of Science 41:461-472.
  • Reviews the formulation of Axelrod and Hamilton's (1981) PD and Maynard Smith's concept of ESS and the Hawk-Dove game. Argues that importing ESS into the PD is problematic on several counts. First, Axelrod and Hamilton assume that the strategy Always Defect is ESS in the PD, but the tournament results indicate the relative superiority of TFT. The question "why do the theoretical and the empirical environments support different optimal strategies" is left unanswered (p. 468). Second, theoretically, if the discount parameter is very large, then Always Defect cannot invade TFT and TFT is ESS. However, this theoretical result does not explain the empirical results of the tournament. Finally, Axelrod and Hamilton suggest that the emergence of the ESS of TFT in the PD is an example of altruism in evolutionary theory. Marinoff argues that this resolution is unsatisfactory because, by definition, ESS cannot be invaded under the influence of kinship. Thus, if Always Defect is ESS, then TFT cannot emerge through kinship or the chance of repeated interaction (forms of natural selection), because this is not possible by definition. Marinoff tests the assumptions that Always Defect and TFT are ESS. He shows mathematically that no strategies are ESS in the PD. - abstract by LD Population dynamics - ESS/Theory/Deductive.
• 120. Marinoff, Louis. 1992. "Maximizing Expected Utilities in the Prisoner's Dilemma." Journal of Conflict Resolution 36:183-216.
  • This article reports the results of a computer experiment with iterated prisoner's dilemmas conducted as an interactive tournament of competing strategies and families of strategies. The purposes of the experiment are to complement Axelrod's previous tournaments and to supplement his findings. For his competitions, Axelrod drew on an unregulated population of strategies. In contrast, the interactive tournament regulates the composition of the strategic population itself. By grouping the competing strategies into families, whose members are related in certain ways, the performance characteristics of particular strategies are studied by varying parameters in their familial program logic. By this means, optimal strategic performance can be "bred" into domesticated populations. Two new methods are developed for assessing strategic robustness: combinatorial analysis and eliminatory ecosystemic competition. The strategy that maximizes expected utility with the most cooperative initial weighting is found to be most robust in the interactive environment. Population dynamics - replicator dynamics/Limited set of allowable rules - enumerated set/Simulation/Tournament.
• 121. Marks, R.E. 1992. "Breeding Hybrid Strategies: Optimal Behaviour for Oligopolists." Journal of Evolutionary Economics 2:17-38.
  • Oligopolistic pricing decisions - in which the choice variable is not dichotomous as in the simple prisoner's dilemma but continuous - have been modeled as a generalized prisoner's dilemma (GPD) by Fader and Hauser, who sought, in the two MIT Computer Strategy Tournaments, to obtain an effective generalization of Rapoport's Tit for Tat for the three-person repeated game. Holland's genetic algorithm and Axelrod's representation of contingent strategies provide a means of generating new strategies in the computer, through machine learning, without outside submissions. The paper discusses how findings from two-person tournaments can be extended to the GPD, in particular how the author's winning strategy in the Second MIT Competitive Strategy Tournament could be bettered. The paper provides insight into how oligopolistic pricing competitors can successfully compete, and underlines the importance of "niche" strategies, successful against a particular environment of competitors. Bootstrapping, or breeding strategies against their peers, provides a means of examining whether "repetition leads to cooperation": [Marks] shows that it can, under certain conditions, for simple and extended two- and three-person GPD repeated games. The paper concludes with a discussion of the relationship between Selten's trembling-hand perfect equilibrium and Maynard Smith's evolutionarily stable strategies, with practical simulations of successful and unsuccessful "invasions" by new strategies. Interactions/Choices/Payoffs - comparing different PD matrices/Population dynamics - ESS/Economics and business/Limited set of allowable rules - finite state machines/Limited set of allowable rules - parameterized rules/Automata theory/Simulation/Tournament.
• 122. Martin, Lisa L. 1992. Coercive Cooperation: Examining Multilateral Economic Sanctions. Princeton: Princeton University Press.
  • Examines the problem of cooperation in the context of two states deciding whether to impose economic sanctions on a third. She develops a game theoretically based model, which she examines using statistical data and case studies. Based on her model, there are three kinds of games: coordination, coercion, and coadjustment. The PD epitomizes coadjustment games. Martin's analysis focuses on the importance of credible commitment of the leading state, and the role of self-imposed costs and institutions as commitment mechanisms. - abstract by LD Payoffs/Reputation/Politics and law - international/Empirical.
• 123. Martinez Coll, Juan Carlos and Jack Hirshleifer. 1991. "The Limits of Reciprocity: Solution Concepts and Reactive Strategies in Evolutionary Equilibrium Models." Rationality and Society 3:35-64.
  • Besides meeting the Nash condition (Axelrod's so-called "collective stability"), an evolutionary equilibrium must be an attractor - either an evolutionary equilibrium point (EEP) or an evolutionary equilibrium region (EER). In this analysis of Prisoners' Dilemma and Chicken environments, the "archetype" strategies (COOPERATE and DEFECT in Prisoners' Dilemma and COWARD and DAREDEVIL in Chicken) were augmented by the "reactive" strategies TIT FOR TAT and BULLY - entering separately in 3x3 and jointly in 4x4 interactions. An instant-response assumption was employed that stacked the deck somewhat in favor of TIT FOR TAT. Nevertheless, in no case was all-TIT FOR TAT ever an EEP, although some conditions generated a mixed EER with only "nice" behaviors represented. A credible model should imply an equilibrium in which both "mean" and "nice" behaviors are represented. Remarkably, none of the conditions postulated here led to such an outcome. This unsatisfying result suggests the importance of introducing a PUNISHER strategy as described elsewhere by the authors. Interactions/Payoffs/Population dynamics - ESS/Limited set of allowable rules - enumerated set/Theory/Simulation.
• 124. Masters, Roger D. 1989. The Nature of Politics. New Haven: Yale University Press.
  • Attempts to provide a naturalist perspective on questions of human nature and the state, drawing on political theory and empirical data from various disciplines, including biology and political science. Masters argues that language makes it possible for political and social institutions to become self-perpetuating systems, and that natural selection can affect the origins and functions of these human-made institutions. He says that the evolutionary or naturalist approach he describes can provide an objective basis for judging the rightness or justice of political institutions. The book is divided into four parts. The first examines the applications of biological research to studies of human nature. Chapter 1 focuses on the question of whether human behavior is fundamentally selfish or altruistic. Masters suggests that the tendency toward cooperation is both innate and learned (or genetic and cultural). The second section of the book explores the origins of the centralized state by linking theories of natural selection to theories of social cooperation. The third and fourth sections examine implications of the evolutionary approach for the social sciences. Chapter 5, "The Nature of the State," suggests that in order to explain how the state came to exist, there must be some explanation for social cooperation. Masters argues that the collective goods problem parallels the problem of the origin of the state. Using the PD in various situations (e.g., kin, non-kin), Masters shows that social cooperation is most likely when there is mutual benefit, reciprocal benefit, or kin facing conditions that punish selfishness or reward cooperation. He then considers the case of the n-person PD, or tragedy of the commons. Masters argues that when collective goods are at stake in large groups, the risk of mutual harm outcomes (all defect outcomes) increases the benefits of having the enforceable norms or rules of states. Chapter 6 considers the question of why the bureaucratic form of the state evolved, and Chapter 7 discusses the roles of exit and ostracism associated with the emergence of the state. The epilogue outlines consequences of the evolutionary approach for social science, standards of moral judgment, and understanding humanity's role in the world. - abstract by LD Interactions/Payoffs - comparing different PD matrices/Endogenous ending - ostracism/Population structure - clustering/Politics and law - domestic/Sociology and anthropology/Theory/Empirical.
• 125. Matsuda, Hiroyuki. 1989. "A Game Analysis of Reciprocal Cooperation: Sequential Food-Sharing and Sex Role Alternation." Journal of Ethology 7:105-112.
  • Argues that food sharing in vampire bats (Desmodus rotundus) and hermaphroditic egg-trading in black hamlet fish (Hypolectrus negricans, Serranidae) are not examples of PD, since the roles in these cases are reciprocal and reciprocated. Discussion of reciprocal cooperation. - LD The evolution of reciprocal cooperation between non-relatives is studied. Food-sharing of vampire bats studied by Wilkinson (1984) and egg-trading of simultaneous hermaphroditic fish studied by Fischer (1980) are respectively considered as Thompson's reciprocal assistance and the iterated Hero game. Those models predicted the following: (1) Reciprocal assistance between adult bats is evolutionarily stable if they repeatedly interact for a long time. However, (2) the cost for an adult to assist a juvenile is too high to be compensated by the benefit from the juvenile. (3) A particular signal, which determines the sex role of each partner, is always displayed by a "heroic" partner which releases eggs with a larger cost. (4) If alternation of sex roles is established, then the evolutionarily stable frequency of displaying a signal of egg-release increases as the frequency of divorce decreases, and (5) a "cheating" strategy, which releases sperm on every spawning bout, is less advantageous than reciprocal cooperation. Biological applications/Deductive/Biological applications - specific species - bats/Biological applications - specific species - fish/Endogenous ending - ostracism/Payoffs/Population dynamics - ESS/Limited set of allowable rules - parameterized rules.
• 126. Matsuda, Hiroyuki and Yasushi Harada. 1990. "Evolutionarily Stable Stalk to Spore Ratio in Cellular Slime Molds and the Law of Equalization in Net Incomes." Journal of Theoretical Biology 147:329-344.
  • The authors propose the law of equalization of net incomes, which suggests that the utility of private property depends on the total amount of common property; the utility of private property increases as the total amount of common property increases. For two individuals with different levels of total resource investment, the law suggests that the individual whose total investment is greater than or equal to a critical amount will invest in both private and common property. The individual whose total resource investment is less than or equal to some critical amount will invest solely in private property. These results indicate that individuals use information on the number of others forming a group and the total amount of resource investment by others when deciding how much of their own resources to invest in common. LD The evolutionarily stable stalk ratio (ESSR) in the cellular slime molds is studied when the fruiting body is formed by multiple clones of various size. The survival probability of a spore cell is assumed to depend on the stalk ratio and the fruiting body size. ESSR is obtained as the non-co-operative equilibrium (Nash solution) that maximizes the fitness of each clone. The following two predictions are obtained: (1) the number of spore cells produced by each clone forming a fruiting body tends to be equalized, even if a variation in clone size exists. As a result, the larger clones do not necessarily enjoy higher fitness than the smaller ones. (2) The stalk ratio and the overall fitness of the fruiting body decrease as the genetic diversity in the fruiting body increases. A condition for the stalk to spore ratio to be invariant of the overall fruiting body size is also investigated. Finally, the "law of equalization in net incomes" is proposed, extending result (1) into the broader range of resource allocation problems. Interactions/Payoffs/Population dynamics - ESS/Population structure/Biological applications/Deductive/Collateral research.
• 127. Mesterton-Gibbons, M. 1991. "An Escape from 'the Prisoner's Dilemma'." Journal of Mathematical Biology 29:251-269.
  • Conventional escapes from the paradox that noncooperation between two organisms may be rational, even when cooperation would yield a higher reward to each, are based on the mechanism of reciprocity; but an analytical model of foraging among oviposition sites reveals a more immediate rationale, namely, the equivalence of selfishness and altruism. The resulting game is unconditionally 'the prisoner's dilemma' if the players have perfect recognition; however, in the absence thereof and for three different parameter regimes, it yields either the prisoner's dilemma, or two evolutionarily stable strategies, or a unique cooperative ESS. Thus unrecognition can favor cooperation; and environments can exist in which cooperation persists, or even invades, without reciprocity. The results suggest that different mechanisms for cooperation may operate at different levels of neural complexity. Payoffs/Population dynamics - ESS/Population structure - information requirements/Biological applications/Deductive.
• 128. Mesterton-Gibbons, Michael. 1993. "The Comedy of the Commons: A Comment on Wildavsky and Friedman." Rationality and Society 5:537-540.
  • Outlines that payoff matrix and inequalities that define a PD. Shows how in a resource-rich environment, players face not a PD, but the cooperator's dilemma, or comedy of the commons, in which cooperation arises spontaneously. In a resource scare environment, players face a PD, or tragedy of the commons. - abstract by LD Payoffs/Biological applications/Sociology and anthropology.
• 129. Mesterton-Gibbons, Michael. 1994. "The Comedy of the Commons Revisited: A Comment on Wildavsky." Rationality and Society 6:519.
  • Response to a comment by Wildavsky on Mesterton-Gibbons's (1993) "The Comedy of the Commons." Mesterton-Gibbons states that he "did not say that differences in culture cannot change the nature of a game; rather, [he] said that changes in the environment can change the nature of a game even if you hold the culture constant" (p. 519). Payoffs/Sociology and anthropology.
• 130. Mesterton-Gibbons, Michael. 1993. "Game-Theoretic Resource Modeling." Natural Resource Modeling 7:93-147.
  • Games - mathematical models of strategic interaction - embrace a multitude of disciplines, in each of which they form a largely separate field of study with its own traditions and priorities. Game-theoretic resource modeling concerns itself primarily with strategic aspects of externalities arising from joint use of the commons, although it also deals with externalities of privately owned resources and with questions of fairness is allocating shared resource costs. This essay surveys resource games - in fisheries, forestry, water resources and environmental regulation - within a novel unifying framework, assesses their contribution to current understanding of resource issues, and indicates their promise for the future. Population dynamics/Population structure/Biological applications/Sociology and anthropology/Deductive/Miscellaneous.
• 131. Mesterton-Gibbons, Michael. 1992. An Introduction to Game-Theoretic Modelling. Redwood City, CA: Addison-Wesley Publishing.
  • Introductory textbook to game theory that includes chapters on solution concepts to cooperative and noncooperative games, ESS, characteristic function games, and the PD and cooperation. The chapter "The Prisoner's Dilemma and the Rationality of Cooperation" discusses reciprocative strategies, and examines the resilience of TFT, given its success in the Axelrod tournaments, under different conditions. - abstract by LD Population dynamics - ESS/Deductive/Miscellaneous.
• 132. Mesterton-Gibbons, Michael and Lee Alan Dugatkin. 1992. "Cooperation among Unrelated Individuals: Evolutionary Factors." Quarterly Review of Biology 67:267-281.
  • There are three categories of cooperation among unrelated individuals: group-selected behavior, reciprocal altruism, and by-product mutualism. A simple two-strategy game, the cooperator's dilemma, which generalizes the well-known prisoner's dilemma, provides a coherent framework for distinguishing the mechanisms that support cooperation in each category. The mechanism for distinguishing group-selected behavior is deme structure; variance among trait groups allows natural selection to favor individuals in groups with a higher frequency of cooperators. A prerequisite for this mechanism to work is differential productivity of trait groups. The mechanism for cooperation in reciprocal altruism is scorekeeping, which allows cooperators to retaliate against noncooperators by conditioning their behavior on that of others. A prerequisite for this mechanism is that the expected number of interactions between individuals be sufficiently high. In nonsessile organisms, individuals must typically have a sufficiently well-developed neural apparatus to recognize opponents and remember their actions on previous encounters. The mechanism for cooperation in by-product mutualism is the common enemy of a sufficiently adverse environment. A prerequisite for this environment is the boomerang factor, that is, any uncertainty that increases the probability that a noncooperator will be the victim of its own cheating. These mechanisms may operate, alone or together, in widely divergent taxa. Empirical studies suggest that cooperation among unrelated cofoundresses in the desert seed harvester ant, Messor pergandei, exemplifies group-selected behavior. Other recent experiments suggest that predator inspection in fish may satisfy the prerequisites for cooperation via reciprocity between nonsessile organisms. Cooperative hunting of large prey in lions appears to be an example of by-product mutualism. Both theoretical and empirical work are needed to distinguish among these possibilities, and future research directions are discussed. Payoffs/Population dynamics - ESS/Biological applications/Theory/Deductive.
• 133. Milinski, Manfred. 1993. "Cooperation Wins and Stays." Nature 364:12-13.
  • See also M. Nowak and K. Sigmund (1993) "A Strategy of Win-Stay, Lose-Shift that Outperforms Tit-for-Tat in the Prisoner's Dilemma Game." Nature 364:56-58. Using evolution as a tool for understanding cooperation among egoists, Axelrod's work indicated that TFT was a superior strategy in the PD. However, one problem with TFT is that occasional mistakes lead to cycles of alternating defections. Milinski briefly reviews the simulation work of Nowak and Sigmund (1992; 1993). In one set of simulations (Nowak and Sigmund 1992), Generous TFT (GTFT) emerged as superior to TFT. GTFT is a somewhat more forgiving strategy than strict TFT. In a second set of simulations, Nowak and Sigmund (1993) allowed for any possible mutant strategy based on four probabilities to cooperate. A new strategy, win-stay, lose-shift, or Pavlov, emerged through mutation. Pavlov is a reflexive strategy; if one receives one of the two higher value payoffs from the PD matrix, stay with the previous choice. If one receives one of the two lower value payoffs from the PD, in the next move shift to the other choice. Simulations revealed that Pavlov loses against Always Defect but can invade TFT, and that Pavlov cannot be invaded by Always Defect. Milinski suggests that previous empirical work on animals which has been interpreted as TFT may also be consistent with GTFT or Pavlov, and that Pavlov should be seen in nature, with only young populations playing Always Defect. - abstract by LD Population dynamics - ESS/Limited set of allowable rules - parameterized rules/Biological applications.
• 134. Milinski, Manfred. 1990. "No Alternative to Tit-for-tat Cooperation in Sticklebacks." Animal Behaviour 39:989-991.
  • A response to J. Lazarus and N.B. Metcalfe (1990) "Tit-for-Tat Cooperation in Sticklebacks: a Critique of Milinski." Animal Behaviour 39:987-988. See also the original article: M. Milinski (1987) "Tit for Tat in Sticklebacks and the Evolution of Cooperation." Nature 325:433-435. Argues that the explanations Lazarus and Metcalfe (1990) provide do not explain the fish's behavior in the original 1987 experiment. Milinski responds to the specific criticisms Lazarus and Metcalfe make, as well as addressing whether sticklebacks are attracted to their own reflections (he says that they are not). He provides a discussion of why the experimental situation was a PD, and says that if Lazarus and Metcalfe are correct, the observation of inspection behavior in fish indicates that the fish are not behaving adaptively. - abstract by LD Payoffs/Biological applications/Biological applications - specific species - fish.
• 135. Miller, John H. Forthcoming. "The Coevolution of Automata in the Repeated Prisoner's Dilemma." Journal of Economic Behavior and Organization.
  • A model of learning and adaptation is used to analyze the coevolution of strategies in the repeated Prisoner's Dilemma game under both perfect and imperfect reporting. Meta-players submit finite automata strategies and update their choices through an explicit evolutionary process modeled by a genetic algorithm. Using this framework, adaptive strategic choice and the emergence of cooperation are studied through "computational experiments." The results of the analyses indicate that information conditions lead to significant differences among the evolving strategies. Furthermore, they suggest that the general methodology may have much wider applicability to the analysis of adaptation in economic and social systems. Limited set of allowable rules - finite state machines/Limited set of allowable rules - limited rationality/Population structure - information requirements/Automata theory/Theory/Deductive.
• 136. Miller, Trudi C. 1993. "The Duality of Human Nature." Politics and the Life Sciences 12:221-241.
  • To update the view of human nature that undergirds eighteenth-century British/American political economy, this article reviews literature from diverse subfields of psychobiology. Findings on the structure, function, and evolution of the human brain confirm the duality between reason and passion that is at the core of the science of Hobbes. Contemporary findings across fields indicate that people become emotionally attached to objects, including verbal abstractions, through experiences with pleasure and pain. In contrast, human reasoning is essentially scientific. The duality between passionate motivation and humanity's unique capacity for reasoning makes political science important. By applying the scientific method to the subject of politics, people can design institutions that channel quasi-rational behavior toward outcomes that are mutually beneficial, rather than mutually destructive. Defining human nature correctly is the key to political science, and Smith's addition of the passion of sympathy to Hobbes's narrow definition of human motivation is essential. Norms/Politics and law - domestic/Politics and law - international/Psychology/Theory/Collateral research.
• 137. Milner, Helen. 1992. "International Theories of Cooperation among Nations: Strengths and Weaknesses." World Politics 44:466-496.
  • Milner says that much of the recent international relations work on cooperation has used systemic level analysis and game theoretic approaches, and "that these methodological choices have contributed to both the greatest strengths and most glaring weaknesses of the literature in explaining cooperation among nations" (p. 467). She identifies two major contributions of this literature. The first is a consensus on a definition of cooperation, which occurs "when actors adjust their behavior to the actual or anticipated preferences of others, through a process of policy coordination" (p. 467). In spite of agreement on this definition, there are still difficulties employing this conceptualization in empirical work. The second contribution of this literature is six sets of hypotheses about the conditions under which cooperation is likely to emerge. The hypotheses can be categorized as follows: absolute gains, relative gains, and reciprocity hypotheses; propositions about the number of players or actors involved; iteration hypotheses; international regimes theories; epistemic community hypotheses; and power asymmetries hypotheses. Milner argues that two of the major weaknesses of the recent international relations literature also stem from its use of systemic and game theoretic approaches. The first problem is the development of the assumption of anarchy. The definition of anarchy, which leads to the use of noncooperative games and assumptions that players are egoists, may be inaccurate in reality; the definition has also been used "to justify a host of contradictory assumptions and outcomes" (p. 488). The second weakness of the literature lies in its neglect of domestic politics. This is problematic in part because domestic political conditions may shape states' preferences; in addition, policymakers and negotiators take domestic politics into account when they bargain, so stories about cooperation among states are incomplete without some consideration of states' internal politics. Milner concludes that future international relations work needs to focus more on the interactions among variables linked to the emergence of cooperation, and that the most significant advances will be made by considering the role and effects of domestic politics on cooperation among states. - abstract by LD Interactions/Payoffs/Relative vs. absolute gains/Politics and law - international.
• 138. Molander, Per. 1992. "The Prevalence of Free Riding." Journal of Conflict Resolution 36:756-771.
  • The prospects for the spontaneous emergence of cooperation in n-person prisoner's dilemmas are studies within an evolutionary framework. Both purely cooperative regimes and states representing a mix of conditionally cooperative with noncooperative strategies turn out to be possible outcomes of the selection process, but only the latter correspond to evolutionarily stable strategies. Two-person games differ qualitatively from games with three or more players in that they are more propitious to cooperative regimes. Spontaneous cooperation in general collective-action games therefore appears less likely than much of the recent literature seems to indicate. Interactions/Population dynamics - ESS/Population dynamics - replicator dynamics/Population size/Theory/Deductive.
• 139. Muhlenbein, Heinz. 1991. "Darwin's Continent Cycle Theory and Its Simulation by the Prisoner's Dilemma." Complex Systems 5:459-478.
  • Theoretical biology has largely ignored Darwin's true evolution model. In his famous book about the origin of species, Darwin detailed the importance of a population structure in evolution. He conjectured that a large continent that exists for long periods in a broken condition will be the most favorable for the production of many new forms of life. [Muhlenbein] call[s] this conjecture Darwin's continent cycle theory. In this paper [the author] investigate[s] some of Darwin's arguments in support of his theory by simulating an artificial ecology with the parallel genetic algorithm. The artificial ecology consists of a population playing the Iterated Prisoner's Dilemma. The major emphasis of this paper is on the methodological questions of the simulation. These are the genetic representation, the mapping of the genotypes to phenotypes, and the spatial population structure. Population dynamics - ESS/Population structure - clustering/Population structure - spatial models/Limited set of allowable rules - enumerated set/Automata theory/Theory/Simulation.
• 140. Nachbar, John. 1992. "Evolution in the Finitely Repeated Prisoner's Dilemma." Journal of Economic Behavior and Organization 19:307-326.
  • This paper examines some aspects of 'evolutionary' dynamic behavior in the finitely repeated prisoner's dilemma. The 'fitness' of cooperation found in the best known simulation of this type, that by Robert Axelrod, stems from strategy set restrictions: The game used for the simulation has a continuum of pure cooperation equilibria and no pure defection equilibrium. Some new simulations are presented here for the finitely repeated game. Although cooperation is ultimately exploited and extinguished, dynamic paths can 'pseudo converge' in ways that allow partial cooperation to flourish for extended periods of time. Population dynamics - ESS/Population dynamics - replicator dynamics/Limited set of allowable rules - enumerated set/Theory/Automata theory/Deductive/Simulation.
• 141. Noe, Ronald. 1992. "Alliance Formation among Male Baboons: Shopping for Profitable Partners." In Coalitions and Alliances in Humans and Other Animals, edited by Alexander H. Harcourt and Frans B.M. de Waal, pp. 285-321. Oxford: Oxford University Press.
  • Examines the question of whether theories of reciprocal altruism can be applied to coalition formation among male baboons. Reciprocal altruism suggests that the PD is a valid paradigm for coalition formation. Noe suggests that the PD does not apply in the case of baboons: baboon payoffs do not match those in the PD; there is a great deal of communication among baboons before coalition formation, whereas there is none in the PD; and it is unlikely that male baboons play TFT. In short, the PD metaphor may not apply to coalition formation when players have a choice among partners and there is compeition for preferred allies. Noe goes on to consider alternative explanations for the general patterns of coalition formation among male baboons, as well as the effects of various factors, such as mating success, on coalitions. He concludes by drawing parallels between baboon coalitions and other types of collaboration. - abstract by LD Interactions/Payoffs/Population structure - information requirements/Biological applications/Biological applications - specific species - baboons/Sociology and anthropology
• 142. Noe, Ronald. 1990. "A Veto Game Played by Baboons: A Challenge to the Use of the Prisoner's Dilemma as a Paradigm for Reciprocity and Cooperation." Animal Behaviour 39:78-90.
  • According to a widely accepted paradigm, cooperation among animals resembles an iterated, two-player Prisoner's Dilemma game. In this symmetrical game the two players have equivalent strategic options. Decisions are based only on information obtained in similar interactions with the same player in the past. The Prisoner's Dilemma model ignores the social organization within which cooperation occurs. This paper advocates a set of alternative models based on N-player coalition games that apply especially to collaboration (that is, cooperation and reciprocity) within social groups. The model takes into account the effect of competition for the favours of suitable partners. In Coalition games negotiations are possible and the strategic options of the players can be unequal. An example of a Coalition game, the Veto game, is illustrated by patterns of coalition formation among adult males in a group of wild baboons Papio c. cynocephalus. Interactions/Payoffs/Biological applications/Theory/Biological applications - specific species - baboons.
• 143. Nowak, Martin. 1990. "Stochastic Strategies in the Prisoner's Dilemma." Theoretical Population Biology 38:93-112.
  • A complete analysis of all strategies where the probability to cooperate depends only on the opponent's previous move is given for the infinitely iterated Prisoner's Dilemma. All Nash solutions are characterized. A necessary condition for evolutionary stability against invasion by selection pressure is found. A mutation selection model is discussed which enables us to quantify the possibility to succeed over less cooperative strategies by means of reciprocity. Population dynamics - ESS/Population dynamics - replicator dynamics/Limited set of allowable rules - parameterized rules/Simulation/Theory.
• 144. Nowak, Martin A. and Robert M. May. 1992. "Evolutionary Games and Spatial Chaos." Nature 359:826-829.
  • Much attention has been given to the Prisoners' Dilemma as a metaphor for the problems surrounding the evolution of cooperation. This work has dealt with the relative merits of various strategies (such as tit-for-tat) when players who recognize each other meet repeatedly, and more recently with ensembles of strategies and with the effects of occasional errors. Here [the authors] neglect all strategic niceties or memories of past encounters, considering only two simple kinds of players: those who always cooperate and those who always defect. [The authors] explore the consequences of placing these players in a two-dimensional spatial array: in each round, every individual 'plays the game' with the immediate neighbours; after this, each site is occupied either by its original owner or by one of the neighbours, depending on who scores the highest total in that round; and so to the next round of the game. This simple, and purely deterministic, spatial version of the Prisoners' Dilemma, with no memories among players and no strategical elaboration, can generate chaotically changing spatial patterns, in which cooperators and defectors both persist indefinitely (in fluctuating proportions about predictable long-term averages). If the starting configurations are sufficiently symmetrical, these ever-changing sequences of spatial patterns - dynamic fractals - can be extraordinarily beautiful, and have interesting mathematical properties. There are potential implications for the dynamics of a wide variety of spatially extended systems in physics and biology. Interactions/Payoffs/Population dynamics/Population structure - spatial models/Limited set of allowable rules - enumerated set/Limited set of allowable rules - finite state machines/Automata theory/Simulation.
• 145. Nowak, Martin and Robert M. May. 1993. "The Spatial Dilemmas of Evolution." International Journal of Bifurcation and Chaos 3:35-78.
  • Evolutionary game theory can be extended to include spatial dimensions. The individual players are placed in a two-dimensional spatial array. In each round every individual "plays the game" with its immediate neighbours. After this, each site is occupied by is original owner or by one of the neighbours, depending on who scored the highest payoff. These rules specify a deterministic cellular automaton. [The authors] find that spatial effects can change the outcome of frequency dependent selection. Strategies may coexist that would not coexist in homogenous populations. Spatial games have interesting mathematical properties. There are static or chaotically changing patterns. For symmetrical starting conditions [the authors] find "dynamical fractals" and "evolutionary kaleidoscopes." There is a new world to be explored. Payoffs/Payoffs - comparing different PD matrices/Population dynamics - replicator dynamics/Population structure - spatial models/Automata theory/Theory/Simulation.
• 146. Nowak, Martin A. and Karl Sigmund. 1994. "The Alternating Prisoner's Dilemma." Journal of Theoretical Biology 168:219-226.
  • Reciprocal altruism can often be modelled by a variant of the iterated Prisoner's Dilemma where players alternate in the roles of donor and recipient, rather than acting simultaneously. [The authors] consider strategies realised by simple transition rules based on the previous encounter, and show that the evolutionary outcome for the alternating Prisoner's Dilemma can be quite different from the simultaneous case. In particular, the winner of a simultaneous Prisoner's Dilemma is frequently a "win-stay, lose-shift" strategy based on the payoff experienced in the last round, whereas in the alternating Prisoner's Dilemma, the trend leads towards a "Generous Tit For Tat" strategy. If one allows only for reactive strategies based on the other player's last move, the overall payoff is the same for the alternating or the simultaneous version, although the sequence of moves can be different. In the alternating game "win-stay, lose-shift" strategies can only be successful if there is a longer memory of past encounters. The alternating and simultaneous Prisoner's Dilemma are two very different situations, and the whole existing literature is based on the simultaneous game. Payoffs - comparing different PD matrices/Population dynamics - ESS/Limited set of allowable rules - parameterized rules/Theory/Deductive/Simulation.
• 147. Nowak, Martin and Karl Sigmund. 1990. "The Evolution of Stochastic Strategies in the Prisoner's Dilemma." Acta Applicandae Mathematicae 20:247-265.
  • The authors explore the dynamics of evolution and selection in repeated games. They are interested in the changes favored by selection, not necessarily ones which lead to the optimal points in games. They begin by modeling a homogeneous population with a few mutants playing the PD. In a repeated PD game with errors, TFT is problematic because players can become trapped in a bad cycle of alternating cooperation and defection. They found that homogeneous populations did not evolve toward TFT, which was not surprising since TFT never does better than its opponents. They suggest that TFT fared so well in the Axelrod tournament because of the particular population of strategies it faced. Their simulations show that when there is noise, it is sometimes best to forget a bad turn, but never a good one. With noise, more generous or forgiving strategies fared better than TFT. The authors also conducted simulations of heterogeneous populations, but given the complicated dynamics, it is difficult to say how general these results are. - abstract by LD Payoffs/Noise/Population dynamics - ESS/Limited set of allowable rules - parameterized rules/Biological applications/Theory/Simulation.
• 148. Nowak, Martin and Karl Sigmund. 1989. "Oscillations in the Evolution of Reciprocity." Journal of Theoretical Biology 137:21-26.
  • Review of work that suggests TFT is not evolutionarily stable and can be invaded. The authors conduct computer simulations to examine applications to evolutionary biology using the continuous game dynamics of Taylor and Jonker (1979). The simulations used stochastic strategies with three parameters and considered cases where there were two, three, or four competing strategies. The simulation outcomes varied based on the variation allowed in the parameters. The results were much less predictable when there was variation in all three parameters; outcomes depended more on the initial conditions and the history. However, the outcome populations often neared TFT values in their time averages, underscoring the robustness of TFT. What is still lacking is a statistical analysis and an intuitive understanding of the process in spite of the prevalence of oscillations. - abstract by LD Limited set of allowable rules - parameterized rules/Noise/Population dynamics - ESS/Population dynamics - replicator dynamics/Simulation/Theory.
• 149. Nowak, Martin and Karl Sigmund. 1993. "A Strategy of Win-Stay, Lose-Shift that Outperforms Tit-for-Tat in the Prisoner's Dilemma Game." Nature 364:56-58.
  • The Prisoner's Dilemma is the leading metaphor for the evolution of cooperative behaviour in populations of selfish agents, especially since the well-known computer tournaments of Axelrod and their application to biological communities. In Axelrod's simulations, the simple strategy tit-for-tat did outstandingly well and subsequently became the major paradigm for reciprocal altruism. Here [the authors] present extended evolutionary simulations of heterogeneous ensembles of probabilistic strategies including mutation and selection, and report the unexpected success of another protagonist: Pavlov. This strategy is as simple as tit-for-tat and embodies the fundamental behavioural mechanism win-stay, lose-shift, which seems to be a widespread rule. Pavlov's success is based on two important advantages over tit-for-tat: it can correct occasional mistakes and exploit unconditional cooperators. This second feature prevents Pavlov populations from being undermined by unconditional cooperators, which in turn invite defectors. Pavlov seems to be more robust than tit-for-tat, suggesting that cooperative behaviour in natural situations may often be based on win-stay, lose-shift. Noise - misimplementation/Population dynamics - ESS/Population dynamics - replicator dynamics/Limited set of allowable rules - parameterized rules/Biological applications/Theory/Simulation.
• 150. Nowak, Martin A. and Karl Sigmund. 1992. "Tit for Tat in Heterogenous Populations." Nature 355:250-253.
  • The authors' results suggest that generosity pays under uncertainty. - LD The 'iterated prisoner's dilemma' is now the orthodox paradigm for the evolution of cooperation among selfish individuals. This viewpoint is strongly supported by Axelrod's computer tournaments, where 'tit for tat' (TFT) finished first. This has stimulated interest in the role of reciprocity in biological societies. Most theoretical investigations, however, assumed homogeneous populations (the setting for evolutionarily stable strategies) and programs immune to errors. Here [the authors] try to come closer to the biological situation by following a program that takes stochasticities into account and investigates representative samples. [The authors] find that a small fraction of TFT players is essential for the emergence of reciprocation in a heterogeneous population, but only paves the way for a more generous strategy. TFT is the pivot, rather than the aim, of an evolution towards cooperation. Noise/Population structure - spatial models/Limited set of allowable rules - parameterized rules/Theory/Simulation.
• 151. Opp, Karl-Dieter. 1988. "Spontaneous Order and Tit for Tat: Some Hypotheses and an Empirical Test." Journal of Institutional and Theoretical Economics 144:374-385.
  • Spontaneous order is a situation in which "within given institutional constraints, actors can try to reach their own private goals. It also means that the result of the individual decisions is a Pareto-optimal condition - a state, in which no one can gain further advantages inflicting disadvantages on somebody else" (p. 374). The question for spontaneous order situations is what kinds of restrictions or regulations need to be placed on individuals in order to reach the Pareto optimum. Opp suggests that market exchanges resemble a PD, so the work on the evolution of cooperation can be applied to understanding markets. If people use strategies such as TFT, then only minimal institutional restrictions would be needed to achieve cooperation in markets. Opp examined whether people employed TFT-like strategies in a real life situation. He found that people did not behave in accordance with strict TFT; there was a higher degree of non-cooperation and exploitation in the responses than TFT would generate. Opp suggests that other factors such as personality may be important to understanding cooperation, and that future research should develop specific, testable models for cooperation to apply in real situations. - abstract by LD Economics and business/Empirical.
• 152. Orbell, John M. and Robyn M. Dawes. 1993. "Social Welfare, Cooperators' Advantage, and the Option of Not Playing the Game." American Sociological Review 58:787-800.
  • [The authors] outline a model of how freedom to choose between playing and not playing particular Prisoner's Dilemma games can (1) increase social welfare and (2) provide relative gains to intending cooperators. When cooperators are relatively more willing to play, they will interact more frequently with each other and their payoff per encounter will be higher - potentially higher than that of intending defectors. Because the cooperate-cooperate outcome produces more wealth than any other, optional entry will increase social welfare. [The authors] report laboratory data showing: (1) Social welfare and the relative welfare of intending cooperators are higher when subjects are free to choose between entering and not entering particular Prisoner's Dilemma relationships; and (2) this difference is a consequence of intending cooperators' greater willingness to enter such relationships, not because of any capacity to recognize and avoid intending defectors. [The authors] speculate about the cognitive processes that underlie this result. Choices/Endogenous ending - voluntary exit/Population structure/Psychology/Theory/Empirical.
• 153. Pahre, Robert. 1994. "Multilateral Cooperation in an Iterated Prisoner's Dilemma." Journal of Conflict Resolution 38:326-352.
  • There is a remarkable consensus among scholars of international relations that bilateral cooperation is easier to achieve than multilateral cooperation. This essay proposes a formal model to show that this is incorrect, because a multilateral agreement may achieve what an equivalent series of bilateral agreements cannot. The author explores formally several different enforcement mechanisms, suggesting that the argument is robust. Throughout the essay, the author uses examples from the Marhsall Plan to illustrate the logic of this result. The argument has implications for other substantive topics, such as most-favored-nation cluses in trade agreements, the theory or hegemonic stability, analysis of the European Economic Community, the politics of linkage, and the study of multilateralist norms. Interactions/Norms/Politics and law - international/Theory/Deductive.
• 154. Parkhe, Arvind. 1993. "Strategic Alliance Structuring: A Game Theoretic and Transaction Cost Examination of Interfirm Cooperation." Academy of Management Journal 36:794-829.
  • Maintaining robust cooperation in interfirm strategic alliances poses special problems. Such relationships have received growing attention in recent research grounded in game theory, which has suggested that some alliance structures are inherently more likely than others to be associated with high opportunity to cheat, high behavioral uncertainty, and poor stability, longevity, and performance. The present study merged these theoretical insights with the logic of transaction cost economics in a general model of alliance structuring and tested it with data from 111 interfirm alliances. Findings generally supported the model and hypotheses, suggesting the need for a greater focus on game theoretic structural dimensions and institutional responses to perceived opportunism in the study of voluntary interfirm cooperation. Payoffs/Reputation/Economics and business/Psychology/Empirical.
• 155. Pazzani, Michael and Dennis Kibler. 1992. "The Utility of Knowledge in Inductive Learning." Machine Learning 9:57-94.
  • In this paper [the authors] demonstrate how different forms of background knowledge can be integrated with an inductive method for generating function-free Horn clause rules. Furthermore, [the authors] evaluate, both theoretically and empirically, the effect that these forms of knowledge have on the cost and accuracy of learning. Lastly, [the authors] demonstrate that a hybrid explanation-based and inductive learning method can advantageously use an approximate domain theory, even when this theory is incorrect and incomplete. Limited set of allowable rules - parameterized rules/Theory/Automata theory/Deductive/Simulation/Collateral research.
• 156. Pierce, N.E., R.L. Kitching, R.C. Buckley, M.F.J. Taylor and K.F. Benbow. 1987. "The Costs and Benefits of Cooperation between the Australian Lycaenid Butterfly, Jalmenus evagoras, and Its Attendant Ants." Behavioral Ecology and Sociobiology 21:237-248.
  • The larvae and pupae of the Australian lycaenid butterfly, Jalmenus evagoras associate mutualistically with ants in the genus Iridomyrmex. Four ant exclusion experiments in three field sites demonstrated that predation and parasitism of J. evagoras are so intense that individuals deprived of their attendant ants are unlikely to survive. Larvae and pupae of J. evagoras aggregate, and the mean number of attendant ants per individual increases with larval age and decreases with group size. Field observations showed that young larvae could gain more attendant ants per individual by joining the average size group of about 4 larvae than by foraging alone. Aggregation behaviour is influenced by ant attendance: young larvae and pupating fifth instars aggregated significantly more on plants with ants than on plants where ants had been excluded. In return for tending and protecting the larvae, ants were rewarded by food secretions that can amount to as much as 409 mg dry biomass from a single host plant containing 62 larvae and pupae of J. evagoras over a 24 h period. Larval development in the laboratory lasted approximately a month, and larvae that were tended by ants developed almost 5 days faster than larvae that were not tended. However, tended individuals, particularly females, pupated at a significantly lower weight than their untended counterparts, and the adults that eclosed from these pupae were also lighter and smaller. On average, pupae that were tended by ants lost 25% more weight than untended pupae, and in contrast with larvae, they took longer to eclose than pupae that were not tended. These experimental results are discussed in terms of costs and benefits of association for both partners, and of aggregation for the lycaenids. Biological applications/Biological applications - specific species - butterflies/Biological applications - specific species - ants.
• 157. Pollock, Gregory B. 1989. "Evolutionary Stability of Reciprocity in a Viscous Lattice." Social Networks 11:175-212.
  • In randomly mixing populations, reciprocity cannot resist invasion by appropriate concurrent multiple mutants (Boyd and Lorberbaum 1987). Here [Pollock] show[s] how reciprocity can resist such invasion when the clustering ("viscous") population structure necessary for the emergence of reciprocity in a world of defection is retained after reciprocity has saturated the population. A mutation heuristic is introduced under which only forgiving reciprocity can resist Boyd/Lorberbaum invasion in viscous populations; this provides a selective basis for forgiveness and extends TIT FOR TAT's collective stability to evolutionary stability under multiple mutation. The results are generalized to n-person games, where Boyd/Lorberbaum invasion is precluded among insular commons, whether or not reciprocators are forgiving. Non-insular commons are, however, invadable, providing a selection rationale for the maintenance of in/out group distinctions under n-person social ecologies. Interactions/Population dynamics - ESS/Population dynamics - replicator dynamics/Population structure - clustering/Population structure - spatial models/Limited set of allowable rules/Theory/Deductive.
• 158. Pollock, Gregory B. 1988. "Population Structure, Spite, and the Iterated Prisoner's Dilemma." American Journal of Physical Anthropology 77:459-469.
  • Evolutionary stability (sensu Maynard Smith: Evolution and the Theory of Games, Cambridge: Cambridge University Press, 1982) of TIT FOR TAT (TFT) under the social ecology of the iterated Prisoner's Dilemma is a function of the number of pure TFT groups (dyads) in the population, relative to the social position of a focal invading defector. Defecting against TFT always raises the defector's relative intragroup fitness; when Axelrod's (Am. Polit. Sci. Rev. 75:306-318, 1981; The Evolution of Cooperation. New York: Basic Books, 1984) Evolutionary stable strategy (ESS) conditions are met, defection also lowers the absolute fitness of the defector. Here the retaliatory (punishing) character of TFT converts defection into spite, permitting pure TFT groups to sufficiently outproduce the defector for the latter's evolutionary suppression. Increasing the relative impact of spiteful defection on a population lowers the range of evolutionary stability for TFT. When individuals participate in multiple dyads, those participating in the greatest number of dyads are most likely to provide a vehicle for the successful invasion of defections. Within social networks, ESS conditions for TFT are thus individual specific. This logic is generalized to the context of an iterated n-person Prisoner's Dilemma, providing a cooperative solution conceptually identical with TFT in the two-person game. Interactions/Population dynamics - ESS/Population size/Population structure - information requirements/Limited set of allowable rules - enumerated set/Theory/Deductive.
• 159. Powell, Robert. 1991. "Absolute and Relative Gains in International Relations Theory." American Political Science Review 85:1303-1320.
  • The problem of absolute and relative gains divides neoliberal institutionalism and structural realism. The former assumes states focus primarily on their absolute gains and emphasizes the prospects for cooperation. The latter supposes states are largely concerned with relative gains and emphasizes the prospects for conflict. Existing work in international relations theory generally traces the differences between these two theories to different assumptions about states' preferences. Using a simple game-theoretic model, this essay offers a reformulation of the problem of absolute and relative gains that links changes in the states' behavior, the feasibility of cooperation, and especially the states' concern for relative versus absolute gains explicitly to changes in the constraints facing the states. Many of the differences between neoliberal institutionalism and structural realism appear as special cases of the model. Choices/Payoffs/Relative vs. absolute gains/Politics and law - international/Deductive.
• 160. Rapoport, Anatol. 1989. "Book Reviews: J.C. Harsanyi and R. Selten's A General Theory of Equilibrium Selection in Games." Behavioral Science 34:154-158.
  • The primary question of Harsanyi and Selten's A General Theory of Equilibrium Selection in Games is how to find the rational outcome among the several equilibria of an n-person game. They say that there are two criteria important to selection: payoff dominance and risk dominance. Harsanyi and Selten also develop solutions that rest on multilevel rationality, which depends on players' beliefs about what other players are thinking. Rapoport notes that Harsanyi and Selten are concerned not only with the internal consistency of their theory, but also with its applications to the social sciences and "real-life social situations." Rapoport suggests that game theory is normative: it says what should happen if people were completely rational. In this, game theory is similar to branches of physics which hypothesize about how events should occur under idealized conditions. However, while it is possible to approach ideal physical conditions, it is unlikely that many completely rational players exist. In addition, the individually-oriented focus of social reality makes noncooperative games a natural model for human interaction. Thus, in situations where the collectively rational outcome differs from the individually rational outcome, such as in the PD, Rapoport suggests that the former may be the morally prescribed outcome (all cooperate), whereas the latter is the rationally prescribed outcome (all defect). Psychological experiments with the PD have revealed that subjects frequently choose to cooperate, even in single-shot situations. Rapoport notes that this may be an opportunity to explore how real human psychology differs from the assumptions of game theory. Rapoport concludes by noting that if one prefers a predictive theory with an analogue to the natural sciences, Harsanyi and Selten's work should be useful. However, if one believes that human relations and interactions are less definitive, then different theories that lead to different kinds of solution concepts may be more satisfying. - abstract by LD Theory/Miscellaneous/Collateral research.
• 161. Rapoport, Anatol. 1994. "Editorial Comments." Journal of Conflict Resolution 38:149-151.
  • Follows V. Akimov and M. Soutchanski (1994) "Automata Simulation of N-Person Social Dilemma Games." Journal of Conflict Resolution 38:138-148. Suggests that learning may be an analogue to natural selection in which neural pathways for rewarded behavior are facilitated, and those for punished behavior are inhibited. Describes the Axelrod tournament and simulation, but notes that nothing was learned in Axelrod's work; that is, the strategies do not mutate. Axelrod's work showed only the differential success of various strategies. Rapoport questions how the simplicity of strategies contributes to their success in the absence of learning, since without learning there is no means through which one strategy can come to recognize another. He suggests that the quality of simplicity may be implicit in the other properties that Axelrod identifies as characteristic of successful strategies. Rapoport compares Axelrod's results with those of Akimov and Soutchanski, who used cellular automata to play the PD and found that the most successful strategy (it survived "most frequently asymptotically") was a TFT analogue. Akimov and Soutchanski suggested that the TFT analogue did well because there were peace initiatives (which responded to defection with cooperation) in the population that helped to break TFT players out of "echo" sequences (alternating defection and cooperation: CD, DC, CD, DC, . . .) or lock-ins on always defect (which can occur in paired TFT strategies when there is noise). Rapoport notes that introducing genuine learning into social dilemma games raises many new opportunities and possibilities for research. - abstract by AR and LD Population dynamics/Theory/Automata theory.
• 162. Rapoport, Anatol. 1991. "Ideological Commitments and Evolutionary Theories." Journal of Social Issues 47:83-99.
  • The controversy over the theory of evolution raging in the 19th century was especially intense over the descent of humankind, since the linkage of our species to nonhuman ancestors challenged the creed of our uniqueness as possessors of a soul and as beings created in God's image. Since established religion in those days generally supported the political right, attacks on the theory of evolution came predominantly from that end of the political spectrum. In our day, sociobiologists seek to explain cultural differences by genetic variation. Ironically, this approach, which weakens the case for the uniqueness of humankind, is associated by the critics of sociobiology with the political right. The controversy illustrates the important role of ideological commitment even in the context of natural science. Sociology and anthropology/Theory/Collateral research/Miscellaneous.
• 163. Raub, Werner and Jeroen Weesie. 1990. "Reputation and Efficiency in Social Interactions: An Example of Network Effects." American Journal of Sociology 96:626-654.
  • See also J. Bendor and D. Mooherjee (1990) "Norms, Third-Party Sanctions, and Cooperation." Journal of Law, Economics, and Organization 6:33-63. Reputations emerge if an actor's future partners are informed on his present behavior. Reputations depend on the "embeddedness" of interactions in structures of networks of social relations. They illustrate the effects of such embeddedness on the outcomes of interactions. This article presents simple game-theoretic models of reputation effects on efficiency (in the Pareto sense) in interactions. In a comparative perspective, the authors start with a baseline model of a social system in which reputation effects (of a specific kind) are excluded: actors so not receive information of their partners' behavior in interactions with third parties. Such a system of "atomized interactions" is compared to a system with interactions that are "perfectly embedded": actors are immediately informed on all interactions of their partners with third parties. Efficiency is more easily attained as a result of individually rational behavior in perfectly embedded systems. In a final step, the comparative perspective is broadened, and the extreme assumptions of either an atomized or a perfectly embedded social system replaced. Intermediate cases arise in the consideration of "imperfect embeddedness," that is, a situation in which actors are informed only after some time lag on the behavior of their partners vis-a-vis third parties. It is shown that the conditions for efficiency become more restrictive as the information time lag lengthens. Population size/Population structure/Reputation/Sociology and anthropology/Theory/Deductive.
• 164. Reagan, Ronald. 1986, May 27. "U. S. Interim Restraint Policy: Responding to Soviet Arms Control Violations." President's Statement on Interim Restraint, White House fact sheet, edited by Colleen Sussman, Washington, DC: United States Department of State, Bureau of Public Affairs, Office of Public Communication, Editorial Division
  • Text of Reagan's remarks on US Interim Restraint Policy. Reagan noted that prior to START talks in 1982 the US honored both SALT I and II treaties as long as the Soviets did in order to "foster an atmosphere of mutual restraint;" the US had made clear that this policy required reciprocity (p. 1). The US honored these treaties, but the USSR did not. The US still attempted unilateral cooperation with deep arms reductions. Reagan argued that US response to Soviet noncompliance must be to implement a full arms modernization program. Failure to do so would undercut arms negotiations and send the wrong signal to the Soviets about US resolve in the face of noncompliance. He announced that the US would violate SALT II within the next several months, giving the USSR some time to return to cooperation, which the US would take into account in its future arms decisions. The fact sheet following the speech summarizes the President's statement, and it provides additional details and background on events and decisions mentioned in the speech. It emphasized again the US need to respond to even minor Soviet defections or noncompliance, and that the US would try to meet its strategic needs but remain open to future cooperation with the Soviet Union. - abstract by LD Politics and law - international
• 165. Renaud, F. and T. de Mee�s. 1991. "A Simple Model of Host-Parasite Evolutionary Relationships. Parasitism: Compromise or Conflict?" Journal of Theoretical Biology 152:319-327.
  • The evolutionary biology of host-parasite relationships are considered here using a simple game-theory model in which hosts play against parasite and vice versa. In this model, the players can choose between two strategies (aggressive or not aggressive) and the utility of the game is envisaged in terms of fitness and selective costs. The game solutions suggest that the two types of confrontation are encountered in symbiotic relationships and thus constitute two Evolutionary Stable Strategies (ESS). These observations lead [the authors] to discuss: (i) the status of different kinds of symbiotic relationships (i.e. parasitoidism; parasitism, commensalism and mutualism) related to selective costs and (ii) the position of coevolution in this game theory context. Payoffs/Population dynamics - ESS/Biological applications/Theory/Deductive.
• 166. Robson, Arthur J. 1990. "Efficiency in Evolutionary Games: Darwin, Nash, and the Secret Handshake." Journal of Theoretical Biology 144:379-396.
  • This paper considers any evolutionary game possessing several evolutionarily stable strategies, or ESSs, with differing payoffs. A mutant is introduced which will "destroy" any ESS which yields a lower payoff than another. This mutant possesses a costless signal and also conditions on the presence of this signal in each opponent. The mutant can then protect itself against a population playing an inefficient ESS by matching this against these non-signalers. At the same time, the mutants can achieve the more efficient ESS against the signaling mutant population itself. This construction is illustrated by means of the simplest possible example, a co-ordination game. The one-shot prisoner's dilemma is used to illustrate how a superior outcome which is not induced by an ESS may be temporarily but not permanently attained. In the case of the repeated prisoner's dilemma, the present argument seems to render the "evolution of cooperation" ultimately inevitable. Choices/Payoffs/Payoffs - comparing different PD matrices/Population dynamics - ESS/Population structure - clustering/Population structure - information requirements/Economics and business/Biological applications/Theory/Deductive.
• 167. Ross, Marc Howard. 1988. "Studying Politics Cross-Culturally: Key Concepts and Issues." Behavior Science Research 22:105-129.
  • Axelrod presents the question of cooperation at a sufficiently general level so that it can be considered in a variety of different contexts, which is the challenge that faces cross-cultural research. This provides an opportunity to examine how cultural motives might shape behavior or influence the dynamics of cooperation. - LD The successful cross-cultural study of politics entails two important steps: (1) the identification of appropriate concepts and the specification of their interrelationships, and (2) consideration of how microlevel processes within communities are related to macroprocesses between them. It is argued here that the concepts of authority, conflict, and community provide the theoretical foundation for the cross-cultural study of politics. Each concept can be viewed as a distinct dimension of political life; while taken together, the three can help us understand a wide range of significant political behaviors. These concepts are also crucial in helping to link the more process-oriented view of politics that has dominated political anthropology and political science in recent years with the more structural and static concerns that have been dominant in macrocomparative research, such as cross-cultural studies. Finally, it is argued here not only that explicit attention to political processes within communities offers a dynamic set of research questions for the cross-cultural study of politics but also that more sophisticated cross-community studies can point to important theoretical relationships in the comparative study of politics within communities. Politics and law - domestic/Politics and law - international/Sociology and anthropology.
• 168. Rusciano, Frank Louis. 1990. "The Prisoner's Dilemma as an Extended Arrow Problem." Western Political Quarterly 43:495-510.
  • Argues that the PD is a specific example of a general Arrow problem. Shows how the PD meets the five Arrow conditions (social welfare function, production of unique outcomes from individual orderings, non-dictatorship, Pareto optimality, and irrelevant alternatives), and how the n-person collective action problem is an extended version of an Arrow problem. Rusciano considers various solutions to the PD and collective action problems and shows how they violate different assumptions of Arrow problems. Olson's selective incentives change the payoffs and their rankings and violates the assumptions of production of unique outcomes and irrelevant alternatives. Hardin's elimination of different outcomes and Rapoport's TFT violate these same two Arrow conditions. Rusciano suggests that in certain contexts it may be acceptable to negate these two Arrow conditions, provided the results from the negation are reasonable, in that they are empirically useful and their normative consequences can be assessed. The relationship between the PD and the Arrow problem increases the range of reasonable solutions to the collective action problem by linking these two bodies of research together. - abstract by LD Interactions/Payoffs/Politics and law - domestic/Theory/Deductive/Collateral research.
• 169. Sagan, Carl. 1993, November 28. "A New Way to Think about Rules to Live By." Parade 12-14.
  • Describes an effort to approach the question of the development of moral codes scientifically: are there any rules that make individuals and the whole of society more secure? Considers different ethical rules people are taught, such as the golden rule, and asks which of these rules works best, and how should they be tested. Using Axelrod's results from the PD tournaments and simulation, Sagan looks for the "right mix" of cooperation and defection, pairing the different ethical rules with strategies in Axelrod. Sagan notes the importance of forgiveness in successful strategies, and says that Axelrod's characteristics of successful strategies also apply to life: be nice and forgiving, do not be envious, and punish defection in proportion. - abstract by LD Norms/Limited set of allowable rules - enumerated set/Sociology and anthropology.
• 170. Schaffer, Mark E. 1988. "Evolutionarily Stable Strategies for a Finite Population and a Variable Contest Size." Journal of Theoretical Biology 132:469-478.
  • This paper presents a generalization of Maynard Smith's concept of an evolutionarily stable strategy (ESS) to cover the cases of a finite population and a variable contest size. Both equilibrium and stability conditions are analysed. The standard Maynard Smith ESS with an infinite population and a contest size of two (pairwise contests) is shown to be a special case of this generalized ESS. An important implication of the generalized ESS is that in finite populations the behaviour of an ESS player is "spiteful", in the sense that an ESS player acts not only to increase his payoff but also to decrease the payoffs of his competitors. The degree of this "spiteful" behaviour is shown to increase with a decrease in the population size, and so is most likely to be observed in small populations. The paper concludes with an extended example: a symmetric two-pure-strategies two-player game for a finite population. It is shown that a mixed strategy ESS is globally stable against invasion by any one type of mutant strategist. The condition for the start of simultaneous invasion for two types of mutant is also given. Interactions/Payoffs/Population dynamics - ESS/Relative vs. absolute gains/Theory/Deductive/Collateral research.
• 171. Schubert, Glendon. 1989. Evolutionary Politics. Carbondale, IL: Southern Illinois University Press.
  • A collection of Schubert's research papers on biological aspects of political behavior, intended to serve as an introductory text to biopolitics. The book is broken down into an introduction to biological approaches to political science, followed by five sections: political ethology, political evolution, evolutionary theory, evolutionary development, and political thinking. Axelrod is cited briefly in Chapter 7, "Primates," and in Chapter 17, "Humans." - abstract by LD Politics and law - domestic/Sociology and anthropology/Theory/Collateral research.
• 172. Schuessler, Rudolf. 1989. "The Gradual Decline of Cooperation: Endgame Effects in Evolutionary Game Theory." Theory and Decision 26:133-155.
  • The article provides an evolutionary analysis of a finitely iterated Prisoner's Dilemma. The backward induction reasoning for a breakdown of cooperation in this game is transformed to an evolutionary degradation effect. After the introduction of random variations in the strategies' population size, however, cyclical variations of cooperativeness may appear. A breakdown of cooperation is no longer inevitable. An analysis for all possible payoff relations in Prisoner's Dilemma matrices shows that only four qualitatively different dynamical flows can emerge. Payoffs - comparing different PD matrices/Population dynamics - ESS/Population dynamics - replicator dynamics/Population size/Deductive/Simulation.
• 173. Schuessler, Rudolf. 1990. "Threshold Effects and the Decline of Cooperation." Journal of Conflict Resolution 34:476-494.
  • Game-theoretical analyses of the n-person Prisoner's Dilemma (PD) and of group production have largely ignored the impact of threshold effects on the evolution of cooperation. This article introduces a model where uncooperative action cannot be detected as long as it does not exceed a certain level. The resulting breakdown of cooperation parallels the backward induction effect of a finitely repeated PD and might illustrate pessimistic social theories like Olson's "institutional sclerosis." But surprisingly, cooperation remains at an intermediate level if simple random variations of population size occur. This hints at the possibility that the mentioned pessimism is an often overrated position. Interactions/Population dynamics - ESS/Population size/Politics and law - domestic/Sociology and anthropology/Theory/Deductive/Simulation.
• 174. Sella, Gabriella. 1985. "Reciprocal Egg Trading and Brood Care in a Hermaphroditic Polychaete Worm." Animal Behaviour 33:938-944.
  • Sella suggests that the lengthy courtship period might serve to guard against cheating by providing both partners with information about whether the other partner has eggs and can reciprocate in the female role (p. 943). - LD Ophryotrocha diadema is a simultaneous hermaphrodite polychaete worm with a brief protandrous phase. Its mating behaviour was investigated in order to elucidate the relationships between mating system and reproductive biology. A genetically determined yellow or white coloration of the eggs and body walls made it possible to distinguish the egg releaser from the egg fertilizer. The following main features of the mating system were established. (1) Pairs are formed preferentially between simultaneous hermaphrodites, one partner releasing eggs and the other fertilizing them. There is no selfing. (2) The partners attain spawning synchronization by means of close mutual contact during a fairly time-consuming courtship. (3) Partners regularly alternate sex roles, usually with the same partner more than once in succession. (4) Both partners care for their eggs and protect cocoons of neglected eggs spawned by other pairs. Population structure - information requirements/Biological applications/Biological applications - specific species - worms/Collateral research.
• 175. Sella, Gabriella. 1988. "Reciprocation, Reproductive Success, and Safeguards Against Cheating in a Hermaphroditic Polychaete Worm, Ophrytrocha diadema 'kesson, 1976." Biological Bulletin 175:212-217.
  • Ophryotrocha diadema, a simultaneous hermaphroditic polychaete worm, forms pairs in which both partners regularly alternate sex roles and trade eggs. Since O. diadema has a protandrous phase, safeguards against cheating by a non-reciprocating partner, either male or hermaphrodite, have evolved. Results of a mate choice experiment indicate that protandrous males are generally discarded as mates because they are unable to reciprocate with eggs. Reproductive success (measured by estimating the mean number of egg masses per individual per day) of hermaphrodites paired with males was significantly lower than the reproductive success of hermaphrodites paired with hermaphrodites. This indicates that O. diadema is able to time spawning activity according to the sexual condition of its partner. On the other hand, oogenesis and the production of multiple batches of mature oocytes is independent of the presence of a partner. Worms did not discard mates with substantially fewer eggs. The small size of clutches and the short interval between successive spawnings could be considered a form of egg parcelling, which would prevent exploitation of hermaphroditic individuals by partners unable to reciprocate. Population dynamics - ESS/Biological applications/Biological applications - specific species - worms.
• 176. Sella, Gabriella. 1990. "Sex Allocation in the Simultaneously Hermaphroditic Polychaete Worm Ophryotrocha diadema."Ecology 71:27-32.
  • O. diadema is a simultaneously hermaphroditic polychaete worm with a brief protandrous phase. Pairs are formed preferentially between two simultaneous hermaphrodites, which reciprocally change sex roles and trade eggs. Allocation of reproductive effort during simultaneous hermaphroditic and protandrous phases was evaluated quantitatively, by microscopic examination of both fixed and living specimens. Ovarian tissue is four times as abundant as testicular tissue. The mean number of sperm counted in sectioned animals was taken as an approximation of the number of sperm offered per egg. As expected in species where the mating group always consists of two individuals, this number is low (50 sperm are offered per egg). Like eggs, sperm released at fertilization are replaced within 3 d. Such reduced allocation to testicular tissue allows saving in the physiological cost of sperm production. Efficiency of fertilization in the protandrous phase is low but positively correlated with body length (measured by the number of setigers). A fertilization ratio of 95% is obtained only at the simultaneous hermaphroditic stage. The explains why protandrous males are generally not selected as mates in the reproductive strategy of O. diadema. Self-fertilization is avoided by behavioral constraints. The observed female bias in reproductive effort in the mating system of O. diadema suggests that hermaphroditism should be evolutionarily stable, as the male investment in reproductive effect follows the law of diminishing returns. Biological applications/Biological applications - specific species - worms/Collateral research.
• 177. Shaw, R. Paul and Yuwa Wong. 1989. Genetic Seeds of Warfare: Evolution, Nationalism, and Patriotism. Boston: Unwin Hyman.
  • Examines the question of why warfare exists: what functions do humanity's propensity toward warfare serve? The authors outline a theory drawing on evolution, sociobiology, psychology, anthropology, and political science. They suggest that the evolution of contemporary social behavior originated one to two million years ago, when hominids lived in small kin groups and engaged in intergroup conflict. Contemporary manifestations of the theory appear in nationalism and patriotism. The book provides evolutionary and psychological background for the theory, and then an application of the theory to an analysis of African coups d'etat, nationalism, and patriotism. The final two chapters extend the theory (chapter 8) and discuss implications for the theory and an agenda for future research (chapter 9). Chapter 8, "On Biases, Blinders, and Dead Ends," considers differences between the authors' approach and results from the PD and game theory. The authors say that the result that kin selection is ESS, but other forms of cooperation and reciprocity are not, is consistent with their theory. They provide a review of Axelrod's work and suggest that results in Chapter 5 of The Evolution of Cooperation support their work. Their theory differs from Axelrod based on clusters of individuals as means to bringing about cooperation: Shaw and Wong argue that Axelrod's theory is naive when applied in the context of intergroup warfare, and that his results, based upon round-robin computer tournaments (as opposed to elimination) and simulations, are not subject to the kinds of biases and of ethnocentrism or cognitive limitations that humans are. - abstract by LD Population dynamics - ESS/Population structure - clustering/Politics and law - domestic/Politics and law - international/Sociology and anthropology/Theory/Empirical.
• 178. Sigmund, Karl. 1993. Games of Life: Explorations in Ecology, Evolution, and Behaviour. Oxford: Oxford University Press.
  • A text on the mathematics of evolutionary biology, designed so that readers outside of the field can follow the discussion. The chapters are largely independent thought experiments, using various kinds of games and puzzles as tools. Chapter 8, "Reciprocity and the Evolution of Cooperation," provides a description of the PD situation, the effects of iteration, and a description of Axelrod's results. Sigmund discusses the costliness of noise to a population playing TFT and the importance of being forgiving in such an environment. He conducts several simulations to support the claim that cooperation can evolve in a completely selfish population. He extends the results to interactions among fish and monkeys, and concludes by considering the importance of recognition in aiding the spread of cooperation and the tragedy of the commons as an n-person PD. Other chapters focus on automata, population ecology and chaos, population genetics, evolution and sex, and evolutionary game theory. - abstract by LD Interactions/Noise/Population dynamics - ESS/Population structure - information requirements/Limited set of allowable rules - parameterized rules/Biological applications/Simulation.
• 179. Sigmund, Karl. 1992. "On Prisoners and Cells." Nature 359:774.
  • See also M.A. Nowak and R.M. May (1992) "Evolutionary Games and Spatial Chaos." Nature 359:826-829. Considers approaches to answering the question of how to get mutual cooperation in the PD. Axelrod and Hamilton (1981) and Axelrod (1984) suggest that repetition of the game is one answer. Sigmund notes that in order to retaliate in the PD, one must be able to recognize the other player; thus, "defectors thrive in anonymous crowds, whereas mutual cooperation may be frequent between neighbors" (p. 774). Nowak and May (1992) provide another way out of the single shot PD: territoriality favors cooperation. If players interact with their neighbors, then clusters of cooperators do well and individual defectors fare reasonably well, but defectors surrounded by other defectors have relatively low returns. The shadow of the future is replaced by population viscosity. Sigmund notes that the probability that the players are kin may be high, but there is no need to make this assumption for the territoriality results to hold. He also briefly sketches some of the implications of the Nowak and May approach for cellular automata in the PD, as well as for Hawk-Dove and Stone-Scissors-Paper. - abstract by LD Interactions/Payoffs/Population dynamics - replicator dynamics/Population structure - clustering/Population structure - spatial models/Limited set of allowable rules - finite state machines/Automata theory.
• 180. Simon, Herbert A. 1990. "A Mechanism for Social Selection and Successful Altruism." Science 250:1665-1668.
  • Within the framework of neo-Darwinism, with its focus on fitness, it has been hard to account for altruism, behavior that reduces the fitness of the altruist but increases average fitness in society. Many population biologists argue that, except for altruism to close relatives, human behavior that appears to be altruistic amounts to reciprocal altruism, behavior undertaken with an expectation of reciprocation, hence incurring no net cost to fitness. Herein is proposed a simple and robust mechanism, based on human docility and bounded rationality, that can account for the evolutionary success of genuinely altruistic behavior. Because docility - receptivity to social influence - contributes greatly to fitness in the human species, it will be positively selected. As a conseuqence, society can impose a "tax" on the gross benefits gained by individuals from docility by inducing docile individuals to engage in altruistic behaviors. Limits on rationality in the face of environmental complexity prevent the individual from avoiding this "tax." An upper bound is imposed on altruism by the condition that there must remain a net fitness advantage for docile behavior after the cost to the individual of altruism has been deducted. Population dynamics - replicator dynamics/Population structure/Limited set of allowable rules - limited rationality/Norms/Politics and law - domestic/Sociology and anthropology/Psychology/Theory/Deductive.
• 181. Smillie, David. 1993. "Darwin's Tangled Bank: The Role of Social Environments." In Perspectives in Ethology, Volume 10: Behavior and Evolution, edited by P.P.G. Bateson, pp. 119-141. New York: Plenum Press.
  • Standard evolutionary approaches to understanding social evolution have usually begun with an attempt to specify a basic mechanism that might account for the emergence of complex social systems. In this paper [the author] begin[s] with a characterization of environments constructed by organisms, and particularly those environments consisting of like-members to the target organism. [Smillie] call[s] these "social environments." [He] consider[s], as well, the role of cellular social environments on the developmental processes of multicellular organisms. Cellular environments participate in the determination of cell fate. The evolution of organismic social systems proceeds according to a dynamic where activities within a social context produce selective effects reflected in subsequent generations. These effects have usually been described in terms of competition between individuals. In examining Axelrod and Hamilton's (1981) computer model of cooperation [the author] locate[s] two kinds of competition: competition over scarce resources, which [he] call[s] "zero-sum competition," and competition between tactics, some of which are cooperative in outcome. [Smillie] call[s] this synergistic competition. Cooperative tactics win out in competition with others by making positive contributions to the social environments in which they reside. Through such a process, translated into a more realistic context of evolutionary change, social complexity at different hierarchical levels can be seen as a natural outcome. Analyzing the selective effects of social environments representas a contribution to synthetic theory by describing two types of competition, one of which - synergistic competition - has been largely ignored. Population structure/Theory
• 182. Snidal, Duncan. 1991. "Relative Gains and the Pattern of International Cooperation." American Political Science Review 85:701-726.
  • Snidal demonstrates how different types of games used to model interactions between actors represent different points on a continuum between absolute and relative gains. - LD Many political situations involve competitions where winning is more important than doing well. In international politics, this relative gains problem is widely argued as a major impediment to cooperation under anarchy. After discussing why states might seek relative gains, [Snidal] demonstrate[s] that the hypothesis holds very different implications from those usually presumed. Relative gains do impede cooperation in the two-actor case and provide an important justification for treating international anarchy as a prisoner's dilemma problem; but if the initial absolute gains situation is not a prisoner's dilemma, relative gains seeking is much less consequential. Its significance is even more attenuated with more than two competitors. Relative gains cannot prop up the realist critique of international cooperation theory, but may affect the pattern of cooperation when a small number of states are the most central international actors. Interactions/Payoffs/Relative vs. absolute gains/Politics and law - international/Theory/Deductive.
• 183. Sober, Elliott. 1992. "The Evolution of Altruism: Correlation, Cost, and Benefit." Biology and Philosophy 7:177-187.
  • In the PD, there are three mechanisms that allow for the evolution of cooperation: group selection, kin selection, and reciprocity. Sober demonstrates that the fundamental criterion for the evolution of altruism with any mechanism "depends on the costs and benefits of the behaviors considered and on the degree of correlation that obtains among interacting individuals" (p. 185). He considers first the case where each player interacts with every other player and concludes that in this situation the prospects for altruism are poor. He then examines three forms of pairwise interaction. With random pairings, altruism cannot evolve. When like with like player is paired (such as kin with kin), then altruism evolves when the benefits to the recipient are greater than the costs to the donor. In between these two extreme cases, the degree of correlation between the interactors affects the prospects for the evolution of altruism. Sober's analysis delineates the importance of population structure and interactions to the evolution of altruism. - abstract by LD Population dynamics - ESS/Population structure/Population structure - clustering/Biological applications/Theory/Deductive.
• 184. Sober, Elliott. 1993. Philosophy of Biology. Boulder, CO: Westview Press.
  • Focuses on philosophical problems raised by evolutionary theory. Chapters include what is evolution, creationism, fitness, the units of selection problem, adaptationism, and sociobiology. Sober makes use of Axelrod's work in Chapter 4, The Units of Selection Problem. - LD Chapter 4 outlines the conceptual issues involved in the units of selection problem. Sober argues that Simpson's paradox is an essential element in the fitness relationships involved in the evolution of altruism in PD situations. Sober argues that many arguments against group selection are fallacious. Theory/Sociology and anthropology.
• 185. Sober, Elliott. 1992. "Stable Cooperation in Iterated Prisoners' Dilemmas." Economics and Philosophy 8:127-139.
  • Attempts to render Axelrod's (1984) arguments about the conceptualization of time in the PD more precisely and to evaluate the claim that the stability of cooperation depends on whether the length of the game is fixed or left to chance. Sober first considers games of fixed, finite length. If players in such games are rational, they will play Always Defect, but this says nothing about what to do if one player chooses to use a cooperative strategy like TFT. Sober shows that Always Defect replaces TFT in a finite game through a series of steps (as in the Chainstore Paradox); Always Defect does not replace TFT in one step. In games governed by a probabilistic ending, TFT can be invaded by ALL C, which is in turn invaded by Always Defect. Thus, TFT is not collectively stable in finite games governed by a discount parameter. He suggests that the persistence of TFT may result in part because some possible strategies are not in play at a particular time. Sober argues that absolute stability may be impossible for a strategy, and that more attention should be paid to relative stability of a strategy, or that the definition of a strategy should be restricted so that TFT can be collectively stable. - abstract by LD Population dynamics - ESS/Limited set of allowable rules - enumerated set/Theory/Deductive.
• 186. Sober, Elliott. Forthcoming. "Three Differences between Deliberation and Evolution." In Modeling Rational and Moral Agents, Vancouver Studies in Cognitive Science, edited by Peter Danielson. Oxford: Oxford University Press.
  • Argues that biologists often reason about evolution by using what Sober terms "the heuristic of personification." This is the idea that the traits that will evolve under individual selection are precisely the ones that rational agents would choose if they wanted to maximize fitness. Sober considers shortcomings of this heuristic in PD situations. Population dynamics/Limited set of allowable rules - enumerated set/Limited set of allowable rules - limited rationality/Theory
• 187. Somit, Albert and Steven A. Peterson. 1990. Biopolitics and Mainstream Political Science: A Master Bibliography. De Kalb, IL: Program for Biosocial Research/SSRI, Northern Illinois University.
  • Not an annotated bibliography. - LD Bibliography of work by political scientists from 1963 through 1988 using biological concepts and techniques to study politics and political behavior. There is brief discussion of the contributions of biopolitics to mainstream political science, including the fields of political behavior, public policy, international relations, comparative politics, political philosophy, and research methods. The bibliography is followed by an index of the work by biopolitics subfield. Recent updates of the bibliography are published in the journal Politics and the Life Sciences. - abstract by LD Politics and law - domestic/Politics and law - international/Collateral research.
• 188. Spiro, David E. 1988. "The State of Cooperation in Theories of State Cooperation: The Evolution of a Category Mistake." Journal of International Affairs 42:205-225.
  • Considering cooperation among states, Spiro argues that the "theory of the evolution of cooperation neither helps to explain cooperation, nor meets its own normative goals of reconciling individual liberty with social optima. . . . game theoretic interpretations rely upon added assumptions. . . to such an extent that the model would be better off discarding game theory entirely" (p. 206). He says that to show the evolution of cooperation Axelrod must make unreasonable assumptions that are not logically consistent with the theory of cooperation. Some of his specific criticisms include the following: Axelrod presumes players have enough rationality to play TFT and recognize that others are using it, but they are not rational enough to calculate back from the last move of the game and therefore always defect; and he changes the payoff matrix in the tournament so that early cooperation yielded higher payoffs. Spiro conducted his own tournament (from the information in The Evolution of Cooperation) to examine the robustness of TFT. He says that TFT survives based on crucial assumptions about the payoffs, the play of the game, and the size of the game. Spiro also lodges several criticisms against the empirical evidence Axelrod used, including the two tournaments and the World War I case study. He concludes by suggesting that other avenues to cooperation aside from the PD deserve more attention. - abstract by LD Limited set of allowable rules - enumerated set/Deductive/Politics and law - international/Payoffs/Simulation/Tournament.
• 189. Stanley, E. Ann, Dan Ashlock and Leigh Tesfatsion. 1994. "Iterated Prisoner's Dilemma with Choice and Refusal of Partners." In Artificial Life III, edited by Christopher G. Langton, pp. 131-175. Redwood City, CA: Addison-Wesley.
  • This paper studies the effects of partner selection on cooperation in an artificial ecology. Agents, represented by finite automata, interact with each other through an iterated prisoner's dilemma (IPD) game with the added feature that players choose and refuse potential game partners on the basis of continually updated expected payoffs. Analytical studies reveal that the subtle interplay between choice and refusal in N-player IPD games can result in various long-run player interaction patterns: e.g., mutual cooperation; mixed mutual cooperation and mutual defection; parasitism; and/or wallflower seclusion. Simulation studies indicate that choice and refusal can accelerate the emergence of cooperation in evolutionary IPD games. More generally, however, choice and refusal can result in the emergence and persistence of multiple payoff bands, reflecting the possible existence of ecological attractors characterized by play behavior that is not entirely cooperative. The existence of a spectrum of payoff bands, in turn, leads to the emergence of new ecological behaviors such as band spiking and band tunneling. Choices/Population size/Population structure - information requirements/Limited set of allowable rules - enumerated set/Automata theory/Simulation
• 190. Stein, Janice Gross. 1991. "Deterrence and Reassurance." In Behavior, Society, and Nuclear War, vol. 2, edited by Philip E. Tetlock, Jo L. Husbands, Robert Jervis, Paul C. Stern, and Charles Tilly, pp. 8-72. Oxford: Oxford University Press.
  • Examines some of the strengths and weaknesses of deterrence as a strategy, and attempts to define limits to the utility of this theory. Considers strategies of reassurance that might substitute for or supplement deterrence. Reassurance theories are broadly defined as "a set of strategies that adversaries can use to reduce the likelihood of a threat or use of force" (p. 9). Stein briefly reviews several variants and criticisms of deterrence theory, and examines some of the available empirical evidence used to assess different versions of the theory. Some of the problems Stein identifies with deterrence theory include its failure to consider the relative costs of inaction, the cognitive and motivational biases of decision makers, and the role of domestic political factors. Stein examines five different kinds of reassurance strategies that may replace or aid deterrence strategies in conflict management and avoidance of war. The five strategies are restraint, irrevocable commitments, limited security regimes, development of norms of competition, and the reduction of tension or reciprocity. Stein notes that norms of competition may evolve to aid in cooperation; norms may transform the payoff matrices players use. The reduction of tension suggests how the use of reciprocal strategies such as TFT and GRIT may elicit cooperation. Stein considers some of the disadvantages of using TFT in real situations (such as its poorer performance in situations of relative gain), and underscores the importance of understanding the perceptions and expectations of the players. - abstract by LD Norms/Relative vs. absolute gains/Politics and law - international
• 191. Swistak, Piotr. 1989. "How to Resist Invasion in the Repeated Prisoner's Dilemma Game." Behavioral Science 34:151-153.
  • The evolution of cooperative behavior under conflict situations (Prisoner's Dilemma Game) is an unresolved problem of crucial importance for biological and social sciences. Axelrod's (1980a, 1980b, 1981a, 1981b, 1984) influential (e.g., Maynard Smith, 1982; Peck & Feldman, 1985; Boyd and Lorberbaum, 1987; Milinski, 1987) results showing that cooperation is likely to evolve in groups which play repeated Prisoner's Dilemma game are based in their deductive part on the concept of collective/evolutionary stability. However, there is no pure strategy which is evolutionarily stable (Boyd and Lorberbaum, 1987; Swistak, 1987). This leaves us with no deductive argument in favor of any particular strategy (e.g., TIT FOR TAT) which, in consequence, seriously flaws the reasoning behind the emergence of cooperation. In this paper [Swistak] prove[s] that a "nice" and "unexploitable" strategy is the best one to adopt in asymmetric contests in which there is only one group of invaders. Populations adopting such strategies can resist invasion by any group of invaders which is smaller or equal in size. Being more likely to survive, these populations will facilitate the emergence of cooperation. Population dynamics - ESS/Theory/Deductive.
• 192. Tetlock, Philip E., Charles B. McGuire and Gregory Mitchell. 1991. "Psychological Perspectives on Nuclear Deterrence." Annual Review of Psychology 42:239-76.
  • Brief review of ways in which psychological theory and research fit with work on nuclear deterrence. They begin by reviewing core propositions of deterrence theory. This is followed by a consideration of the determinants of deterrence success and failure, with a heavy emphasis on the role of individual psychological processes. The authors examine some attempts to subsume deterrence theory into a more general theory of international influence. They review pure threat strategies, positive inducements, and what they label mixed influence strategies (TFT and graduated and reciprocated initiatives in tension-reduction (GRIT)). Relying on Axelrod's work in The Evolution of Cooperation, the authors suggest that TFT is easy to understand, and it was effective in the PD tournament. Studies of international crises have also found TFT to be more effective than other strategies. The authors also indicate several drawbacks to using TFT to explain and understand international relations. First, players using TFT may be caught in a series of mutual defections. Second, some international situations might better be described as a game of Deadlock rather than as a PD. In Deadlock the players unilaterally or mutually prefer to defect, so that TFT will not induce cooperation in these situations. Finally, TFT requires perfect perception and control, conditions rarely met in a real world plagued by misperceptions. The authors briefly review work on GRIT and compare these results to those for TFT. GRIT is nicer than TFT, it also promotes cooperation, and there is some empirical evidence to suggest that GRIT may work in international crises. The review concludes with a brief review of public opinion work on national security issues and an argument about the importance of psychological work to work on understanding deterrence theories. - abstract by LD Payoffs/Politics and law - international/Limited set of allowable rules - enumerated set/Noise - misperception/Psychology.
• 193. Tyson, Thomas. 1990. "Believing that Everyone Else is Less Ethical: Implications for Work Behavior and Ethics Instruction." Journal of Business Ethics 9:715-721.
  • Studies consistently report that individuals believe they are far more ethical than co-workers, superiors, or managers in other firms. The present study confirms this finding when comparing undergraduate students' own ethical standards to their perceptions of the standards held by most managers or supervisors. By maintaining a "holier than thou" ethical perception, new and future managers might rationalize their unethical behavior as being necessary for success in an unethical world. A prisoner's dilemma type problem can be said to exist when choosing an unethical behavior becomes each player's dominant strategy and the interaction of dominant behaviors is Pareto inferior. Dispelling the "holier than thou" perception may encourage students to revise their personal behavior payoffs such that the collective benefits that emanate from ethical conduct are favored and the prisoner's dilemma problem is converted into a coordination problem. Payoffs/Economics and business/Empirical.
• 194. Vanberg, Viktor J. and Roger D. Congleton. 1992. "Rationality, Morality, and Exit." American Political Science Review 86:418-431.
  • The morality and rationality issue is explored from an Axelrod-type perspective; that is, it is discussed in terms of recurrent-prisoner's-dilemma-type games and behavioral strategies or programs for playing them. [The authors] argue that intuitive notions of rationality and morality can be shown to be mutually compatible if two assumptions are made: (1) that morality is specified as a general behavioral predisposition or program whose rationality is to be determined in comparison to alternative behavioral programs and (2) that the recurrent game is specified as a prisoner's dilemma game with an exit option. The results of a simulation experiment are presented, showing that a "moral program" (specified as one that never defects, but exits in response to an opponents [sic] defection) is successful in competition with a variety of alternative programs, including Tit for Tat. Choices/Endogenous ending - voluntary exit/Limited set of allowable rules - enumerated set/Simulation.
• 195. Wade, Robert. 1988. Village Republics: Economic Conditions for Collective Action in South India. Cambridge: Cambridge University Press.
  • Examines several villages in a fairly homogeneous area of Southern India and tries to explain variation in the ability of villages to overcome the collective action problem. Some villages are more organized than has been reported for any other Indian villages; others nearby have no village-wide organization at all. Wade argues that the "central variable [predicting overcoming the collective action problem] is the risk of crop loss and social conflict faced by many or all cultivators as a result of the actions of other people or animals" (p. 183). He suggests (in Chapter 11) that the problem of organization in these villages can be described as an n-person PD. The situation is somewhat complicated by the potential for players to free ride, but in the organized vollages this is offset by significant enforcement mechanisms to prevent and detect people breaking the rules. - abstract by RW and LD Interactions/Economics and business/Politics and law - domestic/Sociology and anthropology/Empirical.
• 196. Warsh, David. 1989. "How Selfish Are People-Really?" Harvard Business Review 67:26-34.
  • The importance of repeated play in the Prisoner's Dilemma and the existence of TFT strategies were known long before the publication of The Evolution of Cooperation. Axelrod's major contribution has been to establish the robustness of TFT: TFT scores better than mean strategies, and TFT can invade and win in an evolutionary game. The persuasiveness of Axelrod's case lies in the real world situations TFT is applied, particularly the case of World War I trench warfare. The Evolution of Cooperation is disappointing to humanists and some scientists because Axelrod built on the foundations of self-interest and rational choices based on the simple calculation of payoffs. The problems with this are, first, some behavior does not fit this logic (e.g., voting, helping behavior), and second, the reliance on economics and cost-benefit analysis to explain everything in politics and in everyday life. - abstract by LD Economics and business.
• 197. Weaver, Jim. 1992. Two Kinds: The Genetic Origin of Conservatives and Liberals. Eugene, OR: Baird Publishing Company.
  • Applies Darwinian theories of evolution to the human brain its emotional components, and temperaments in order to examine "the most obvious and bizarre evolutionary compound in our nature: our division into two kinds of people with two different sets of emotions" (p. 2). Weaver labels these two fundamental types in politics conservatives and liberals, or Hawks and Doves, or ethnocentrics and empathics. The former are "aggressive, patriotic, insensitive to the plight of others; [the latter are] thoughtful, compassionate and imaginative" (p. 4). Various chapters in the book describe the two types in different contexts, relying on anecdotal evidence and public opinion polls. Chapter 14, "Attack and Cooperation," uses Axelrod's work in conjunction with that of Richard Dawkins to explain how people came to be divided into different types. Weaver suggests the possibility of using a computer tournament to simulate the evolution of the different types. - abstract by LD Politics and law - domestic.
• 198. Weber, Steve. 1991. Cooperation and Discord in U.S.-Soviet Arms Control. Princeton, NJ: Princeton University Press.
  • An attempt to extend and apply Axelrod's work to explaining U.S.-Soviet cooperation in the domain of arms control. Weber says that game theoretic approaches to cooperation are incomplete because they fail to account adequately for such factors as the selection and implementation of strategies in the international political world. He argues that "the specifics of strategy make a difference. . . . differences among strategies based on reciprocity can explain an important part of the variance in empirical outcomes that is left unexplained by the formal theory" (p. 5). Thus, Weber wants to explore why states choose the strategies they do, and how different strategies may lead to changes in states' behaviors that may or may not lead to cooperation. Chapter 2 reviews current theories of arms control and cooperation, which includes an extended overview of The Evolution of Cooperation, and tries to link Axelrod's work to the empirical problem of U.S.-Soviet arms control. Chapter 3 outlines Weber's approach to the problem. Weber cannot derive specific testable hypotheses that will differentiate outcomes in arms control cases, so he expands the theory to include other empirical concepts to help to explain the variance in outcomes (interests and incentives, saliences, the general political environment, strategic theory, and bureaucratic politics). He develops an alternative typology based on the criteria of contingent reciprocity with three ideal strategies: contingent restraint, enhanced contingent restraint, and contingent threat of escalation. Axelrod's work is used to help determine the kinds of questions addressed in the case study evidence. Chapters 4 through 6 present the case studies used to examine the theory. Chapter 7 reviews the effects of the added empirical concepts on cooperation, and evaluates the performance of the ideal strategies. Weber finds that enhanced contingent restraint best promotes and sustains cooperation. With contingent restraint there is too much temptation for one player to test the resolve of the other, and contingent threat of escalation is the result of a sharp decline in cooperation. - abstract by LD Payoffs/Politics and law - international.
• 199. Weesie, Jeroen. 1993. "Asymmetry and Timing in the Volunteer's Dilemma." Journal of Conflict Resolution 37:569-590.
  • Considers the class of social dilemmas that can be modeled as the Volunteer's Dilemma (VD). In the VOD, one player needs to decide whether to volunteer to contribute to or to produce the collective good outright; "if no volunteer steps forward, all players have to interact in the prisoner's dilemma and hence suffer from an inefficient outcome" (p. 571). The VOD can be used to model many of the situations used to study helping behavior in psychology, such as the murder of Kitty Genovese or the case where a stranger on a crowded subway train appears to have a heart attack. Weesie considers an extension of the game he calls the Volunteer's Timing Dilemma (VTD). In the VTD, the question is not whether to volunteer, but rather to decide when to volunteer, given that no one else has already done so. The VOD and the VTD differ in two respects. First, in the VOD, players cannot tell if someone else has produced the collective good before they make their decision to volunteer. In the VTD, observation of others provides some information about others' willingness to pay the costs and receive the benefits of volunteering to produce the good. Second, in the VTD, the decision cannot be postponed. Weesie provides formal analyses of the equilibria solutions to the symmetric and asymmetric VOD and VTD. He compares the equilibria outcomes of the two symmetric games with respect to individual behavior, collective behavior, and the production of the collective good. Weesie concludes that the solutions to the symmetric VOD and VTD are inefficient, and that a lottery choosing the volunteer in advance would be more efficient. However, such a lottery would be difficult to coordinate because of pre-play communication and transaction costs. - abstract by LD Interactions/Payoffs/Endogenous ending - voluntary exit/Sociology and anthropology/Psychology/Theory/Deductive/Collateral research.
• 200. Weesie, Jeroen and Reinhard Wippler. 1987. "The Cumulation of Incompetence in Organizations." Journal of Mathematical Sociology 12:347-382.
  • The situation in which employees at the same level decide how to allocate resources in order to obtain promotion resembles an n-person PD. - LD An absorbing Markov chain model with a continuous time parameter is used to describe the effects on organizational efficiency of selection for vacancies by selectors with incomplete information on the candidates. Analytical results indicate that the efficiency decreases to zero, eventually at an exponential rate. Simulation studies for large hierarchical organizations of moderate "steepness" (number of employees per boss) and with moderate accuracy of the selection procedure suggest that the amount of time before a substantial decrease in efficiency occurs is generally large compared to a lifetime. Interactions/Limited set of allowable rules - limited rationality/Economics and business/Sociology and anthropology/Theory/Deductive/Simulation/Collateral research.
• 201. Wilkinson, Gerald S. 1990, February. "Food Sharing in Vampire Bats." Scientific American 262:76-82.
  • Considers whether food sharing in vampire bats (Desmodus rotundus) is an act of kin selection, reciprocity, or both. The bats form relatively stable but fluid social and support systems, so that they have an opportunity to engage in reciprocal food sharing. The author's direct observation of the bats indicates that food sharing is preferential with frequent roost mates and often with kin, supporting both kin and reciprocity theories. A food sharing experiment with the bats indicated that they did not share food randomly, but rather appeared to form a reciprocal buddy system. As evidence for the evolutionary stability of food sharing strategies, the author compares expected death rates for bats without food sharing to actual death rates. The article concludes with a discussion of the importance of further work on individual and kin recognition to the study of reciprocity. - abstract by LD Population structure - clustering/Population structure - information requirements/Population structure - spatial models/Population dynamics - ESS/Biological applications/Biological applications - specific species - bats.
• 202. Wu, Jianzhong and Robert Axelrod. Forthcoming. "How to Cope with Noise in the Iterated Prisoner's Dilemma." Journal of Conflict Resolution.
  • Noise, in the form of random errors in implementing a choice, is a common problem in real world interactions. Recent research has identified three approaches to coping with noise: adding generosity to a reciprocating strategy; adding contrition to a reciprocating strategy; and using an entirely different strategy, Pavlov, based on the idea of switching choice whenever the previous payoff was low. Tournament studies, ecological simulation, and theoretical analysis demonstrate: (1) A generous version of Tit for Tat is a highly effective strategy when the players it meets have not adapted to noise. (2) If the other players have adapted to noise, a contrite version of Tit for Tat is even more effective at quickly restoring mutual cooperation without the risk of exploitation. (3) Pavlov is not robust. Noise - misimplementation/Population dynamics - replicator dynamics/Limited set of allowable rules - enumerated set/Theory/Simulation/Tournament.
• 203. Young, H. Peyton and Dean Foster. 1991. "Cooperation in the Short and in the Long Run." Games and Economic Behavior 3:145-156.
  • Examines the evolution of cooperation in the PD with stochastic effects included in the model. Stochastic variability arises for three reasons: 1) players in the population are randomly matched; 2) the PD game that each pair plays has a random stopping probability; and 3) there is a small mutation rate that keeps each strategy from dying out completely. The authors examine these effects when there are just three strategies: Always Defect, Always Cooperate, and TFT. If there is no stochastic variability, then Always Defect is the only attractor of the dynamical system. (TFT is not an attactor because it is payoff-equivalent to Always Cooperate when there are no other strategies.) If no strategy is allowed to die out due to mutation, then both TFT and Always Defect are attractors. When there is both mutation and variability due to effects 1) and 2), the asymptotic behavior of the system depends crucially on the amount of noise, which is inversely proportional to the population size. This follows from the central limit theorem: the more people there are, the more that random variations in their behavior are smoothed out in the population proportions. Foster and Young show that, for large populations (and hence small noise), most of the time most of the people are playing Always Defect, even though initially most people may have started by playing TFT. The reason is that the system tends to drift from TFT to Always Cooperate, which is in turn invaded by Always Defect. They conclude that "For the evolution of cooperation, the moral is this: unless cooperative strategies are constantly being tested by noncooperative ones, cooperation is viable in the short run, but not necessarily in the long run" (pp. 155-156). Interactions/Noise/Noise - misperception/Population dynamics - ESS/Population size/Limited set of allowable rules - enumerated set/Theory/Simulation.
• 204. Young, S. C. and J. Q. Smith. 1991. "Deriving and Analysing Optimal Strategies in Bayesian Models of Games." Management Science 37:559-571.
  • Wilson (1986) gives a backwards induction algorithm for sequentially obtaining the optimal move in a repeated Bayesian game. In this paper [the authors] show how to identify the form of an optimal solution of such a game by a graphical procedure. By means of the Prisoner's Dilemma game, [the authors] illustrate how Wilson's algorithm can be enhanced using the derived analytic form of the solution to produce an explicit optimal strategy. [The authors] can then determine not only how P1 should play on all subsequent moves of the game, but also use ideas of Bayes rationality to discuss whether a given model of P2's reactions is realistic. Payoffs/Population dynamics - ESS/Limited set of allowable rules - limited rationality/Limited set of allowable rules - parameterized rules/Theory/Deductive/Simulation.
• 205. Zagare, Frank C. 1990. "Rationality and Deterrence." World Politics 42:238-260.
  • Argues that the problem with mutual nuclear deterrence occurs when the situation resembles Chicken. If one assumes that the players in the game are instrumentally rational, deterrence is not stable. Thus, one must either reject deterrence theory as logically incoherent, or solve the paradox in some other way. One possible resolution to the paradox is to use TFT strategies: commit to responding to a defection with defection. The question is whether a rational player can make such a commitment, given that the costs of carrying out the threat exceed the costs of capitulation. By allowing players to make strategy commitments TFT resolutions eliminate the security dilemma, but such commitments are not instrumentally rational in Chicken. Zagare suggests that one resolution is to transform the game matrix. He sketches out how deterrence theory might be altered to explain stability and maintain consistency with the axioms of instrumental rationality. For instance, deterrence would constitute a stable relationship if each player were able to convince the other that the costs of capitulation were greater than the costs of response. This would transform the game to PD, where TFT strategies are optimal, but would leave open the question of where each player's preferences and perceptions of costs come from. - abstract by FCZ and LD Payoffs/Politics and law - international.
• 206. Zagare, Frank C. and D. Marc Kilgour. 1993. "Asymmetric Deterrence." International Studies Quarterly 37:1-27.
  • Deterrence of a challenger by a defender is modeled by explicitly relating uncertainty and the credibility of retaliatory threats to the stability of an asymmetric deterrence relationship. In the two-person game model, each player either prefers to fight rather than back down or prefers the reverse. A player knows its own preference, but is uncertain of its adversary's. The challenger may choose to accept the staus quo or initiate a crisis; in the latter case, the defender may capitulate or defend; if it defends, the challenger must either back down or face a situation of open conflict. The perfect Bayesian equilibria of the game are determined, interpreted, and illustrated with historical examples of the success or failure of deterrence. Payoffs/Limited set of allowable rules - limited rationality/Politics and law - international/Deductive.
• 207. Ziegler, Rolf. 1990. "The Kula: Social Order, Barter, and Ceremonial Exchange." In Social Institutions: Their Emergence, Maintenance and Effects, edited by Michael Hechter, Karl-Dieter Opp , and Reinhard Wippler, pp. 141-168. New York: Aldine de Gruyter.
  • The Kula ring is a ceremonial exchange of gifts among tribal societies living in different island groups near Papua New Guinea which establishes and maintains social order and a network of stable relationships. Among these societies, the Kula provides a resolution to the PD questions raised by Hobbes about the emergence of social order. Relying on the results from Axelrod's The Evolution of Cooperation, Ziegler suggests that the conditions for cooperation are most easily met within the ringlike trading pattern of the Kula. He describes the system of reciprocity and exchange in the Kula Ring. Participation in the Kula provides a signal to players in the game about players' beliefs about the payoffs and version of the game they are playing, and thus their willingness to engage in trusting or cooperative behavior. - abstract by LD Interactions/Payoffs - comparing different PD matrices/Population structure - spatial models/Limited set of allowable rules - enumerated set/Reputation/Politics and law - domestic/Politics and law - international/Sociology and anthropology
• 208. Zuckerman, Diana. 1985, March. "Can Genes Help Helping?" Psychology Today 19:80.
  • Brief review of a study conducted by J. Philippe Rushton and colleagues. Rushton surveyed 573 pairs of identical and fraternal twins, gathering measures for altruism, empathy and nurturance. They found that on all three dimensions, women scored higher than men and older persons scored higher than younger ones. Identical twins tended to be similar on these three dimensions, but fraternal twins tended to be different. The researchers attributed half of the altruism scores to genetic influence, half to individual environmental effects, and less than two percent to the twins' home environments. - abstract by LD Biological applications/Psychology/Collateral research.
• 209. Zupan, Mark A. 1990. "Why Nice Guys Finish Last: A Comment on Robert Axelrod's The Evolution of Cooperation." Public Choice 65:291-293.
  • Reviews Axelrod's claims about when cooperation will occur, and considers the simulation evidence and the superiority of TFT. Zupan argues that in real world PD situations it is not always best to play TFT, since Axelrod's findings depend on assumptions which may be violated in the real world game. For example, cooperation may be undesirable when one player does not care about the future, if more than two choices are available to the players, or if interactions are noisy. In addition, the payoff matrix of the PD may not be exogenous but rather depend on the actions the players take. Axelrod's approach may be less desirable in situations where winners keep score and can change the rules of the game. - abstract by LD Choices/Payoffs/Payoffs - comparing different PD matrices/Noise/Miscellaneous.

AUTHOR INDEX

to citation numbers

• A
  • Abbott, Kenneth W. 1
  • Abreu, Dilip, 2
  • Akimov, Vladimir, 3
  • Andreoni, James, 4
  • Ashlock, Dan, 189
  • Aumann, Robert J. 5
  • Axelrod, Robert, 6, 7, 71, 202
• B
  • Badcock, Christopher, 8
  • Benbow, K.F. 156
  • Bendor, Jonathan, 9, 10, 11, 12
  • Betz, Brian, 13
  • Bicchieri, Cristina, 14
  • Binmore, Kenneth, 15
  • Bolle, Friedel, 16
  • Bornstein, Garry, 85
  • Borstnik, B. 17
  • Bower, B. 18
  • Boyd, Robert, 19, 20, 21, 22, 23, 24, 25, 26
  • Brelis, Matthew, 27
  • Broome, Benjamin J. 45
  • Browne, Malcolm W. 28
  • Buckley, R.C. 156
  • Bull, J.J. 29
  • Bunn, George, 30
  • Busch, Marc L. 31
  • Buss, David M. 32
• C
  • Caporael, Linnda R. 33
  • Carrasco, Enrique R. 34
  • Ceccatto, H.A. 35
  • Chagnon, Napoleon A. 36
  • Condlin, Robert J. 38
  • Congleton, Roger D. 194
  • Cox, Chante, 85
  • Crawford, Vincent P. 40
• D
  • Dacey, Raymond, 41
  • Dawes, Robyn M. 33, 42, 152
  • Dawkins, Richard, 43
  • de Mee�s, T. 165
  • Dion, Douglas, 7
  • Downs, George W. 44
  • Drigotas, Stephen M. 85
  • Druckman, Daniel, 45
  • Dugatkin, Lee Alan, 46, 47, 48, 49, 132
• E
  • Evangelista, Matthew, 50, 51
• F
  • Farrell, Joseph, 53
  • Fogel, David B. 54
  • Foster, Dean, 203
  • Frank, Robert H. 56, 57
  • Freeman, John R. 64
  • Friedland, Nehemia, 58
  • Fudenberg, Drew, 59
• G
  • Getty, Thomas, 60
  • Glance, Natalie S. 61, 81
  • Godfray, H.C.J. 62
  • Goldstein, Joshua S. 63, 64
  • Graetz, Kenneth A. 85
  • Grieco, Joseph M. 65, 66, 67
• H
  • Haller, Hans, 40
  • Hanson, David P. 68
  • Harada, Yasushi, 126
  • Harcourt, Alexander H. 69
  • Harpending, Henry C. 70
  • Harrington, John C. 71
  • Hart, Benjamin L. 72, 73
  • Hart, Lynette A. 72, 73
  • Harvey, Frank, 90
  • Hauser, Marc D. 74
  • Hemelrijk, Charlotte K. 75, 76, 77
  • Hill, Greg, 78
  • Hilty, J.A. 100
  • Hirshleifer, David, 79
  • Hirshleifer, Jack, 80, 123
  • Hofacker, G.L. 17
  • Hofacker, I.L. 17
  • Huberman, Bernardo A. 35, 61, 81
  • Hughes, Kirsty, 82
• I
  • Ickes, Barry W. 83
  • Ikegami, Takashi, 84
  • Insko, Chester A. 85
  • Irons, William, 86
• J
  • Jablonowski, Mark, 87, 88, 89
  • James, Patrick, 90
  • Joshi, N.V. 91
• K
  • Kahn, Lawrence M. 92
  • Kalai, Ehud, 93
  • Kaneko, Kunihiko, 84
  • Kennedy, James, 85
  • Keohane, Robert O. 94
  • Kibler, Dennis, 155
  • Kilgour, D. Marc, 206
  • Kinzer, Stephen, 95
  • Kitcher, Philip, 96
  • Kitching, R.L. 156
  • Klama, John, 97
  • Kogut, Bruce, 98
  • Kollock, Peter, 99
  • Komorita, S.S. 100
  • Kondo, Tetsuo, 101
  • Kosko, Bart, 102
  • Kraines, David, 103
  • Kraines, Vivian, 103
  • Kramer, Roderick M. 10
• L
  • Lamb, Gerri S. 104
  • Landa, Janet T. 105
  • Lazarus, John, 106, 107
  • Leng, Russell J. 108, 109
  • Lima, Steven L. 110
  • Lindgren, Kristian, 111
  • Linster, Bruce G. 112
  • Lombardo, Michael P. 113
  • Lorberbaum, Jeffrey, 114
• M
  • Macy, Michael W. 115
  • Mansbridge, Jane J. 116, 117
  • Marinoff, Louis, 118, 119, 120
  • Marks, R.E. 121
  • Martin, Lisa L. 122
  • Martinez Coll, Juan Carlos, 80, 123
  • Maskin, Eric, 59
  • Masters, Roger D. 124
  • Matsuda, Hiroyuki, 125, 126
  • May, Robert M. 144, 145
  • McGuire, Charles B. 192
  • Mesterton-Gibbons, Michael, 127, 128, 129, 130, 131, 132
  • Metcalfe, Neil B. 107
  • Milgrom, Paul, 2
  • Milinski, Manfred, 133, 134
  • Miller, John H. 4, 135
  • Miller, Trudi C. 136
  • Milner, Helen, 137
  • Mitchell, Gregory, 192
  • Molander, Per, 138
  • Mookherjee, Dilip, 11, 12
  • Muhlenbein, Heinz, 139
  • Murnighan, J. Keith, 92
• N
  • Nachbar, John, 140
  • Noe, Ronald, 141, 142
  • Nowak, Martin A. 143, 144, 145, 146, 147, 148, 149, 150
• O
  • Ockenfels, Peter, 16
  • Opp, Karl-Dieter, 151
  • Orbell, John M. 33, 42, 152
  • Oughton, Christine, 82
• P
  • Pahre, Robert, 153
  • Parkhe, Arvind, 154
  • Parks, C.D. 100
  • Payne, Rodger A. 30
  • Pazzani, Michael, 155
  • Pearce, David, 2
  • Pendegraft, Norman, 41
  • Peterson, Steven A. 187
  • Pierce, N.E. 156
  • Pollock, Gregory B. 157, 158
  • Powell, Robert, 159
  • Pumpernik, D. 17
• R
  • Rapoport, Anatol, 160, 161, 162
  • Rasmusen, Eric, 79
  • Raub, Werner, 163
  • Reagan, Ronald, 164
  • Reinhardt, Eric R. 31
  • Renaud, F. 165
  • Rice, W.R. 29
  • Richerson, Peter J. 22, 23, 24, 25, 26
  • Robson, Arthur J. 166
  • Ross, Marc Howard, 167
  • Rusciano, Frank Louis, 168
• S
  • Sagan, Carl, 169
  • Samuelson, Larry, 15, 83
  • Schaffer, Mark E. 170
  • Schopler, John, 85
  • Schubert, Glendon, 171
  • Schuessler, Rudolf, 172, 173
  • Sella, Gabriella, 174, 175, 176
  • Shaw, R. Paul, 177
  • Sigmund, Karl, 146, 147, 148, 149, 150, 178, 179
  • Simon, Herbert A. 180
  • Smillie, David, 181
  • Smith, J.Q. 204
  • Snidal, Duncan, 182
  • Sober, Elliott, 183, 184, 185, 186
  • Sobus, Jay, 70
  • Somit, Albert, 187
  • Sorin, Sylvain, 5
  • Soutchanski, Mikhail, 3
  • Spiro, David E. 188
  • Stanford, William, 93
  • Stanley, E. Ann, 189
  • Stein, Janice Gross, 190
  • Stout, Suzanne, 10
  • Swistak, Piotr, 191
• T
  • Taylor, M.F.J. 156
  • Tesfatsion, Leigh, 189
  • Tetlock, Philip E. 192
  • Tyson, Thomas, 193
• V
  • van de Kragt, Alphons J.C. 33, 42
  • Vanberg, Viktor J. 194
• W
  • Wade, Robert, 195
  • Wallis, Anthony, 105
  • Ware, Roger, 53
  • Warsh, David, 196
  • Weaver, Jim, 197
  • Weber, Steve, 198
  • Weesie, Jeroen, 163, 199, 200
  • Wilkinson, Gerald S. 201
  • Wilson, David Sloan, 49
  • Wippler, Reinhard, 200
  • Wong, Yuwa, 177
  • Wu, Jianzhong, 202
• Y
  • Young, H. Peyton, 203
  • Young, S.C. 204
• Z
  • Zagare, Frank C. 205, 206
  • Ziegler, Rolf, 207
  • Zuckerman, Diana, 208
  • Zupan, Mark A. 209

SUBJECT INDEX

to citation numbers

• A
  • Absolute gains, see Relative vs. absolute gains
  • Anthropology, see Sociology and anthropology
  • Automata theory, 3, 5, 15, 54, 81, 93, 111, 112, 121, 135, 139, 140, 144, 145, 155, 161, 179, 189
• B
  • Biological applications, 8, 28, 29, 32, 37, 39, 43, 46, 47, 48, 60, 62, 69, 72, 73, 74, 75, 76, 77, 84, 105, 106, 107, 110, 113, 125, 126, 127, 128, 130, 132, 133, 134, 141, 142, 147, 149, 156, 165, 166, 174, 175, 176, 178, 183, 201, 208
  • specific species:
    • ants, 156
    • baboons, 141, 142
    • bats, 125, 201
    • birds, 113
    • butterflies, 156
    • chimpanzees, 76, 77
    • impala, 72, 73
    • rhesus monkeys, 74
    • vervets, 75
    • worms, 174, 175, 176
  • Biological theory, see Biological applications; Theory
  • Business, see Economics and business
• C
  • Choices, 7, 40, 49, 85, 99, 106, 115, 121, 152, 159, 166, 189, 194, 209
  • Clustering, see Population structure, clustering
  • Collateral research, 32, 35, 36, 40, 45, 57, 73, 83, 102, 104, 116, 126, 136, 155, 160, 162, 168, 170, 171, 174, 176, 187, 199, 200, 208
  • Comparing different PD matrices, see Payoffs, comparing different PD matrices
• D
  • Deductive, 2, 5, 9, 11, 12, 14, 15, 16, 19, 20, 21, 23, 24, 25, 26, 35, 40, 53, 56, 57, 71, 79, 82, 83, 90, 91, 93, 96, 101, 102, 103, 106, 110, 114, 118, 119, 125, 126, 127, 130, 131, 132, 135, 138, 140, 146, 153, 155, 157, 158, 159, 163, 165, 166, 168, 170, 172, 173, 180, 182, 183, 185, 188, 191, 199, 200, 204, 206
  • Domestic law and politics, see Politics and law, domestic
• E
  • Economics and business, 2, 34, 52, 56, 68, 78, 79, 82, 83, 87, 88, 89, 98, 121, 151, 154, 166, 193, 195, 196, 200
  • Empirical, 4, 13, 16, 33, 36, 37, 42, 45, 50, 56, 58, 63, 64, 66, 82, 90, 92, 98, 100, 104, 108, 109, 122, 124, 151, 152, 154, 177, 193, 195; see also Biological applications, specific species
  • Endogenous ending, 26
  • ostracism, 79, 124, 125
  • voluntary exit, 85, 106, 115, 152, 194, 199
  • Enumerated set, see Limited set of allowable rules, enumerated set
  • ESS, see Population dynamics, ESS
  • Evolutionary theory, see Theory; Population dynamics
  • Exit, see Endogenous ending; Endogenous ending, voluntary exit
• F
  • Finite state machines, see Limited set of allowable rules, finite state machines
• G
  • Gains, see Relative vs. absolute gains
• I
  • Information requirements, see Population structure, information requirements
  • Interactions, 2, 3, 4, 7, 8, 11, 14, 22, 23, 26, 27, 33, 35, 37, 42, 48, 56, 60, 61, 64, 75, 76, 77, 79, 88, 91, 93, 102, 115, 121, 123, 124, 126, 137, 138, 141, 142, 144, 153, 157, 158, 168, 170, 173, 178, 179, 182, 195, 199, 200, 203, 207
  • International law and politics, see Politics and law, international
• L
  • Law, see Politics and law, domestic; Politics and law, international
  • Limited rationality, see Limited set of allowable rules, limited rationality
  • Limited set of allowable rules, 55, 118, 157
  • enumerated set, 13, 19, 20, 24, 47, 49, 64, 71, 80, 90, 91, 99, 100, 103, 107, 109, 120, 123, 139, 140, 144, 158, 169, 185, 186, 188, 189, 192, 194, 202, 203, 207
  • finite state machines, 3, 15, 59, 81, 93, 112, 121, 135, 144, 179
  • limited rationality, 5, 14, 15, 40, 70, 83, 90, 92, 93, 101, 112, 135, 180, 186, 200, 204, 206
  • parameterized rules, 41, 110, 111, 121, 125, 133, 143, 146, 147, 148, 149, 150, 155, 178, 204
• M
  • Miscellaneous, 27, 55, 95, 104, 117, 130, 131, 160, 162, 209
  • Misimplementation, see Noise, misimplementation
  • Misperception, see Noise, misperception
• N
  • n-person PD, see Interactions
  • Noise, 2, 7, 10, 11, 63, 99, 101, 108, 111, 147, 148, 150, 178, 203, 209
  • misimplementation, 9, 21, 26, 59, 71, 149, 202
  • misperception, 9, 14, 44, 56, 71, 192, 203
  • Norms, 1, 12, 14, 16, 38, 39, 79, 86, 101, 115, 136, 153, 169, 180, 190
• O
  • Ostracism, see Endogenous ending, ostracism
• P
  • Parameterized rules, see Limited set of allowable rules, parameterized set
  • Payoffs, 1, 2, 5, 7, 11, 12, 27, 34, 35, 40, 41, 48, 50, 51, 56, 59, 61, 64, 66, 67, 71, 74, 79, 80, 83, 90, 96, 102, 103, 107, 110, 113, 116, 122, 123, 125, 126, 127, 128, 129, 132, 134, 137, 141, 142, 144, 145, 147, 154, 159, 165, 166, 168, 170, 179, 182, 188, 192, 193, 198, 199, 204, 205, 206, 209
  • comparing different PD matrices, 9, 13, 14, 16, 19, 20, 31, 41, 42, 49, 54, 67, 79, 80, 90, 91, 92, 96, 103, 110, 112, 115, 121, 124, 145, 146, 166, 172, 207, 209
  • Players, see Interactions
  • Politics and law
  • domestic, 11, 27, 38, 39, 69, 97, 105, 117, 124, 136, 167, 168, 171, 173, 177, 180, 187, 195, 197, 207
  • international, 1, 6, 11, 13, 30, 31, 34, 37, 39, 44, 45, 50, 51, 63, 64, 65, 66, 67, 69, 90, 94, 95, 108, 109, 122, 136, 137, 153, 159, 164, 167, 177, 182, 187, 188, 190, 192, 198, 205, 206, 207
  • Population dynamics, 7, 19, 55, 80, 81, 84, 102, 130, 144, 161, 186
  • ESS, 9, 15, 17, 18, 20, 21, 23, 25, 26, 35, 43, 48, 49, 53, 54, 59, 60, 62, 71, 72, 91, 99, 101, 106, 110, 111, 112, 113, 114, 119, 121, 123, 125, 126, 127, 131, 132, 133, 138, 139, 140, 143, 146, 147, 148, 149, 157, 158, 165, 166, 170, 172, 173, 175, 177, 178, 183, 185, 191, 201, 203, 204
  • replicator dynamics, 14, 17, 21, 35, 59, 91, 111, 120, 138, 140, 143, 145, 148, 149, 157, 172, 179, 180, 202
  • Population size, 11, 12, 22, 26, 41, 61, 79, 85, 91, 115, 138, 158, 163, 172, 173, 189, 203
  • Population structure, 4, 7, 11, 19, 20, 23, 25, 35, 37, 39, 48, 61, 69, 75, 110, 126, 130, 152, 163, 180, 181, 183
  • clustering, 18, 22, 43, 62, 96, 116, 124, 139, 157, 166, 177, 179, 183, 201
  • information requirements, 8, 13, 14, 15, 29, 47, 49, 52, 56, 57, 70, 79, 96, 105, 115, 127, 135, 141, 158, 166, 174, 178, 189, 201
  • spatial models, 18, 60, 81, 115, 139, 144, 145, 150, 157, 179, 201, 207
  • Psychology, 10, 16, 32, 33, 37, 39, 42, 44, 45, 56, 57, 58, 85, 92, 96, 97, 116, 136, 152, 154, 180, 192, 199, 208
• R
  • Relative vs. absolute gains, 31, 50, 65, 66, 67, 137, 159, 170, 182, 190
  • Replicator dynamics, see Population dynamics, replicator dynamics
  • Reputation, 4, 12, 27, 56, 86, 94, 108, 122, 154, 163, 207
  • Rules, see Limited set of allowable rules
• S
  • Simulation, 3, 31, 41, 47, 48, 61, 64, 115, 150, 155, 188, 189, 194, 200; see also Population dynamics; Population dynamics, ESS; Population dynamics, replicator dynamics
  • Size, see Population size
  • Sociology and anthropology, 8, 11, 22, 25, 26, 32, 33, 36, 37, 39, 43, 47, 56, 57, 69, 70, 74, 79, 85, 86, 97, 101, 115, 124, 128, 129, 130, 141, 162, 163, 167, 169, 171, 173, 177, 180, 184, 195, 199, 200, 207
  • Spatial models, see Population structure, spatial models
  • Strategies, see Limited set of allowable rules
• T
  • TFT, see Limited set of allowable rules, enumerated set; Limited set of allowable rules, parameterized rules
  • Theory, 2, 5, 11, 12, 16, 22, 24, 29, 32, 40, 56, 57, 79, 93, 96, 97, 124, 135, 136, 142, 150, 152, 153, 155, 160, 162, 163, 168, 171, 181, 182, 184, 199, 200; see also Population dynamics; Population dynamics, ESS; Population dynamics, replicator dynamics
  • Tournament (with submitted rules), 6, 10, 120, 121, 188, 202
• V
  • Voluntary exit, see Endogenous ending, voluntary exit

University of Michigan Center for the Study of Complex Systems
Contact cscs@umich.edu.
Revised May, 1998.