Kinship has been virtually ignored in psychology, social psychological studies are typically based on the interactions of strangers. When close relationships are studied, they tend to be dating and marital relationships, with a secondary emphasis on friendships (Daly, Salmon & Wilson, 1997). Sociobiological studies have found that in situations of cooperative behavior exchange, brothers tolerate imbalances of reciprocity that would be considered exploitive and unacceptable in friendship not based on kinship (Hames, 1988). Even in a relatively non-kin based society such as our own, people turn to close relatives when in need, and are increasingly likely to do so the greater the imposition or demand (Hogan & Eggebeen, 1995).
Many social psychologists are concerned whether or not "true altruism" exists, possibly to justify an evaluative judgment of the human species. Altruist advocates define altruism as "a motivational state with the ultimate goal of increasing another's welfare," (Batson, 1991 p. 6). The distinction between self and other is confounded when one considers benefits at the genetic level. Hamilton's inclusive fitness theory undermines the distinction between individuals, since "self-interest" can lie outside of one's body and inside the skin of another who shares a high percentage of genetic information. This difference in definition may not be resolved easily since altruist advocates and evolutionary theorists also differ in the unit of analysis.
For example, altruist advocates cite the example of a mother rushing to help her injured child. To an evolutionary theorist, this is an obvious case of kin selection (Kenrick, 1991). Altruist advocates admit that evolutionary theorists have been useful in revealing how self-sacrificial behavior can be consistent with the theory of natural selection, however they are more concerned with the driving mental motivation of the helper (Batson, 1991). Research supporting the evolutionary perspective, on the other hand, does not need to identify the cognitive mechanisms which drive the individual's behavior, so long as this motivation leads to successful kin selection.
The main distinction between the two perspectives is the definition of who or what is assisted. For the altruist advocate, that entity is another individual. An evolutionary theorist would consider the genetic information in that individual (which may be similar to that of the donor's) the ultimate benefactor. Consistent with evolutionary theory, felt oneness could arise as a consequence of attachment-related cues (kinship, friendship, familiarity) that signal relatively high genetic commonality. At the same time, an action that benefits the genes could be "altruistic" in terms of the cost to the helping individual. It is possible that the mechanism through which helping operates is the experience of empathy for another. From an evolutionary perspective, all common human motivational states would have, on average, served to increase the survival of our ancestor's individual genes (Kendrick, 1991).
In typical everyday situations, the influence of genetic relatedness is undoubtedly less than that of culturally transmitted information. Help to and from friends is usually expected to be more common than help among kin. However, specific predictions based on kin selection have received support. In a study of middle class Caucasian women in Los Angeles, Essock-Vitale & McGuire (1985) found that (a) helping among friends was more likely to be reciprocal than helping among kin, (b) closer kin were more likely sources of help than were more distant kin, (c) helping was an increasing function of the recipient's expected reproductive potential, and (d) the larger the amount of help given, the more likely it was to come from kin. Childless individuals might be expected to give more help to their nieces and nephews than would those with children, and this was found to be the case. Also, these childless aunts received more help from nieces and nephews. This data on relative assistance suggests that individuals maximize their inclusive fitness.
Most altruism studies in social psychology involve helping directed toward unrelated strangers. It has been suggested that empathy manipulations might trigger a mechanism that causes the subject to think of the victim as a fellow-that is belonging to the same group. It is surprising that social psychologists have not focused more on manipulations of genetic relatedness when studying altruism (Kendrick, 1991).
In studies conducted by Cialdini, Brown, Lewis, Luce & Neuberg (1997), it was found that as relationship closeness increased, so did empathic concern for a needy other. The amount of helping which was costly to the donor decreased with an increasing distance of relationship. That is, helping a family member was more likely than helping a close friend, which was more likely than helping an acquaintance, which was more likely than helping a near stranger. Rushton (1991) estimated that 71% of the variance in the amount of empathy in a set of altruism studies (Matthews, Batson, Horn & Rosenman, 1981) was accounted for by genetic relationship.
Burnstein, Crandall and Kitayama (1997) have published one of the few papers on helping intentions that takes evolutionary considerations into account. The first experiment asked respondents to rate how closely related they were to biologically close and distant kin, as well as non-kin, on a scale of 0 (completely unrelated) to 100 (extremely closely related). The results indicated that the drop in perceived relatedness between each target was significant, and that the largest difference was between close kin (r =.5) vs. moderately close kin (r = .25) and between distant kin (r = .125) vs. non-kin (r = .00). The authors also conducted a series of experiments using a forced choice between targets, and assistance scenarios with life-or-death consequences as well as everyday helping behaviors. Everyday helping behaviors showed equal intervals of decline across targets of decreasing relatedness, while intentions to assist for life-or-death scenarios mirrored the pattern found in perceived relatedness. An evolved mechanism for kin-selective helping would be important in emergencies, rather than everyday helping behaviors or those typically examined in laboratory studies (Kendrick, 1991).
Burnstein, Crandall and Kitayama (1997) also found that respondents were more likely to help kin with poor health in everyday situations, but kin with good health in life-or-death situations. Respondents were also more likely to help poor kin in everyday situations but wealthy kin in life-or-death situations. These results indicate that respondents selectively chose to assist those recipients who were likely to enhance fitness.
Helping behaviors based on kin recognition may also be influenced by the social conventions of relationship status (Hawkes, 1983). Proximity to and familiarity with individuals developed as a kin recognition cue since as people usually lived with or near their relatives in the ancestral environment. In industrialized nations today, family members are much more likely to disperse. The geographical distances of family members may have an effect on relationship judgments of moderately distant relatives, such as those in Burnstein, Crandall and Kitayama's (1997) study, where moderately distant relatives were judged to be more distant relative to actual genetic similarity. In the modern world, non-relatives may be taking the place of relatives in the social environment. This may lead one to predict diminished kin-selection behaviors for moderately distant relatives.
When considering assistance behaviors with non-relatives, an evolutionary perspective would focus on variables like the target's age and reproductive potential. One would expect to find relatively high helping, for instance, towards someone that is old enough to reproduce, but young enough to have a good number of remaining reproductive years (Kendrick, 1991). Burnstein, Crandall and Kitayama (1997) found that respondents were more likely to help infants and the elderly in everyday situations but were more likely to save young targets (1, 10 and 18 years) than older targets (45 and 75 years) in life-or-death situations. Under famine conditions, respondents were more likely to save 10 and 18 year olds than those in the other age categories. In decisions related to critical assistance, a non-relative's reproductive potential would take on a different importance if that non-relative was a potential mate, and would be a liability if the non-relative is a mating competitor (Kendrick, 1991).