Kinship

Is the tendency to help others, at least in part, a basic feature of human nature? Evolutionary psychologists believe so. They argue that although helping others can be costly to us as individuals, altruism does have a clear benefit for the group as a whole. Remember that in an evolutionary sense the survival of the individual is less important than the survival of the individual’s genes (McAndrew, 2002). Therefore, if a given behavior such as altruism enhances our reproductive success by helping the species as a whole survive and prosper, then that behavior is likely to increase fitness, be passed on to subsequent generations, and become part of human nature.

If we are altruistic in part to help us pass on our genes, then we should be particularly likely try to care for and to help our relatives. Research has found that we are indeed particularly helpful to our kin (Madsen et al., 2007; Stewart-Williams, 2007). Burnstein, Crandall, and Kitayama (1994) asked students in the United States and Japan to report how they would respond to a variety of situations in which someone needed help. The students indicated that in cases in which a person’s life was at stake and the helping involved a lot of effort, time, and danger, they would be more likely to help a person who was closely related to them (for instance, a sibling, parent, or child) than they would be to help a person who was more distantly related (for example, a niece, nephew, uncle, or grandmother). People are more likely to donate kidneys to relatives than to strangers (Borgida, Conner, & Manteufel, 1992), and even children indicate that they are more likely to help their siblings than they are to help a friend (Tisak & Tisak, 1996).

Figure 8.3 We are particularly helpful to people who share our genetic background.

Table 8.1, “Percentage of Genetic Material Shared by the Members of Each Category,” shows the average extent to which we share genes with some of the people we are genetically related to. According to evolutionary principles, this degree of genetic closeness should be positively correlated with the likelihood that we will help each of those people. Do you think that your own likelihood of helping each of the people listed corresponds to the degree to which you are genetically related to that person?

Our reactions to others are influenced not only by our genetic relationship to them but also by their perceived similarity to us. We help friends more than we help strangers, we help members of our ingroups more than we help members of outgroups, and we are even more likely to help strangers who are more similar to us (Dovidio et al., 1997; Krupp, DeBruine, & Barclay, 2008; Sturmer, Snyder, Kropp, & Siem, 2006). It is quite possible that similarity is an important determinant of helping because we use it as a marker—although not a perfect one—that people share genes with us (Park & Schaller, 2005; Van Vugt & Van Lange, 2006).  Cialdini, Brown, Lewis, Luce, and Neuberg (1997) have proposed that it is the sense of perceived similarity—the sense of ‘‘oneness’’ between the helper and the individual in need—that motivates most helping.

Reciprocity and Social Exchange

Although it seems logical that we would help people we are related to or those we perceive as similar to us, why would we ever help people to whom we are not related? One explanation for such behavior is based on the principle of reciprocal altruism (Trivers, 1971). Reciprocal altruism [Production: Please bold font in OER] is the idea that if we help other people now, they will return the favor should we need their help in the future. Thus by helping others, we both increase our chances of survival and reproductive success and help others increase their chances of survival too. Over the course of evolution, those who engage in reciprocal altruism should be able to reproduce more often than those who do not, thus enabling this kind of altruism to continue. Reciprocal altruism means that people even may help total strangers, based on the assumption that doing so is useful because it may lead others to help them (when help is most needed) in the future.

One fact that might help convince you that altruism is in fact evolutionarily adaptive is that many animals also engage in reciprocal altruism. Birds emit an alarm to nearby birds to warn them of a predator even at a potential cost to themselves. Dolphins may support sick or injured animals by swimming under them and pushing them to the surface so they can breathe. Male baboons threaten predators and guard the rear of the troop as it retreats. And even bats have a buddy system in which a bat that has had a successful night of feeding will regurgitate food for its less fortunate companion (Wilkinson, 1990).

Altruism can even be found in low-level organisms, such as the cellular slime molds (Figure 8.4, “Altruism”). Slime molds are groups of cells that live as individuals until they are threatened by a lack of food, at which point they come together and form a multicellular organism in which some of the cells sacrifice themselves to promote the survival of other cells in the organism. Altruism, then, is truly all around us.

Figure 8.4 Altruism is found in many organisms including even cellular slime molds (upper right).

Reciprocal altruism is one example of the general principle of social exchange [Production: Please bold font in OER]. We frequently use each other to gain rewards and to help protect ourselves from harm, and helping is one type of benefit that we can provide to others. In some cases, this exchange reflects overt cooperation, such as when two students take notes for each other in classes that they miss or when neighbors care for each other’s pets while one of them is away. In other cases, the exchange may be more subtle and indirect: for instance, when we help someone we don’t really know, with the expectation that someone else may help us in return someday.