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Kinship

15 February, 2016 - 10:55

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).

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

Table 8.1 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?

Table 8.1 Percentage of Genetic Material Shared by the Members of Each Category

Identical monozygotic twins

100%

Parents, children, siblings, and fraternal (dizygotic) twins

50%

Half-sibling, grandparent, and grandchild

25%

Cousins, great-grandchildren, great-grandparents, great-aunts, great-uncles

12.50%

Unrelated persons, such as a marital partner, brother-in-law or sister-in-law, adopted or step-sibling, friend, or acquaintance

0%

*Source: Neyer and Lang (2003).

 

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.