This study focuses on whether or not Hamilton’s rule applies to humans. Hamilton’s rule suggests that individuals are more likely to altruistically help closer kin and, in turn, receive altruistic help from the same kin. While this rule has been well supported in animal subjects, data on humans has been lacking. Testing for altruism without causing any serious risk to participants proved difficult in many of the previous studies.
Taking a different approach, Burton-Chellew et al. conducted an anonymous online survey, which allowed them to survey participants’ support networks, as well as the genetic relatedness within those networks, inferring that alters in the support network would be most likely to altruistically help the ego of the network. This survey also gathered information on participants’ emotional closeness to each person named in their networks. For the most part, participants in the survey felt that their closest relatives were most supportive (see Figure 3). A sizable exception to this trend, however, was caused by participants listing their romantic partners as the most supportive people in their networks. In general, emotional closeness was directly related to the perceived supportiveness of each member in the network (see Figure 2). While the data supports Hamilton’s rule, a large portion of the alters listed in the support networks were nonrelatives, which cannot be explained by Hamilton’s rule. Therefore, further research could look into why certain nonrelatives express this “helping behavior.” The researchers neglected to ask for the nationality of their participants in the online survey, so these results may vary cross-culturally.
The full article can be found here.
Burton-Chellew, M. N., & Dunbar, R. I. M. (2015). Hamilton's rule predicts anticipated social support in humans. Behavioral Ecology, 26(1), 130–137. doi:10.1093/beheco/aru165