Why would anyone need “a growing body of evidence that humans are remarkably altruistic primates”? In a peaceful and prosperous society, one sees instances of altruism as well as its opposite every day. And, given most humans’ preference for peace and prosperity, we should just assume that we are acting most naturally when we can live that way. Anyway,
A growing body of evidence shows that humans are remarkably altruistic primates. Food sharing and division of labor play an important role in all human societies, and cooperation extends beyond the bounds of close kinship and networks of reciprocating partners. In humans, altruism is motivated at least in part by empathy and concern for the welfare of others. Although altruistic behavior is well-documented in other primates, the range of altruistic behaviors in other primate species, including the great apes, is much more limited than it is in humans. Moreover, when altruism does occur among other primates, it is typically limited to familiar group members—close kin, mates, and reciprocating partners. This suggests that there may be fundamental differences in the social preferences that motivate altruism across the primate order, and there is currently considerable interest in how we came to be such unusual apes. A body of experimental studies designed to examine the phylogenetic range of prosocial sentiments and behavior is beginning to shed some light on this issue. In experimental settings, chimpanzees and tamarins do not consistently take advantage of opportunities to deliver food rewards to others, although capuchins and marmosets do deliver food rewards to others in similar kinds of tasks. Although chimpanzees do not satisfy experimental criteria for prosociality in food delivery tasks, they help others complete tasks to obtain a goal. Differences in performance across species and differences in performance across tasks are not yet fully understood and raise new questions for further study.- See Silk, J. B., and House, B. R., Evolutionary foundations of human prosocial sentiments (PNAS Early Edition, 2011/06/16/)
What’s fundamentally wrong with all these “how such-and-such a widespread custom originated” theses is that they do not exist to explain the custom; they exist to map its origin onto neo-Darwinist ideology. That’s what “explain” amounts to these days, and the staggering lack of resulting insight can fairly be taken as an assessment of neo-Darwinian theory itself.
Hat tip: Dave Coppedge.
Denyse O’Leary is co-author of The Spiritual Brain.