Barclay, P. & Van Vugt, M. (2015). The Evolutionary Psychology of Human Prosociality: Adaptations, Byproducts, and Mistakes.
In D. Schroeder and B. Graziano, Handbook of Prosocial Behavior. (pp. 37-60) Chapter 2: Oxford University Press.
Evolutionary psychologists seek to understand prosocial behavior at four complementary levels of analysis: psychological mechanisms, development of those mechanisms (ontogeny), their adaptive or evolutionary function, and their evolutionary history (phylogeny). In terms of adaptive function, prosocial behavior is often costly to perform, so it is an evolutionary enigma. To evolve and be maintained, prosocial sentiment needs to bring corresponding fitness benefits. The authors outline a number of such evolutionary functions of prosocial behavior. Adaptive functions include direct benefits, mutualisms, stake or vested interests, kinship, reciprocity (direct and indirect), and costly signaling. Nonadaptive functions include mistakes, byproducts, and cultural learning. They provide a diagnostic tool for determining the likely function of any particular prosocial act and discuss three emerging perspectives in the study of prosocial behavior: scale of competition, multilevel selection, and biological markets. We conclude with future directions in evolutionary research on prosocial behavior.
Key Words: altruism, cooperation, reciprocity, costly signaling, evolutionary psychology, levels of analysis