Some Thoughts on the Adaptive Function of Inequity Aversion: An Alternative to Brosnan’s Social Hypothesis

In this commentary, we review and question Brosnan's hypothesis that inequity aversion (IA) evolved as a domain-specific social mechanism. We then outline an alternative, domain-general, account of IA. As opposed to Brosnan's social hypothesis, we propose that IA evolved from more general reward mechanisms. In particular, we argue reference-dependence and loss-aversion can account for the evolution of IA in primates. We discuss recent work on reference-dependence and explore how it may have given rise to inequality-averse behavior in social settings. We conclude with suggestions for future work examining the proximate mechanisms that give rise to IA. Reprinted by permission of Springer