SEARCH

SEARCH BY CITATION

Keywords:

  • inequity aversion;
  • social cognition;
  • prosocial behavior;
  • other regarding preferences;
  • fairness

Abstract

Recent studies have produced mixed evidence about inequity aversion in nonhuman primates. Brosnan et al. [Proceedings of the Royal Society of London. Series B. Biological Sciences 272:253–258, 2005] found inequity aversion in chimpanzees and argued that effort is crucial, if subjects are to evaluate how they are rewarded in comparison to a competitor for an identical performance. In this study we investigated inequity aversion with chimpanzees, bonobos and orangutans, using the method of Brosnan et al. [Proceedings of the Royal Society of London. Series B. Biological Sciences 272:253–258, 2005] after introducing some methodological improvements. Subjects always received a less-preferred food in exchange for a token, whereas the competitor received either the same type of food for their token (equity) or a more favored food for it (inequity). Apes did not refuse more of the less-preferred food when a competitor had received the more favored food. Thus, with an improved methodology we failed to reproduce the findings of Brosnan et al. [Proceedings of the Royal Society of London. Series B. Biological Sciences 272:253–258, 2005] that apes show inequity aversion. Am. J. Primatol. 71:175–181, 2009. © 2008 Wiley-Liss, Inc.