Chapter 2 Reciprocal Altruism in Primates. Partner Choice, Cognition, and Emotions

Abstract

This paper reviews recent work on reciprocal altruism in primates with the aim of highlighting the roles that reciprocal partner choice may have had in the evolution of primate altruism, and that emotions may play in supporting primates' ability to exert such reciprocal partner choice. Individual studies and meta-analyses show that primates reciprocate a variety of behaviors that benefit other individuals (be they altruistic or mutualistic). These behaviors include grooming, agonistic support, and food sharing. Analyses of the time frame of these reciprocal exchanges suggest primates deploy their altruistic behaviors among group mates on the basis of long-term accounts of altruism received, and are thus not constrained to immediate reciprocation. We argue that a system of emotional bookkeeping of benefits received may be at the basis of primate reciprocation. This hypothesis is consistent with behavioral data and with our current knowledge about primate cognitive abilities and the neurobiological correlates of affiliative behaviors. Investigations of the role that emotions play in the social life of primates may help us bridging the gap between the apparent complexity of their social life and the relative simplicity of their cognitive abilities. © 2009 Elsevier Inc. All rights reserved.