Social preferences in primates

To investigate the nature of social preferences in primates, researchers have recently devised a series of experiments in which animals are presented with opportunities to provide benefits to others at little or no cost to themselves. The choices that they make in these experiments provide insight about their social preferences. Although the discrepancy between the results obtained in experiments that were designed to examine chimps' social preferences may seem like an unfortunate complication, it provides with an important opportunity. If one can work out the reasons why the results of these experiments differ, one may gain deeper insights about the complexity and nature of chimps' social preferences. For example, the presence of food rewards might compete with selfish motives about food. If that is the case, then the chimps who were indifferent in the Silk/Jensen/Vonk experiments might behave prosocially in the protocol used by Warneken and his colleagues, and vice versa.