The prosocial primate - A critical review

The problem of cooperation has long been a central issue in evolutionary biology and psychology, although these disciplines approach the problem from different directions. In little over a decade, there have been great advances in experiments that bridge the psychological and evolutionary domains. By testing nonhuman primates, this work is trying to determine the phylogenetic roots of human sociality and the cognitive structures that scaffold this transition. In trying to understand prosocial behavior which is motivated for the welfare of others, researchers need to be aware of look-alikes. There are numerous examples of behaviors that appear prosocial, but are performed for the actor's benefit with any benefits to others arising as unintended by-products. Observations of natural behavior are suggestive, but experiments are needed to tease apart the alternative explanations. Even with experiments, it is challenging to interpret the findings. In this review, I critically discuss the experimental studies that have been designed to test for prosocial behavior in nonhuman primates. It is too early to conclude from these studies that chimpanzees and other nonhuman primates share with humans the motivation to share and help. Humans may be the only prosocial primate.