Researchers at the Yerkes National Primate Research Center have shown chimpanzees have a significant bias for prosocial behavior.
The authors say this study puts to rest a longstanding puzzle surrounding chimpanzee altruism. It is well-known these apes help each other in the wild and show various forms of empathy, such as reassurance of distressed parties. The negative findings of previous studies did not fit this image. These results, however, confirm chimpanzee altruism in a well-controlled experiment, suggesting human altruism is less of an anomaly than previously thought.