Chimps Value Fair Play

Studies with apes and monkeys show that the concept of fairness goes beyond human experience. Researchers taught monkeys and chimpanzees to exchange tokens for grapes (which they preferred) or carrots. The exchanges went well when the subject knew what to expect, and when the reward they bought was the same for their cohorts. But when the researcher offered a grape and then delivered a carrot, or when the subject got a different reward from his cohorts, the tantrums began.

However, chimpanzees in this study went beyond the basic tenets of the social contract and demonstrated what could be considered the foundation of social solidarity. In 95 trials chimpanzees that received a grape were significantly more likely to refuse the high-value reward when their group mate only received a carrot (p = 0.008). Even those who benefitted from inequality recognized that the situation was unfair and they refused to enjoy their own reward if it meant someone else had to suffer.

This particular behavior was not seen in the monkeys. Did a sense of fairness evolve along with cooperation among higher primates? Link

(image credit: Flickr user Owen Booth)