CHIMPS recognise unfairness, even when it involves individuals other than themselves. This sense of unfairness towards others may be a rudimentary form of the social justice that characterises human societies.
In earlier studies several apes, monkeys and even dogs responded negatively when they received a meagre reward for the same task that earned others a more lavish pay-off. But none of these animals apparently recognised unfairness directed at others.
, a primate behaviourist at Georgia State University in Atlanta, and her colleagues trained captive chimps to exchange tokens for a food reward, then tested how same-sex pairs of chimps reacted to various levels of reward. As expected, chimps were more likely to reject a boring carrot when their partner got a yummy grape for the same token. Surprisingly, the chimps were also more likely to reject a grape if their partner only got a carrot (Animal Behaviour, ).
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In previous experiments, other groups of chimps showed no sensitivity towards unfairness directed at others. Perhaps Brosnan鈥檚 animals rejected their 鈥渦ndeserved鈥� grapes in part because they sat right next to their less fortunate partner and may have feared retaliation for their windfall, the researchers suggest.
But the chimps鈥� awareness of the mistreatment of others as well as themselves also lays the groundwork for complex social interactions more like those of human groups, they note.
