I saw this interesting article that suggest monkeys have the same sense of unfairness that humans do.

it was an interesting read, displaying how a monkey who observed another monkey being treated better would get upset. The study had monkey’s trading granite tokens in for a treat. One would receive a cucumber slice, and the other a more tasty grape. It draws some connections between human sense of fairness and monkeys.

the last paragraph is funny though. She points out that the monkey who got the better deal didn’t care about the other monkey and implies that humans are better than that:

Brosnan, who said she is now conducting similar studies with chimpanzees, noted that the capuchin that got the grape didn’t react at all to the unjustness of the situation. That “probably implies there is still a lot of difference between their sense of fairness and ours,” she said.

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