A pair of capuchin monkeys show very compelling signs of cooperation and a sense of fairness, by working together to solve a problem using tools, and then sharing the reward.
They also show signs of understanding fairness: when unequal rewards are given to one monkey and not another, the monkey receiving the lesser treat would rather go hungry than accept anything less than an equal reward.
From the BBC documentary “Capuchins: The Monkey Puzzle”, narrated by the ever brilliant Sir David Attenborough.
* * *
* * *