The researchers suggest that capuchin monkeys, like humans, are guided by social emotions.In the wild, they are a co-operative, group-living species.

• 每个人都喜欢大幅加薪，但是如果你知道你同事薪水涨得比你多，那么恐怕加薪带给你的喜悦感就会烟消云散了。