If a colleague of yours was rewarded for their work while you received nothing for your (similarly sized) efforts, you would probably be quite peeved. Now it seems that man’s best friend also shares our disdain for unfairness.

Humans are notorious for our dislike of injustice. It rankles us to see others being rewarded or penalised unfairly. We not only have the capacity to recognise when someone else is being rewarded beyond their efforts, but the inclination to punish them for it, often at personal expense. But other species behave in the same way – recent studies have found that capuchin monkeys and chimpanzees also have the ability to compare their payoffs and efforts to those of their peers, and