" If you now ask me if there is any difference between the human sense of fairness and that of chimpanzees, I really don’t know anymore. There are probably a few differences left, but by and large both species actively seek to equalize outcomes. The great step up compared with the first-order fairness of monkeys, dogs, crows, parrots, and a few other species is that we hominids are better at predicting the future. Humans and apes realize that keeping everything for themselves will create bad feelings. So second-order fairness can be explained from a purely utilitarian perspective. We are fair not because we love each other or are so nice but because we need to keep cooperation flowing. It’s our way of retaining everyone on the team. "

― Frans de Waal , Mama's Last Hug: Animal Emotions and What They Tell Us about Ourselves