Besides the enormous amount of anecdotal evidence that animals behave altruistically, both toward members of their own species and also to animals outside their species, there is clinical evidence as well, such as the typically cruel experiments in which monkeys were given food if they administered painful shocks to other monkeys.

Researchers found that the monkeys would rather go hungry than shock other monkeys, especially if they had received shocks earlier themselves. The researchers were surprised (and perhaps somewhat ashamed?) by the monkeys’ altruism. Though it is our true nature, one wonders if we humans would be so noble.