Primate Morality
Frans de Waal has found that consolation is universal among the great apes but generally absent from monkeys — among macaques, mothers will not even reassure an injured infant.
Every species of ape and monkey has its own protocol for reconciliation after fights. If two males fail to make up, female chimpanzees will often bring the rivals together. Or they will head off a fight by taking stones out of the males’ hands.
Macaques and chimpanzees have a sense of social order and rules of expected behavior, mostly to do with the hierarchical natures of their societies, in which each member knows its own place. Young rhesus monkeys learn quickly how to behave, and occasionally get a finger or toe bitten off as punishment. Chimps are more likely to share food with those who have groomed them. Capuchin monkeys show their displeasure if given a smaller reward than a partner receives for performing the same task, like a piece of cucumber instead of a grape.
“Scientist Finds the Beginnings of Morality in Primate Behavior,” by Nicholas Wade