Chimp Cure For Stress: Hugs And Kisses
Researchers studying chimpanzees have found that stress is reduced in chimpanzees that are victims of aggression if a third chimpanzee steps in to offer consolation. This shows a relationship between consolation and stress reduction, an expression of empathy which is equivalent to “sympathetic concern” in human children.
Chimpanzees calm distressed victims of aggression by consoling them with a friendly gesture. This consolation was most likely to occur between chimpanzees who had previously established valuable relationships. Similar behavior is shown among children who touch and hug distressed family members.
While chimpanzees show this empathetic behavior, monkeys generally do not. According to this article, there is also evidence of this empathetic behavior in large-brained birds and dogs.