Do you know why chimpanzees hug and kiss?

Prof. Know Why answers for your general knowledge and awareness on: Do you know why chimpanzees hug and kiss?

In humans, a nice hug and some sympathy can normally help a bit after we get pushed around. Now, it’s known that chimpanzees also use hugs and kisses the same way. And it works! Researchers studying human's closest genetic relatives, the chimpanzees, found that stress was reduced in chimpanzees who were victims of aggression if a third chimpanzee stepped in to offer consolation.

The findings were reported recently in the Proceedings of the National Academy of Sciences. The research was done by Dr. Orlaith N. Fraser of the Research Center in Evolutionary Anthropology and Paleoecology at Liverpool John Moores University in England; and colleagues. They studied chimpanzees at the Chester Zoo in England from January 2005 to September 2006, recording instances of aggression such as a bite, hit, rush, trample, chase or threat.

Dr. Fraser said that the research showed, "consolation usually took the form of a kiss or embrace", which is particularly interesting because this behavior is rarely seen other than after a conflict. "If a kiss was used, the consoler would press his or her open mouth against the recipient's body, usually on the top of the head or their back. An embrace consisted of the consoler wrapping one or both arms around the recipient."

The result was a reduction of stress behavior among the chimpanzees, such as scratching or self-grooming by the victim of aggression, reported Dr. Fraser and colleagues.

Dr. Frans de Waal of the Yerkes Primate Center at Emory University in Atlanta, who was not part of Fraser's research team, said, the study is important because it shows the relationship between consolation and stress reduction in the chimpanzees.

"This study removes doubt that consolation really does what the term suggests: provide relief to distressed parties after conflict. The evidence is compelling and makes it likely that consolation behavior is an expression of empathy," Dr. Waal said.

Dr. Waal suggested that this evidence of empathy in chimpanzees is "perhaps equivalent to what in human children is called 'sympathetic concern.'"

That behavior in children includes touching and hugging of distressed family members and "is in fact identical to that of apes, and so the comparison is not far-fetched," he said. But, while chimpanzees show this empathy, monkeys do not, he added.

Previous research on conflict among chimpanzees concentrated on cases where there were reconciliation between victim and aggressor, with little attention to intervention by a third party.

The latest research result shows that chimpanzees calm distressed recipients of aggression by consoling them with a friendly gesture. But, consolation is most likely to occur, that is by hugs and kisses, between chimpanzees who already have valuable relationships, concludes chief researcher Dr. Orlaith N. Fraser.

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