Chimpanzees and bonobos use physical contact to reassure one another before stressful situations, according to research reported by BBC News.
Scientists at Durham University studied the behaviour of the great apes at sanctuaries in the Democratic Republic of Congo and Zambia. The research focused on how the animals interacted before expected competition over food.
The team created an experiment intended to resemble natural feeding, using peanuts. Researchers watched the apes during the five minutes before the food arrived, when the animals appeared to know it was coming, and recorded reassuring contact such as touching, embracing and kissing.
Prof Zanna Clay said the apes came together before stressful events, touching and hugging in a way she compared to a team huddle before a major match. One notable finding was that chimpanzees, despite being known for aggression, showed close contact that included placing fingers in another ape’s mouth.
The researchers found that apes who touched and embraced were more likely to reach food and eat near each other peacefully. Groups that were more tolerant showed greater levels of reassuring touch, including sequences in which several apes embraced one another in turn.
Dr Jake Brooker said comparing chimpanzees and bonobos, humans’ two closest relatives, offered insight into the evolutionary origins of social behaviour and the management of tension, competition and cooperation. He said social touch was among the oldest forms of communication and probably came before language.
The researchers suggest that using touch to build trust and cooperation may go back at least seven million years, before humans, chimpanzees and bonobos diverged from a common ancestor. The study was published in Proceedings of the Royal Society B: Biological Sciences.
