The study, published in Proceedings of the Royal Society B: Biological Sciences, tested whether reassuring body contact, such as embracing, touching and kissing, seen in bonobos and chimpanzees alike, improved social tolerance.

The results show that individuals who engaged in more reassuring touch before socially tense events like feeding subsequently spent more time co-feeding alongside others—indicating a direct link between pre-competition reassurance and peaceful resource sharing.

The researchers believe this shows that friendly touch may function as a flexible, short-term tool to manage social tension and competition, maintain social relationships and group harmony.

The close similarity in the types of reassurance behaviors between bonobos and chimpanzees suggests the practice has a common evolutionary origin, dating back at least 6 million years to the common ancestor shared by humans and our ape relatives.

How the team tested tension

To carry out the study, a team led by Durham University's Department of Psychology analyzed reassuring body contact before competitive feeding events among five semi-wild groups of bonobos and chimpanzees.

In total, 116 individuals were filmed during a controlled five-minute window before food was released into a shared, restricted space—a setup designed to mimic the social tension of natural resource competition, such as fruiting trees.