Chimpanzees and Bonobos Use Hugs, Kisses and Friendly Pats to Keep the Peace, Just Like Humans, a New Study Suggests

New observations of bonobos and chimpanzees suggest that gestures familiar in human social life may also help other great apes navigate fraught moments. Researchers report that animals living in semi-wild settings embraced, clasped hands and gave gentle pats when circumstances were tense. The study, published July 22 in Proceedings of the Royal Society B, raises the possibility that affiliative contact can lower strain within a group before it develops into open conflict.

The finding places a commonplace human behavior in a broader evolutionary frame. People use a hug, handshake, high five or fist bump for many reasons: to offer reassurance, mark cooperation or renew a relationship. The new work indicates that close relatives may likewise use non-aggressive bodily contact as part of social management. Rather than treating touch only as an intimate or ceremonial human custom, the results point to its possible role in maintaining day-to-day stability among apes.

Chimpanzees and bonobos are especially informative comparisons because both are closely related to humans, while their social lives are not identical. The observations included kissing as well as hugging, hand-holding and light patting, showing that the relevant behavior was not limited to one gesture. In chimpanzee groups, males were more often involved in friendly contact with other males. That pattern suggests that the value of touch may depend on particular relationships and the social setting, not simply on an animal’s general willingness to be near another.

The authors’ interpretation is that these exchanges can help manage a difficult emotional moment. “Physical closeness” can be a powerful means of handling stress, said Zanna Clay, a primatologist at Durham University and a co-author of the research. In practical terms, a brief peaceful interaction could signal tolerance or reduce uncertainty between nearby animals. If that effect occurs reliably, it could make escalation less likely and help groups remain cohesive when pressure is high.

The study’s wording is important: the evidence supports a possible tension-reducing role, rather than demonstrating that every hug or pat prevents a fight. Social behavior can serve more than one purpose, and an observed touch does not by itself reveal exactly what each animal experienced or what would have happened without it. Because the animals were studied in semi-wild conditions, the findings are most directly grounded in those observed settings. The report therefore adds evidence about an association during stressful situations while leaving room for research into the precise pathways from contact to calmer behavior.

Its evolutionary implication is also suggestive rather than conclusive. Humans, chimpanzees and bonobos trace back to an ancestral lineage that existed roughly six to eight million years ago. Similar peaceful touching across the three living ape species may mean that the foundations of such behavior are ancient. But the study cannot directly watch that long-vanished ancestor, so the shared history is an inference drawn from the resemblance among its descendants.

That possibility matters because conflict avoidance is not only about the absence of aggression. In socially complex groups, individuals must repeatedly decide how to approach allies, rivals and uncertain partners. A small gesture of friendliness may help preserve access, trust or tolerance after a stressful episode. Seen this way, touch is not merely a response to tension; it may be one of the tools through which a community continually repairs the conditions for coexistence.

The next question is how broadly the pattern holds and when it has its strongest effect. Further work could compare different social relationships, kinds of stress and outcomes after contact, including whether hostility becomes less common. It could also help clarify why male chimpanzees showed a greater tendency toward male-to-male friendly touch in these observations. For now, the research offers a focused reminder that the social uses of a hug, kiss or reassuring pat may have roots far deeper than human custom.

Source: Smithsonian Magazine