How do great apes manage social stress and keep the peace?

Credit: Zac Mills, the Wildlife Collective

Historically, scientists studied how apes comfort each other after a fight – as a way to release tension and “make up” with each other. Now, researchers have studied how apes exchange hugs, kisses, and gentle touches before stressful events even begin. Almost like having a pre-match huddle before a football match: a reminder that they’re on the same team.

Researchers observed 116 chimpanzees and bonobos across five groups at sanctuaries. When a bamboo trough was filled with peanuts, there was a 5-minute window of high anticipation among the apes before the food was released. Scientists recorded all pre-feeding behaviours, such as patting, embracing, and mouth-to-body contact.

The results were clear: apes who engaged in more reassuring touch in the minutes before feeding were more likely to share the feeding area peacefully alongside others. In bonobos, female–female pairs were the most likely to engage in pre-feeding reassurance. In chimps, male–male pairs showed the highest levels of friendly touch before feeding.

One of the most striking discoveries was high-risk, trust-building behaviors in chimpanzees — such as placing fingers or hands inside another chimp’s mouth.

Interestingly, this behaviour only worked in socially tolerant groups. In groups with strict, authoritarian leaders, the pattern disappeared. Humans, bonobos, and chimpanzees all use reassuring touch to manage social tension. This is a reminder that using friendly touch to maintain social harmony is an ancient strategy rooted in our shared evolutionary history.