Great apes use touch to build trust before conflict, study finds

When food arrives, tension rises. The apes know it. They can feel it coming. And so, in the minutes before the peanuts appear, something happens that researchers at Durham University found both striking and oddly familiar: the apes reach for each other.

They touch. They embrace. They press their faces close. One ape will place a finger inside another's mouth—a gesture that seems impossibly intimate for creatures with a reputation for violence. And then, when the food finally comes, something shifts. The apes who had just reassured each other moments before are more likely to eat side by side without conflict. They share space. They share resources. The trust, it seems, was real.

This is what Zanna Clay and her team at Durham observed while studying chimpanzees and bonobos at sanctuaries in the Democratic Republic of Congo and Zambia. They designed an experiment that mimicked the natural feeding patterns these apes would encounter in the wild, using peanuts as the prize. For five minutes before the food arrived, researchers watched and recorded every instance of physical contact: the touches, the hugs, the kisses. They were looking for a pattern, and they found one.

The pattern was unmistakable. Groups that engaged in higher levels of reassuring touch—including what researchers called "reassurance trains," chains of apes embracing one another in succession—were measurably more cooperative when resources became scarce. The apes who had touched were the ones who could share. Clay described the behavior as "a rallying cry" before a stressful moment, the same impulse that sends a football team into a huddle before kickoff. "It's like a 'we' rather than a 'me'," she said. The physical contact seemed to shift something fundamental in how the apes related to one another.

What makes this finding remarkable is not just what it reveals about apes, but what it suggests about us. Jake Brooker, another researcher on the project, noted that social touch is among the oldest forms of communication known to exist—older than language, older than words. The team believes this behavior likely emerged at least seven million years ago, before humans, chimpanzees, and bonobos diverged from their common ancestor. That means every time a person hugs a friend before a difficult conversation, or pats a colleague on the shoulder before a presentation, or gathers in a huddle before something uncertain, they are drawing on a social toolkit that predates civilization itself.

The research, published in the Proceedings of the Royal Society B: Biological Sciences, offers a window into how our closest living relatives manage the fundamental tension between competition and cooperation. Food is scarce. Resources matter. Conflict is possible. And yet, before any of that unfolds, there is this: the reaching out, the touching, the simple act of reassurance. It is a reminder that some of our deepest instincts about how to be together—how to build trust, how to prepare for stress, how to transform "me" into "we"—are not modern inventions. They are ancient. They are written into our bodies. They are waiting to be used.