Full Breakdown
Physical Touch Helps Bonobos and Chimpanzees Avoid Conflict, New Study Shows
7/22/2026, 10:46:33 AM
Study Overview
Researchers from Durham University’s Department of Psychology examined whether reassuring physical contact—such as embracing, patting, kissing, and even mouth-to-body gestures—affects social tolerance in bonobos (*Pan paniscus*) and chimpanzees (*Pan troglodytes*). The peer-reviewed paper, published in *Proceedings of the Royal Society B: Biological Sciences* on July 22, 2026, reports that individuals who engaged in more touch during a five-minute anticipation period before food was released subsequently spent significantly more time co-feeding peacefully.
Methodology and Findings
- Subjects and setting: 116 apes from five semi-wild groups were filmed at two African sanctuaries—Lola ya Bonobo Sanctuary in the Democratic Republic of Congo and Chimfunshi Wildlife Orphanage Trust in Zambia.
- Experimental design: Researchers used a “peanut swing” feeding task that mimics natural competition for fruit. Food was released into a confined area after a five-minute pre-feeding window, during which all physical interactions were recorded.
- Key results: Across 60 co-feeding sessions (over 10 hours of observation), higher rates of pre-feeding touch correlated with longer periods of peaceful co-feeding. The effect was strongest in the most socially tolerant groups. Within species, female-female pairs showed the strongest association in bonobos, reflecting female alliance dynamics; male-male pairs showed the strongest association in chimpanzees, reflecting male coalition importance.
- Riskier behaviours: Chimpanzee males displayed elevated rates of “risky intimate behaviours,” such as placing fingers or hands in another’s mouth, particularly in tolerant groups, suggesting these acts function as trust signals.
Evolutionary Implications
The similarity of reassurance behaviours in both species points to a common evolutionary origin predating the human–ape split, estimated at least six million years ago. Researchers argue that touch represents an ancient communicative channel that predates language and may have been a foundational tool for maintaining group cohesion and managing competition throughout primate evolution.
Official Statements & Responses
Both scholars suggest that the observed “reassurance trains” illustrate a flexible, short-term strategy for preserving harmony before resource competition.
Verbatim Quotes
- “Before stressful events, they come together, they reassure each other, they touch each other, they hug each other,” — Prof Zanna Clay. She
- “Comparing bonobos and chimpanzees - our two closest relatives - offers fascinating insight into the evolutionary roots of social behaviour and how they, and we, manage tension, competition and cooperation,” — Dr Jake Brooker. He
Future Directions
The research team plans to investigate whether pre-feeding reassurance predicts later tolerance and conflict risk on a pair-by-pair basis. A subsequent phase will measure physiological stress markers (e.g., cortisol) in both the initiator and recipient of touch to determine whether the behaviour directly reduces stress. Funding for these extensions comes from the Templeton World Charity Foundation, with collaboration from the Max Planck Institutes, the University of Konstanz, Utrecht University, and New York University.
Why It Matters
By demonstrating that a simple, non-verbal gesture can shape cooperation in our closest relatives, the study provides a comparative framework for understanding the deep roots of human social rituals—such as pre-game huddles, handshakes, or hugs—that may serve similar tension-reducing functions. This insight bridges primatology and social psychology, suggesting that the “social toolkit” of touch has been conserved across millions of years of evolution.
