Overview
- The peer‑reviewed study, published 22 July 2026 in Proceedings of the Royal Society B, found that groups of chimpanzees and bonobos that touched each other more before feeding were likelier to eat together peacefully.
- Researchers filmed 116 individuals across five semi‑wild groups during 60 controlled co‑feeding sessions at two African sanctuaries and analysed more than 10 hours of footage to measure pre‑feeding contact and later tolerance.
- Reassuring behaviours included embraces, pats, hand‑holding, genital contact and risky trust gestures such as placing fingers in another’s mouth, and these acts were linked to greater peaceful co‑feeding.
- The effect varied by species and alliances, showing strongest links for female–female pairs in bonobos and male–male pairs in chimpanzees, which matches known social structures of each species.
- Authors stress the result is correlational not causal and plan follow‑up work to measure stress hormones and run longitudinal pair analyses to see if touch reduces tension or simply signals preexisting tolerance; the finding also suggests touch may be an ancient tool for managing social stress with implications for human social evolution.