A study conducted across sanctuaries in the Democratic Republic of Congo and Zambia has revealed that bonobos and chimpanzees utilize physical touch as a tool to mitigate tension before conflict arises. Researchers observed 116 apes across five groups, focusing on how the animals interacted during high-stakes moments, such as the anticipation of food.

Using a testing method known as the "peanut swing," researchers monitored interactions as apes waited for food to be distributed. The findings indicated that individuals who engaged in friendly physical contact—such as embracing, patting, or kissing—prior to the arrival of food were more likely to feed peacefully alongside others. This behavior was particularly prevalent in groups characterized by higher levels of social tolerance.

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The study also highlighted how these interactions align with the specific social structures of each species. Among bonobos, female-female pairs were the most frequent users of reassuring touch, reflecting their society's female-led alliances. In contrast, male chimpanzees were the primary participants in such exchanges, mirroring the importance of male coalitions within their groups. In some instances, chimpanzees engaged in high-risk behaviors, such as placing body parts into each other's mouths, which researchers suggest may serve as a profound signal of trust.

The authors of the study suggest that this reliance on touch to navigate social stress is an ancient evolutionary trait. Because bonobos, chimpanzees, and humans share a common ancestor from over six million years ago, the researchers conclude that the use of touch to maintain social harmony likely predates the emergence of the human species. This behavior mirrors human social dynamics, where physical contact—from handshakes to team-based gestures in sports—is frequently used to build cooperation and reduce anxiety.

Source: The Conversation