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How Chimpanzees Choose Their Friends

By Russell Tenofsky

It may not be birds of a feather, or even great minds think alike, but a recent study has shown that chimpanzees tend to choose friends with similar personality types.

Photo of a chimpanzee sitting on a tree branch alone and with folded arms.

As published in the journal Evolution and Human Behavior, Jorg Massen of the University of Vienna and Sonja Koski of the University of Zurich “investigated personality similarity of friends in 38 captive chimpanzees.” Based on past behavioral studies and observing “which chimpanzee sat in body contact with whom most,” the scientists concluded the chimpanzees chose companions based on similarities in personality.

“We found that, especially among unrelated friends, the most sociable and bold individuals preferred the company of other highly sociable and bold individuals, whereas shy and less sociable ones spent time with other similarly aloof and shy chimpanzees,” Dr. Massen said.

The scientists contend that seeking out individuals with similar emotional states and behaviors is an adaptive trait.

“We suggest that having friends similar to self in personality decreases uncertainty in interactions by promoting reliability especially in cooperative contexts, and is consequently adaptive.”

These findings, according to the scientists, are akin to the “similarity effect” in humans – the idea that “like” minded and introverted and extroverted people gravitate toward each other.

“It appears that what draws and keeps both chimpanzee and human friends together is a similarity in gregariousness and boldness, suggesting that preference for self-like friends dates back to our last common ancestor,” said Jorg Massen.

Note: The Nonhuman Rights Project does not endorse experimentation on captive animals. However, we do quote the results of these experiments when they help make the case that the animals have a level of sentience, self-awareness, and, in some cases, a theory of mind that demonstrates that we should not keep them in captivity in the first place.

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