Bonobos in the wild cooperate with other groups, just like us

Photo: Pixabay/NauticalVoyager

Bonobos have been dubbed hippies among apes as they tend to be far less violent than their chimpanzee cousins and engage in plenty of mutual grooming behaviours, some of them risqué.

In that they resemble humans quite a lot and it turns out the similarities do not end there. Researchers from Harvard University and the German Primate Center have found that bonobos cooperate beyond their own groups in a form of societal cooperation.

While chimpanzees in one group are invariably hostile to those in others, frequently dishing out lethal aggression, bonobos are far less likely to do so. The scientists have reached this conclusion after studying the apes in their natural habitat in the Kokolopori Bonobo Reserve in remote parts of the Democratic Republic of the Congo.

“Cooperation beyond familial and group boundaries is core to the functioning of human societies, yet its evolution remains unclear. To address this, we examined grooming, coalition, and food-sharing patterns in bonobos (Pan paniscus), one of our closest living relatives whose rare out-group tolerance facilitates interaction opportunities between groups,” the scientists write in a paper on their findings.

“We show that, as in humans, positive assortment supports bonobo cooperation across borders. Bonobo cooperative attitudes toward in-group members informed their cooperative relationships with out-groups, in particular, forming connections with out-group individuals who also exhibited high cooperation tendencies,” they explain.

When different groups of bonobos encounter one another, they often end up traveling, resting, and feeding together, according to the researchers, who saw no disputes that led to lethal aggression as often happens among chimpanzees.

“Tracking and observing multiple groups of bonobos in Kokolopori, we’re struck by the remarkable levels of tolerance between members of different groups,” says Liran Samuni, an expert at the German Primate Center in Göttingen. “This tolerance paves the way for pro-social cooperative behaviors such as forming alliances and sharing food across groups, a stark contrast to what we see in chimpanzees.”

It appears, however, that bonobos do not interact randomly between groups because cooperation takes place between those already familiar with one another, according to the researchers.

“They preferentially interact with specific members of other groups who are more likely to return the favor, resulting in strong ties between pro-social individuals. Such connections are also key aspects of the cooperation seen in human societies,” says Martin Surbeck, an assistant professor at Harvard’s Department of Evolutionary Biology.

“Bonobos show us that the ability to maintain peaceful between-group relationships while extending acts of pro-sociality and cooperation to out-group members is not uniquely human,” he stresses.

People cooperate across societies regardless of differences in cultures, traditions and social norms. This has led to “the exchange of ideas, the spread of innovations, and the accumulation of knowledge over space and time,” the scientists note.

“Human networks foster the exchange of resources, resulting in the trade of materials and goods that can offset shortfalls. Bonobos also share resources across groups, and they do so without any strong cultural influence,” they elucidate.

In other words, bonobos are just like us to some extent.

“The bonobos show that constant warfare between neighboring groups is not necessarily a human legacy and does not seem evolutionarily inevitable,” the experts say.