A new study published in Science has challenged the long-held belief that only humans are capable of forming solid and strategic cooperative relationships and sharing resources between non-family groups. Researchers from Harvard University and the German Primate Center found that bonobos, our closest living relatives, display prosocial behavior that extends beyond their own group to contribute socially to different groups.

Studying humans’ closest living relatives, chimpanzees and bonobos, helps reconstruct ancestral human traits such as cooperation and conflict. While chimpanzees often display hostility and lethal aggression, bonobos show levels of tolerance and cooperation that pave the way for prosocial cooperative behaviors.

The study reveals a remarkable level of tolerance between members of different groups that leads to strong bonds between prosocial individuals. Bonobos do not interact randomly between groups; instead, they preferentially interact with specific members of other groups who are more likely to return the favor, leading to peaceful intergroup relations.

This ability of bonobos to maintain peaceful intergroup relations while extending acts of prosociality and cooperation challenges existing theories about what promotes cooperation over conflict. The authors emphasize the similarities between the social cooperation of bonobos and that of humans, challenging the idea that culture and social norms are necessary components for cooperation between groups to emerge.

The study reinforces the idea that constant war between neighboring groups is not necessarily a human legacy or evolutionarily inevitable. Instead, it suggests that peaceful intergroup relations and cooperation are present in closely related species like bonobos, shedding light on the true nature of intergroup relations and cooperative behavior.