And according to a study published Thursday in the journalScience, we're not alone: bonobos team up with outsiders too, in everything from grooming to food sharing, even forming alliances against sexual aggressors.
Lead author Liran Samuni of the German Primate Center in Gottingen told AFP that studying the primates offered a «window into our past,» possibly signaling an evolutionary basis for how our own species began wider-scale collaborative endeavors.
Bonobos (Pan paniscus) are our closest living relatives, alongside chimpanzees (Pan troglodytes), and the two species are also very closely related to each other.
But while encounters between chimpanzee groups are inherently hostile and often result in lethal violence, interactions between bonobo parties hadn't been as well examined.
That's because bonobos, an endangered species, are notoriously difficult to study in their natural habitat — and they live only in remote regions of the Democratic Republic of the Congo.
With research on chimps dominating the literature, some scientists assumed hostility against outsiders was innate to human nature — something we had perhaps trained ourselves to get past by inventing new social norms, even as that trait lurked deep inside.
In the new paper, Samuni teamed up with Martin Surbeck, a professor at Harvard who founded the Kokolopori Bonobo Reserve, to carry out a long-term study over two years.
«The first thing they do… is try to run away from you,» Surbeck told AFP, explaining it took a long time for the bonobos to overcome their inherent fears of humans and behave normally.
Days began at 4:00 am and involved researchers trekking through the dark forest until they reached