A new study published in Evolution and Human Behavior shows that chimpanzees at the Ngamba Island Chimpanzee Sanctuary in Uganda steal less food from their friends, even when offered pineapple slices. Researchers analyzed 800 hours of video to identify friendships, then tested pairs where one chimp could pull a rope to steal fruit from another. Chimps consistently refrained from stealing from friends, with some refusing to participate entirely.
Lead author Oded Ritov, a social psychologist at UC Berkeley, said the findings suggest chimps have social expectations that may be a building block for human morality. Coauthor Laura Lewis of UC Santa Barbara noted that primate friendships — once dismissed as anthropomorphism — are now well-documented, with friends showing trust, support, and even jealousy. In captivity, friendships form broadly across sexes, unlike in the wild where male bonds dominate.
The study reveals that friendship can override selfish impulses in our closest relatives.
Source: New York Times Top Stories · Summarized by HeadlinesBriefing