Humans are unique in their abilities to cooperate in very large groups and help people outside their family and even complete strangers. What promoted the evolution of such sophisticated cooperative skills is highly debated. Scientists investigated cooperation dynamics in wild chimpanzees (Taï, Ivory Coast) and bonobos (LuiKotale, DCR) using a snake model. While chimpanzees cooperate to defend their territory, bonobos do not. The study reveals no differences in both species’ social intelligence but supports theories linking territoriality and in-group cooperation in humans since chimpanzees were more motivated to cooperate by informing others of a threat as compared to bonobos.