Researchers found that chimpanzees associate more with partners of the same sex while bonobos of either sex associate preferentially with females

Researchers of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, compared data collected from several wild communities of our closest living relatives, chimpanzees and bonobos, which show that chimpanzees associate more with partners of the same sex while bonobos of either sex associate preferentially with females. This result can be explained by different needs for cooperation. While male chimpanzees cooperate with each other during strong between-group competition, comparable to human warfare, which is absent in bonobos, bonobo males mainly rely on the help of females, especially their mothers, in conflicts with other males within their community. Females of both species, however, cooperate with other females in raising offspring.