To understand the origins of human sociality studying the social dynamics of our closest relatives, chimpanzees and bonobos, is important. Using behavioral and hormonal data from a habituated bonobo community at the long-term LuiKotale field site in the Democratic Republic of Congo researchers from the Max Planck Institute for Evolutionary Anthropology, Harvard University and the Leibniz Institute for Farm Animal Biology have now shown that same-sex sexual behavior in female bonobos increases friendly social interactions, including cooperation.