Bonobos, like humans, cooperate with unrelated members of other groups
That behavior could help shed light on the evolution of cooperation between groups of people
![A female bonobo grooms a male from another group](jpg/111523_jb_bonobo-cooperation_featb14e.jpg)
An adult female in the Congo’s Kokolopori Bonobo Reserve grooms an adolescent male from a neighboring group of unrelated bonobos.
M. Surbeck/Kokolopori Bonobo Research Project