Bonobo social structure as a window into our evolutionary past

What is it about?

Bonobos are considered xenophilic and in the wild they regularly encounter bonobos from other social units. During these encounters individuals behave similarly with both members of their own social units and with outsiders. They are both aggressive and affectionate, and can even form coalitions with outsiders to attack members of their own social unit. Because bonobos behave similarly with members of their own and other social units, it is challenging to define the social borders of bonobo groups. Are bonobo units indeed represent clear and distinct social groups? or are they instead better represented as neighborhoods of a single large group (as seen in Ngogo chimpanzees) This question is important because if we wish to use the bonobo as a model to study the evolution of human peacemaking and group tolerance, we must first confirm the presence of in-group/out-group identity between regularly interacting bonobo social units. Comparing the social system of the Kokolopori bonobos and the unusually large Ngogo chimpanzee group which is known to form within-group neighborhoods, we show a robust population structure in bonobos. The bonobo population structure encompasses distinct and stable groups who coordinate movements in space and time despite hanging out with outsiders. Finding that bonobos maintain in-group/out-group distinction despite a strong tendency for out-group tolerance (and even cooperation) strengthens the notion that bonobos serve as a valuable model to explore the evolution of between-group peacemaking and cooperation

Featured Image

Photo by Sean Foster on Unsplash

Photo by Sean Foster on Unsplash