Primatologist Shirley Strum has spent more than fifty years following the same olive baboons in Kenya, and what she found was not a hierarchy of aggressive males but a society running on friendship, memory of who helped whom, and constant negotiation

Shirley Strum's decades of fieldwork on olive baboons in Kenya reshaped how biologists think about primate societies, replacing a model built on male aggression with one built on long-term female relationships and something that looks, from the outside, like a favour economy.