Chimpanzees copy their peers just like humans, scientists have found.
Tests reveal that chimps not only ape each other, but surrender to peer pressure.
The research shows social conformity is common in chimp culture, as it is in human society.
Experts already knew chimpanzees lead a rich cultural life with different traditions unique to each community.
Some chimp populations, for instance, are adept at using sticks to capture tasty ants. Others have worked out how to crack open nuts with stone tools.
Until now it has not been clear how the apes pass on these behavioural traits.
British and United States scientists studied two chimpanzee groups at a primate research centre in the US.
First, a high-ranking female from each group was separately taught a different way to use a stick to retrieve food from behind a system of tubes dubbed "pan-pipes".
One female, Ericka, was taught to use the stick to lift an obstacle so the food fell towards her.
The other, Georgia, was instead trained to poke the "pan-pipes" so the food fell backwards and rolled into her hand.
Ericka and Georgia were then reunited with their respective groups, where they demonstrated their new skills to an appreciative audience.
Before long, the other chimpanzees were copying their two role models.
The problem proved too much for a third set of chimpanzees given the pan-pipes test without any tuition.