Researchers have revealed that chimpanzees are not only capable of learning from one another, but also use this social information to form and maintain local traditions. A research collaboration between the Gonzaga University (Spokane, Washington, USA) and the Max Planck Institutes (Nijmegen, Leipzig) shows that the way in which chimpanzees groom each other depends on the community to which they belong. Specifically, it is the unique handclasp grooming behaviour that reveals this local difference. The study was reported in the Proceedings of the Royal Society B on August 29.