'We have long been searching for the key to answering the question: 'What makes us human?' In this fascinating and engaging book, Boesch asks if the answer is 'Culture' … [He] synthesizes current knowledge of the psychology of wild and captive chimpanzees with current knowledge of the psychology of humans from diverse cultures. We arrive at a compelling new understanding of the diversity and influence of 'wild cultures', and only realize afterward that Boesch has taught us about following the scientific path to address such comparative questions. This path is important, in part, because there is still much that we do not know, and investigations in the wild are needed urgently … Boesch has provided my developmental comparative psychology students, lay people, and chimpanzee enthusiasts with greater insight into what makes us human, and what makes chimpanzees uniquely themselves.' Kim A. Bard, Director, Centre for Comparative and Evolutionary Psychology, University of Portsmouth