Cooperative Activities in Young Children and Chimpanzees


  • Many thanks to the children and their parents for their cooperation. We thank Elena Rossi and Kristin Liebal for help with testing the children and Susanne Mauritz, Hanna Petschauer, and the keepers at the Leipzig Zoo for help with testing the chimpanzees. Thanks also to Anja Gampe and Petra Jahn for assistance in coding and to Daniel Stahl for statistical advice. We are grateful to three anonymous reviewers for their comments. These studies were conducted at the Max Planck Institute for Evolutionary Anthropology and the Wolfgang Köhler Primate Research Center in Leipzig, Germany.

concerning this article should be addressed to Felix Warneken, Department of Developmental and Comparative Psychology, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, D-04103 Leipzig, Germany. Electronic mail may be sent to


Human children 18–24 months of age and 3 young chimpanzees interacted in 4 cooperative activities with a human adult partner. The human children successfully participated in cooperative problem-solving activities and social games, whereas the chimpanzees were uninterested in the social games. As an experimental manipulation, in each task the adult partner stopped participating at a specific point during the activity. All children produced at least one communicative attempt to reengage him, perhaps suggesting that they were trying to reinstate a shared goal. No chimpanzee ever made any communicative attempt to reengage the partner. These results are interpreted as evidence for a uniquely human form of cooperative activity involving shared intentionality that emerges in the second year of life.