I study the social behavior, vocal communication, and cognition of nonhuman primates in their natural habitat. My goal is to understand the evolution of social complexity, mind, and behavior in monkeys, apes, and humans. This work has been conducted jointly with Dorothy Cheney, who died in 2018. I was born in 1948 and graduated in 1970 from Harvard College, where my major subject was Biological Anthropology. I received a PhD from Cambridge University in 1977, then spent four years as a post-doctoral fellow at Rockefeller University. After three years at UCLA, I moved to the University of Pennsylvania, where I have been a member of the Psychology Department since 1985. I have received a Guggenheim Fellowship, been elected to the American Academy of Arts and Sciences, received an honorary doctorate from the University of Neuchâtel, Switzerland, and served as President of the Animal Behavior Society.

Research Interests

My research begins with long-term field observation of monkeys under natural conditions. Together with Dorothy Cheney, I studied vervet monkeys in Amboseli National Park, Kenya (1977-88, summarized in the book "How Monkeys See the World", 1990) and baboons in the Okavango Delta of Botswana (1992-2008, summarized in Baboon Metaphysics, 2007). I used field playback experiments to explore monkeys? vocal communication and its relation to cognition, with a particular focus on the monkeys? understanding of call meaning and their knowledge of each other?s social relationships. Our research has also considered how social relationships and social cognition contribute to fitness. More recent papers explore what the study of nonhuman primate communication and cognition might tell us about the early precursors of human language.

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Primary Section

Section 51: Anthropology

Secondary Section

Section 52: Psychological and Cognitive Sciences