Dorothy L. Cheney, PhD: August 24, 1950 – November 9, 2018
Written by William A. Searcy and Ken Yasukawa
We are greatly saddened to report the death of Dorothy Cheney, who passed away on November 9, 2018 after a lengthy struggle with breast cancer. She was 68. Dorothy had a strong connection to the Animal Behavior Society, attending many annual meetings, publishing more than thirty papers in the society’s journal, Animal Behaviour, and serving a term (2011-2013) as an Editor. She was made an ABS Fellow in 1997 and in 2016 was named an ABS Distinguished Animal Behaviorist, the society’s highest award. Among many other honors, Dorothy was elected to the U.S. National Academy of Sciences in 2015.
Dorothy was born in Boston, Massachusetts on August 24, 1950. Her father was in the U.S. Foreign Service, and as a consequence Dorothy’s childhood was spent partly in Washington, D. C. and partly in various foreign postings, including the Netherlands, Nicaragua, Malaysia and India. For college, Dorothy attended Wellesley, from which she graduated in 1972 with a BA in political science. The political science degree was intended to prepare her for studying law, but before entering law school Dorothy decided to spend some time in South Africa with Robert Seyfarth, whom she had recently married. Robert was starting graduate work at Cambridge University under the direction of Robert Hinde, and was going to South Africa to study the behavior of baboons. Once in the field watching free-living primates, Dorothy was hooked, and she convinced Hinde to take her on as a PhD student despite her lack of an undergraduate degree in biology. She received her PhD from Cambridge in 1977.
Dorothy’s first scientific paper, published in 1977 in Nature and concerning inter-group encounters in baboons, characteristically was co-authored by Robert; from then on, they almost always worked and published together. The two denied that credit for particular ideas or experiments could be apportioned out to one or the other of them; instead all aspects of their work were truly performed jointly. As Robert put it to the New York Times: “Our scientific contributions are hard to separate… One of us had an idea, the other critiqued it, and back and forth it went until it finally took shape and neither of us remembered or cared who took credit for what.”
In 1976 Dorothy and Robert moved as postdocs to Peter Marler’s laboratory at the Rockefeller University Field Research Center, where with Marler they developed the idea of testing the semantic content of vervet monkey alarm calls. Earlier work by Tom Struhsaker had suggested that vervets give different alarm calls for different predators, and that listening vervets respond appropriately with behavior that makes them safer from the specific predators indicated by a call. In a long stint in the field in Kenya, Dorothy and Robert confirmed that vervets give specific alarms in response to specific predators (eagles, snakes, and leopards), and used playback to demonstrate that the monkeys make appropriate responses to the calls in the absence of the predators themselves. These results were the first good evidence that the natural signals of non-human primates could be referential, in the sense of referring to things or events external to the signaler. The results were published in 1980 in a short paper in Science and in a much fuller account in Animal Behaviour; in 2013 the latter was named one of the 12 most influential papers published in Animal Behaviour during its first 60 years.
Dorothy and Robert continued with fieldwork on vervet monkeys in Kenya until 1988, making further contributions to topics such as the ontogeny of alarm call usage, individual recognition of vocalizations, and reciprocity in grooming interactions. The vervet project culminated in the publication of their highly original and influential book, How Monkeys See the World, which won the inaugural Howells Book Award from the American Anthropological Association. During these years the couple moved first to UCLA where Dorothy was an Assistant Professor of Anthropology and then to the University of Pennsylvania where she spent the rest of her academic career, starting as an Assistant Professor in the Department of Anthropology and ending as a full Professor in the Department of Biology.
In 1992, Dorothy and Robert began a second, long-term field project, this one on baboons in the Okavango Delta of Botswana. One contribution of this project was to demonstrate the extent to which baboons were aware of the social relationships of other individuals, classifying others by both dominance rank and family membership. A second was to provide strong support for the importance of long-term associations with non-relatives, or friendships, to individual fitness. Through both the baboon and vervet work, Dorothy and Robert became leading proponents of the social intelligence hypothesis, which maintains that the complexities of social life have been an important source of selection leading to the expansion of cognitive abilities. Their work also had an important effect on methodology in animal behavior, through their use of ingenious playback designs to test hypotheses concerning animal communication and other aspects of social behavior. In 2007, they summarized the baboon work in another well received book, Baboon Metaphysics.
Dorothy had a profound effect on a host of other animal behaviorists through personal interactions as well as through her published work. She mentored many graduate students and post-docs who went on to distinguished careers in animal behavior, including, for example, Jacinta Beehner, Thore Bergman, Catherine Crockford, Anne Engh, Julia Fischer, Dawn Kitchen, Marta Manser, Noah Snyder-Mackler, and Klaus Züberbuhler. She also profoundly affected her many other colleagues in science, including ourselves. All who knew her were impressed by her combination of intellectual brilliance, great personal charm, and modesty. She is sorely missed.