David Premack, professor emeritus of psychology at Penn, died on June 11 in Santa Barbara, California. He was 89 years old.
Dr. Premack was born in Aberdeen, South Dakota. He attended the University of Minnesota, where he earned his BA in chemistry and liberal arts (magna cum laude, 1943), his MA in experimental psychology and statistics (1951) and his PhD in experimental psychology and philosophy (1955). He served in the U.S. Army from 1943 to 1946.
Dr. Premack held faculty appointments at the University of Minnesota; the University of Missouri; the University of California, Los Angeles; the University of California, Santa Barbara and Harvard before joining Penn as a professor of psychology in 1975. He also established a primate study center in Honey Brook, Pennsylvania.
Dr. Premack’s career in psychology spanned a major revolution in the field. In his early work, he was a major contributor to the dominant American behaviorist enterprise with his “Premack principle,” which stated that any behavior A that is more common than another behavior, behavior B, can serve as a reinforcer for B. In his mid-career, he played a major role in the cognitive revolution by embracing it and by providing some of the best ideas and experiments to support it.
The behaviorists held that humans were just very complicated animals, with nothing qualitatively different between humans and animals. Dr. Premack showed that chimpanzees were more cognitively sophisticated than previously believed, by showing that they could comprehend and produce conceptual relations using a “language” of visual symbols.
In 1978, with his Penn graduate student Guy Woodruff, he introduced the idea of a “theory of mind,” an understanding that there are other minds. The two presented evidence for this theory in chimpanzees and gave birth to a major area of research in child development and other parts of modern psychology that are flourishing today. While Dr. Premack showed much greater intelligence in apes than had been previously thought, he also noted some uniquely human features, such as the syntax of language and the prevalence of intentional teaching as a fundamental activity. He is almost unique in psychology in his combination of theoretical and empirical excellence, and in being a contributor to two strongly opposed views of what psychology is about.
Dr. Premack retired from Penn in 1990 and moved to France, where he studied cognition in young children with his wife, Ann. They eventually returned to the Santa Barbara area. In 2005, he was designated a William James Fellow of the American Psychological Society.
Dr. Premack is survived by his wife, Ann, and three children.