David Premack

David Premack (1925 to 2015) was an American psychologist and professor of psychology at the University of Pennsylvania. He was educated at the University of Minnesota, where the departments of psychology and philosophy were closely allied, and began primate research in 1954 at the Yerkes Primate Biology Laboratory in Florida. His first publication, in 1959, set out a theory of reinforcement later known as Premack principle, which argues that a more probable response can reinforce a less probable one, so that reinforcement is relative rather than absolute. With Guy Woodruff he introduced the concept of theory of mind in a 1978 article. His chimpanzee work on sameness and difference showed that chimpanzees can form analogies, and he went on to study causal inference and the contrast between animal and human intelligence, arguing that human competence is domain general.