Professor Estes received a B.A. in 1940 and a Ph.D. in 1943 both from the University of Minnesota in psychology. He has received honorary D.Sc. degrees from Indiana University (1976) and the University of Minnesota (1998). Estes first joined the IU faculty in 1946 and reached the rank of Research Professor in 1960. In 1962, he moved to Stanford University, then in 1968 to Rockefeller University and in 1979 to Harvard University. In 1999, he returned to IU as Distinguished Scholar in the Department of Psychology and in the Cognitive Science Program.
Estes's early research, centered in animal learning and behavior, was marked by the development, with B. F. Skinner, of a still widely used method of measuring emotional reactions (the "CER"). Turning to studies of visual information processing in the 1960's, he contributed to the visual detection method of estimating the information apprehended from brief visual displays. Later, his research has focused on mathematical and computer modeling of human memory and classification learning. He is credited with being one of the founders of modern mathematical psychology.
Estes was elected to the National Academy of Sciences in 1963 and the American Academy of Arts and Sciences in 1982. He received the Distinguished Research Contribution Award of the American Psychological Association in 1962, the Warren Medal of the Society of Experimental Psychologists in 1963, the American Psychological Foundation Gold Medal for Lifetime Achievement in Psychological Science in 1992 and the U. S. National Medal of Science in 1997.