William Kaye Estes
William Kaye Estes, Daniel and Amy Starch Professor of Psychology, Emeritus, earned recognition early on as a member of a rare category containing those who exhibited both sterling personal leadership and outstanding intellectual contributions. His creative scholarship centered on learning theory, to which Harvard University’s own B. F. Skinner contributed in a major way. Many psychologists believed that the hard facts of learning theory needed a formal structure that could give rise to precise predictions. Bill Estes filled this need in 1950 in a classic paper, “Towards a Statistical Theory of Learning,” which described how organisms sampled the elements of a conditioning stimulus over successive trials so that, in time, the stimulus reliably evoked a conditioned response. Fred Skinner was not pleased that one of his best graduate students had abandoned the strict orthodoxy of behaviorism and theorized about mental events. Bill’s argument was so elegant it became one of...