Scientists studying learning and memory know Walter Samuel Hunter best for his analytical application of a device for assessing short-term retention, the delayed-response task. But his contributions to psychology were much more broad, and deep, than that. He was an influential and moderating force in the behaviorist movement; his thoughts and experiments included topics that remain issues of mainstream interest, such as the nature of an animal's representation for memory, consciousness, and genetic influences on intellectual achievement; and he was a significant applied psychologist with the military.

When Hunter was born, in 1889, it had been about a century since his Scotch-Irish ancestors had come to the United States. Born in Decatur, Illinois, within a year of the births of U.S. president Dwight D. Eisenhower (1953 to 1961), French soldier Charles de Gaulle, German dictator Adolf Hitler, English motion-picture actor Charles Chaplin, and English...