B. F. Skinner

Burrhus Frederic Skinner was born on 20 March 1904 in Susquehanna, Pennsylvania. He read English literature at Hamilton College hoping to write fiction, but after his Dark Years his encounter with Pavlov and John B. Watson redirected him into psychology. He entered Harvard at twenty-four, took his PhD in 1931, and from 1948 held the Edgar Pierce Chair of Psychology there for the rest of his career.

His core theory was operant conditioning. While Pavlovian respondent conditioning explained reflexes elicited by stimuli, Skinner showed that voluntary behavior is shaped by its consequences. He distinguished positive and negative reinforcement and punishment, and with Charles Ferster mapped the schedules of reinforcement. Their 1957 Schedules of Reinforcement showed that variable-ratio schedules produce the most persistent responding, the property that now underwrites slot machines, gacha games and the infinite scroll.

He was a prolific inventor: the Skinner box, the cumulative recorder, the teaching machine, and the wartime Project Pigeon. His 1945 air crib, a climate-controlled bed for his second daughter, was widely misread; a Ladies' Home Journal headline plus confusion with the Skinner box created the urban legend that he had used her as an experimental animal, which the family denied all their lives.

Walden Two (1948) designed a community around deliberate contingencies; Beyond Freedom and Dignity (1971) attacked autonomous free will and argued for a technology of behavior built on positive reinforcement. Noam Chomsky's 1959 review of Verbal Behavior argued that conditioning cannot account for linguistic creativity and helped launch the cognitive revolution; Skinner never formally replied. Applied behavior analysis still remains a primary intervention in developmental disabilities and classrooms. He died of leukemia on 18 August 1990, days after a final lecture.