B.F. Skinner

Burrhus Frederic Skinner (1904-1990) was an American psychologist, inventor and social philosopher, and one of the central figures of twentieth-century behaviorism. Together with Ivan Pavlov and John B. Watson, he is regarded as one of the pioneers of modern behaviorism. A 2002 survey by the American Psychological Association ranked him as the most influential psychologist of the twentieth century. His work belongs to a tradition that, in opposition to depth psychology and other speculative schools, sought to explain behavior through what can be observed and tested in the laboratory.

Born in Susquehanna, Pennsylvania, he was the son of a lawyer. He left religion behind in his youth after a Christian teacher tried to calm his fear of hell, a story he often recalled. He first wanted to become a writer and studied English literature at Hamilton College. When his early literary efforts failed, a period he later called his "Dark Years", he turned to psychology, partly after reading Bertrand Russell's account of Watson's behaviorism. At Harvard, Fred S. Keller encouraged him to treat behavior as a subject for experimental science. He earned his doctorate there in 1931, taught at the University of Minnesota and Indiana University, and returned to Harvard in 1948, where he stayed until his retirement in 1974.

His central contribution is what he called radical behaviorism. For Skinner, behavior is shaped by the reinforcement histories of an organism in its environment, and there is no need to invoke inner mental states to explain it. In The Behavior of Organisms (1938) he distinguished two kinds of behavior: respondent behavior, elicited by stimuli and modified through the classical conditioning studied by Pavlov, and operant behavior, emitted without a specific trigger and strengthened or weakened by its consequences, a process Edward Thorndike had explored. Skinner brought both under a single framework. To study this he invented the operant conditioning chamber, known as the Skinner box, and the cumulative recorder.

His ideas also reached well beyond the laboratory. In the utopian novel Walden Two (1948) he imagined a community organized around operant principles, and in Beyond Freedom and Dignity he argued that human behavior could be designed through reinforcement to improve collective well-being. These proposals drew sharp criticism, especially for their rejection of personal freedom as an explanation and for their view of behavioral control. His influence endures in behavior therapy, education, applied behavior analysis and experimental psychology, although his accounts of language and mind remain widely debated.