The American experimental psychologist Burrhus Frederic Skinner (1904-1990) became the chief exponent of that form of behaviorism known as operationism, or operant behaviorism.

Born in Susquehanna, Ohio, B. F. Skinner attended Hamilton College. He then went to Harvard, where he received a master's degree in 1930 and a doctorate in experimental psychology in 1931. In 1936 he began teaching at the University of Minnesota, the same year he married Yvonne Blue; they had two daughters.

In Skinner's first book, Behavior of Organisms (1938), he "clung doggedly to the term reflex, thus allowing his immediate psychological roots in classical or early behaviorism." A Guggenheim fellowship enabled him to begin writing Verbal Behavior in 1941. He continued on the fellowship through 1945, finishing most of the manuscript. In 1947 he gave a course at Columbia University and the William James Lecture at Harvard, both based on Verbal Behavior, which, however, he put off publishing for 20 years. Walden...