Portrait of B.F. Skinner at his home in Cambridge, Massachusetts. Burrhus Frederic (B.F.) Skinner (March 20, 1904 - August 18, 1990) was an American psychologist, behaviorist, author, inventor, and social philosopher. He invented the operant conditioning chamber, also known as the Skinner Box. Skinner believed that human and animal behavior is conditioned by positive or negative reinforcement as opposed to free will.