Both Ivan Pavlov and B.F. (Burrhus Frederick) Skinner taught the world a great deal about behaviorism. Pavlov demonstrated how animals learned a behavioral response to stimuli. Skinner showed that animals could learn that their actions would bring a desired response — operant conditioning. His Skinner box was a sound- and light-proof chamber with a response lever. When the rat that was kept in the box pressed the lever, a food pellet was released. Skinner showed that an aspect of the rat's behavior could be conditioned. B.F. Skinner was born on this date in 1904.