Behaviorism, also known as behavioral psychology, proposes that the basis and motivation of all human behavior is a result of external factors such as (operant and classical) conditioning, and not a result of intrinsic motivation, personality, free will, emotion, or any internal mental influences. Unlike other learning theories, behaviorism focuses on purely observable and measurable behavior.
The earliest foundations of behaviorism began with Russian scientist Ivan Pavlov, famous for his experiments regarding the digestive reactions of dogs (salivation) when paired with a stimulus (a ringing bell). His experiments led to the discovery of classical conditioning. Classical conditioning is a learning method that occurs through the pairings and associations of environmental stimuli with naturally occurring stimuli.
American psychologist John B. Watson later became one of the strongest proponents of behaviorism. B.F. Skinner continued to build upon the behaviorist theory with his concept known as operant conditioning. Operant conditioning is a means of learning that occurs through rewards and punishments.