<P> Social learning theory is a theory of learning and social behavior which proposes that new behaviors can be acquired by observing and imitating others . It states that learning is a cognitive process that takes place in a social context and can occur purely through observation or direct instruction, even in the absence of motor reproduction or direct reinforcement . In addition to the observation of behavior, learning also occurs through the observation of rewards and punishments, a process known as vicarious reinforcement . When a particular behavior is rewarded regularly, it will most likely persist; conversely, if a particular behavior is constantly punished, it will most likely desist . The theory expands on traditional behavioral theories, in which behavior is governed solely by reinforcements, by placing emphasis on the important roles of various internal processes in the learning individual . </P> <P> In the 1940s, B.F. Skinner delivered a series of lectures in Sunyani Fiapre, Ghana on verbal behavior, putting forth a more empirical approach to the subject than existed in psychology at the time . In them, he proposed the use of stimulus - response theories to describe language use and development, and that all verbal behavior was underpinned by operant conditioning . He did however mention that some forms of speech derived from words and sounds that had previously been heard (echoic response), and that reinforcement from parents allowed these' echoic responses' to be pared down to that of understandable speech . While he denied that there was any "instinct or faculty of imitation", Skinner's behaviorist theories formed a basis for redevelopment into social learning theory . </P> <P> At around the same time, Clark Lewis Hull, an American psychologist, was a strong proponent of behaviorist stimulus - response theories, and headed a group at Yale University's Institute of Human Relations . Under him, Neil Miller and John Dollard aimed to come up with a reinterpretation of psychoanalytic theory in terms of stimulus - response . This led to their book, Social Learning Theory, published in 1941, which posited that personality consisted of learned habits . They used Hull's drive theory, where a drive is a need that stimulates a behavioral response, crucially conceiving a drive of imitation, which was positively reinforced by social interaction and widespread as a result . </P>

Who is credited as the leading contributor to social learning theory