to the field of psychology. Some of these important people influenced by Hull were Albert Bandura, Neal Miller, John Dollard, Kenneth Spence, and Janet Taylor Spence. John Dollard taught anthropology, psychology and sociology at Yale and was interested in studying social class and specific learning experiences. Neal Miller studied under Hull at Yale, which is where he earned his Ph.D. Miller also founded the Laboratory of Physiological Psychology at Rockefeller University in New York, which is where he conducted research on animal training and this work helped to develop biofeedback. Miller and Dollard collaborated and developed a social learning theory that was successfully applied to psychotherapy and understanding. Their book, Social Learning and Imitation, listed the four fundamentals necessary for instrumental learning. These were drive, cue, response and reward and were based on Hull's drive reduction theory of learning. They used a similar construct to Hull's theory, however, they proposed that any strong stimulus could have motivating or drive properties without essentially being tied to the need of that particular organism. Their book, Personality and Psychotherapy (1950) is considered to be a very important book for it combined Hullian learning theory with psychoanalysis and helped to lay the foundation of cognitive behavioral therapy. Kenneth Spence was one of the most well-known of Hull's graduate students. He developed and extended Hull's neo-behaviorist theory into what came to be called the Hull-Spence theory of conditioning, learning, and motivation. This theory states that people learn stimulus-response associations when a stimulus and response occur together, and reinforcement motivates the person to engage in the behavior and increases the occurrence of the learned behavior. Spence contributed to the study of incentive motivation and developing mathematical formulation and equations to describe learning acquisition. Spence attributed improvement in performance to motivational factors rather than the habit factors of Hull's theory. He believed that reinforcement was not always necessary for learning to occur and that people can learn through latent learning. He also developed a discrimination learning theory. His discrimination theory suggests that there are gradients of excitatory and inhibitory potential that are generated around the values of the stimulus that are either reinforced or not. Janet Taylor Spence began her research while working as a graduate student with Kenneth Spence at the University of Iowa. Kenneth became her husband in 1960. Her research was on anxiety and was an extension of the Hull-Spence hypothesis. She studied anxiety