ad wide international influence. By the 1950s, the new behavioral movement had produced a mass of data on learning that led such American experimental psychologists as Edward C. Tolman, Clark L. Hull, and B. F. Skinner to formulate their own theories of learning and behavior based on laboratory experiments instead of introspective observations. Clark Hull, 1884-1952, out to pasture. Clark Hull grew up handicapped and contracted polio at the age of 24, yet he still became one of the great contributors to psychology. His family was not well off so his education had to be stopped at times, Clark earned extra money through teaching. Originally Clark aspired to be a great engineer, but that was before he fell in love with the field of Psychology. By the age of 29 he graduated from Michigan University. Hull was an objective behaviorist. He never considered the conscious, or any mentalistic notion. He tried to reduce every concept to physical terms. He viewed human behavior as mechanical, automatic and cyclical, which could be reduced to the terms of physics. Obviously, he thought in terms of mathematics, and felt that behavior should be expressed according to these terms. "Psychologist must not only develop a thorough understanding of mathematics, they must think in mathematics" (Schultz & Schultz, 1987, p 239). In Hull's time three specific methods were commonly used by researchers; observation, systematic controlled observation, and experimental testing of the hypothesis. Hull believed that an additional method was needed, - The Hypothetico Deductive method. This involves deriving postulates from which experimentally testable conclusions could be deduced. These conclusions would then be experimentally tested. Hull viewed the drive as a stimulus, arising from a tissue need, which in turn stimulates behavior. The strength of the drive is determined upon the length of the deprivation, or the intensity / strength of the resulting behavior. He b...
