Clark L. Hull: biography, theory and contributions

Clark L. Hull was a renowned American psychologist who lived between 1884 and 1952 and he was president of the American Psychological Association between 1935 and 1936. This author has gone down in history mainly for his theory of impulse reduction, but this was not his only contribution to psychology and other related sciences.

In this article we will review the biography of Clark L. Hull and his theory of impulse reduction. We will also analyze the influence of this deeply relevant theorist in the development of behaviorism, and therefore of scientific psychology.

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Clark Leonard Hull biography

Clark Leonard Hull was born in Akron, a town in the state of New York, in 1884. As he relates in his autobiography, his father was an aggressive and poorly cultivated man who had a farm. Hull and his younger brother worked on it as a child, often skipping school to help run the family business.

At the age of 17, Hull began working as a teacher in a rural school.

, but shortly after he decided that he wanted to study more, so he entered a high school and later at the University of Alma, Michigan. Shortly before graduating, he nearly died of typhoid fever.

He subsequently moved to Minnesota to apprentice a mining engineer, since he had specialized in mathematics, physics, and chemistry. However, he contracted polio; Because of this disease, he lost the ability to move in one leg. During the recovery period Hull began to read books on psychology.

After the illness he returned to work as a teacher and married Bertha Iutzi. His wife and he began attending the University of Michigan, where Hull graduated from psychology in 1913.. After working for a few years as a professor at the University of Wisconsin he obtained a position at Yale University, where he worked until his death in 1952.

Main contributions to behaviorism

Hull considered psychology to be a full-blown natural science, as are physics, chemistry or biology. As such, his laws could be formulated through numerical equations, and there would be secondary laws to explain complex behaviors and even the individuals themselves.

Thus, this author sought to determine the scientific laws that explain behavior, and in particular two complex and central aspects of human behavior: learning and motivation. Other theorists, such as Neal E. Miller and John Dollard, worked in the same direction as Hull to find the ground rules that would allow behavior to be predicted.

On the other hand, Hull was the first author to study the phenomena of suggestion and hypnosis using quantitative experimental methodology. In 1933 he published the book "Hypnosis and Suggestibility", for which he researched for about 10 years. He considered these methods to be fundamental to a deep understanding of psychology.

Hull proposed in his book "Principles of Behavior" (1943) the theory of impulse, "drive" in the original English. This work had a fundamental influence on the psychology, sociology and anthropology of the 1940s and 1950, and remains one of the classical theories of reference in the history of behaviorism and psychology in general.

Until Hull's arrival, no psychologist had translated the concepts of learning (particularly reinforcement and motivation) using mathematics. This contributed to the quantification of psychology, and consequently to its approach to other natural sciences.

The Theory of Impulse Reduction

Hull stated that learning is a way of adaptation to the challenges of the environment that favors the survival of living beings. She defines it as an active process of formation of habits that allow us to reduce impulses, such as hunger, fun, relaxation or sexuality. These can be basic or acquired by conditioning.

According to Hull, when we are in a "state of need" increases the drive, or motivation, to perform a behavior that we know from experience satisfies it. For the behavior to be executed, it is necessary that the habit has a certain strength and that the reinforcement that will be obtained by the behavior motivates the subject.

The formula that Hull created to explain motivation is as follows: Behavioral potential = Strength of habit (number of reinforcements obtained so far) x Impulse (deprivation time of need) x Incentive value of the reinforcement.

However, Hull's theory was defeated by the propositional behaviorism of Edward C. Tolman, which was more successful due to the introduction of cognitive variables (expectations) and demonstrated that there can be learning without the need for reinforcement. This fact called into question the basis of Hull's views.

Bibliographic references:

• Hull, C. L. (1943). Principles of Behavior. New York: Appleton-Century-Crofts.
• Hull, C. L. (1952). Clark L. Hull. A History of Psychology in Autobiography. Worcester, Massachusetts: Clark University Press.