Clark Leonard Hull

Clark Leonard Hull

(1884-1952)

• Hull’s life

• U. of Wisconsin: studied mining engineering before psychology

• 1918: Ph.D. from Wisconsin

Clark Hull

• early work

o concept formation

o effects of tobacco on behavioral efficiency

o test and measurements

o applied area: Aptitude Testing (1928)

o practical methods of statistical analysis

o invented a machine for calculating correlations

o hypnosis and suggestibility: 10 years, 32 papers, 1 book (1933)

Clark Hull

• 1929: research professor at Yale

• theory of behavior based on Pavlov’s laws of conditioning

o his final research interest

o 1927: read Pavlov

o 1930s: articles about conditioning

o 1940: Mathematico-Deductive Theory of Rote Learning

o 1943: Principles of Behavior

o 1952: A Behavior System

Clark Hull

• The spirit of mechanism

• omitted mentalistic terms, including consciousness and purpose

• used mechanistic terms

• human behavior

o mechanistic, robotic

o automatic

o reducible to the language of physics

• machines could be constructed that would display human cognitive functions

Clark Hull

• Objective methodology & quantification

• objective experimental methods

• quantitative

• laws of behavior expressed in language of mathematics

o equations

o empirical constants

o theorems and corollaries

Clark Hull

• objective definitions

• rigorous deduction

• four methods

o simple observation

o systematic controlled observation

o experimental testing of hypotheses

o the hypothetico-deductive method

o establish postulates

o deduce experimentally testable hypotheses

o submit them to experimental test

o method necessary for psychology to be a science

Clark Hull

• Drives

• motivation

o a state of bodily need

o arises from a deviation from optimal biological conditions

• drive

o an intervening variable

o a stimulus arising from a state of tissue need

o arouses or activates the behavior

Clark Hull

o its strength is empirically determined

o is nonspecific

o energizes behavior

o does not direct behavior

o direction of behavior determined by environmental stimuli

o reinforcement: reduction or satisfaction of a drive

Clark Hull

• primary drives

o arise from a state of physical need

o are vital to the organism’s survival

• secondary