Thurstone, Louis Leon (1887-1955), an American psychologist, played a major role in the development of psychological tests. One of his most significant achievements was the creation of a statistical technique called the centroid method of factor analysis. By applying the method to the results of intelligence tests, Thurstone found that intelligence consists of separate abilities, among them being reasoning and numerical aptitude. His findings differed from the common belief of the time that intelligence was a single factor.
Thurstone also developed tests to measure attitudes. He wrote several books, including Primary Mental Abilities (1938) and Multiple-Factor Analysis (1947).
Thurstone was born in Chicago. He received a Ph.D. degree in psychology from the University of Chicago in 1917. Thurstone taught psychology at the University of Chicago from 1924 to 1952.
