Louis Leon Thurstone (29 May 1887–29 September 1955) was a psychometrician most notable for his contributions to factor analysis with regard to psychological tests. He is responsible for the standardized mean and standard deviation of IQ scores used today, as opposed to the mental age system originally used by Binet. He is also known for the development of the Thurstone scale.

Thurstone's work in factor analysis led him to formulate a model of intelligence center around "Primary Mental Abilities" (PMAs), which were independent group factors of intelligence that different individuals possessed in varying degrees. He opposed the notion of a singular general intelligence that factored into the scores of all psychometric tests. This idea was unpopular at the time due to its obvious conflicts with Spearman's "mental energy" model, and is today still largely discredited. Nonetheless, Thurstone's contributions to methods of factor analysis have proved invaluable in establishing and verifying later psychometric factor structures.

Thurstone was also an environmentalist, and suggested an early system for generating hydroelectric power from rivers and waterfalls.

External links

• http://www.indiana.edu/~intell/lthurstone.shtml
• http://www.psych.usyd.edu.au/difference5/scholars/thurstone.html