Louis L. Thurstone (1887–1955) American psychologist Louis Thurstone studied electrical engineering and was an assistant to Thomas Edison before he became interested in the psychology of learning. Thurstone was especially interested in the measurements of people’s attitudes and intelligence, and was an early critic of the idea of “mental age,” believing that intelligence was too diverse to be quantified in a single number or IQ score.

Archives of the History of American Psychology, The University of Akron. Color added by publisher