British-born American psychologist, considered to be one of the world's leading personality theorists.

Cattell was educated at the University of London, receiving a B.S. in 1924 and a Ph.D. in 1929. He taught at the University of Exeter (1927–32), after which he served as director of the Leicester Child Guidance Clinic (1932–37). Cattell then taught at Clark University in Worcester, Massachusetts (1939–41). After a brief stint as a lecturer at Harvard University (1941–43), he was appointed research professor of psychology at the University of Illinois in Urbana (1945), a position he held until becoming emeritus professor in 1974.

Cattell was a prolific writer in the field of psychological measurement. Among his many books are The Meaning and Measurement of Neuroticism and Anxiety (1961), Handbook of Multivariate Experimental Psychology (1966), Prediction of Achievement and Creativity (1968), and Abilities: Their Structure, Growth, and Action (1971).

Personality and Learning Theory, 2 vol. (1979–80), is considered Cattell's most important work. In it he proposed a theory of human development that integrates the intellectual, temperamental, and dynamic aspects of personality in the context of environmental and cultural influences. He was able to synthesize in this work many of the disparate hypotheses of both personality and learning theories.