Fluid and Crystallized Intelligence
Fluid and Crystallized Intelligences
Raymond Cattell (1905-1998) defined intelligence in his book, Guide to Mental Testing, as follows:
"?abilities may be conceived as (1) a general ability entering into almost all performances, but far more into complex relation education than other performances; (2) certain group factors each covering an area such as verbal, number, spatial, musical, etc., performance; and (3) certain abilities which are absolutely specific to one performance."
Psychometrics, or the study of the nature of intelligence through statistical analysis, has been the basis of several theories of intelligence, including that of Cattell. The idea began with Charles Spearman, who hypothesized the existence of a general factor of intelligence (g), which was assumed to underly the positive correlations among the various tasks on IQ tests. Spearman based his claim on the results of his factor analysis of IQ test data. Cattell was also influenced by Thurstone, who introduced the concept of rotation to psychometrics. Rotation allowed Cattell to reach a new conclusion from factor analysis. He was stunned by the results. Could there, in fact, be two g?s?
Cattell named his general intelligences fluid (gf) and crystallized (gc). He discusses the concepts in Intelligence: Its Structure, Growth, and Action.
"It is apparent that one of these powers? has the ?fluid? quality of being directable to almost any problem. By contrast, the other is invested in particular areas of crystallized skills which can be upset individually without affecting the others." (Cattell, 1987)
In other words, fluid intelligence is a simple, innate, general ability, which stays fairly constant throughout life. It includes such abilities as problem-solving, memory, learning, and pattern recognition. As evidence for its continuity, Cattell documents that his gf abilities are rarely affected by brain injuries. gf is highly similar to Spearman?s original concept of g.
Crystallized intelligence, on the other hand, is more dynamic. It consists primarily of specific, acquired knowledge. For example, a child who has just learned how to recite the fifty states now owns a new piece of crystallized intelligence; but his or her general ability to learn and understand (gc) has not been altered. Not surprisingly, people with a high capacity of gf tend to acquire more gc knowledge at faster rates.
See also Intelligence (trait)
Bibliography
Cattell, R. (1936). Guide to Mental Testing. London: University of London Press
Cattell, R. (1987). Intelligence: It?s Structure, Growth, and Action. New York: Elsevier
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