The Cattell-Horn-Carroll Model of Intelligence
by Sarah Russin and David M Condon

The Cattell-Horn-Carroll (CHC) model of intelligence is perhaps best explained by breaking the theory down into parts that loosely correspond to the researchers after which it was named – Raymond Cattell, John Horn, and John Carroll. In the early 1940s, Cattell began developing his two factor, Gf-Gc, model of intelligence. “Gf” is the notation for fluid intelligence which can be broadly defined as one’s ability to use logic in a new situation and solve new problems with deductive or inductive reasoning, while “Gc” refers to crystallized intelligence which consists mostly of knowledge and abilities acquired over time.[1,2,3] The “g” notation in both Gf and Gc is a reference to earlier work by Charles Spearman based on his observations from early assessments of intelligence that there is considerable shared variance across the many different aspects of intelligence. In other words, scores on the many different types of measures of cognitive ability tend to be highly correlated. Spearman named this general factor “g” (and the moderately to highly correlated scores among measures are often described as demonstrating as “positive manifold”).

Beginning in the 1960s and continuing well into the 1990s, John Horn built upon Cattell’s work. Eventually, together, they proposed an eight factor model of intelligence which included measures of short-term memory, reading/writing ability, quantitative ability, and decision speed (to name a few). A new, revised structure of cognitive ability came from Carroll’s work during the 1990s. He proposed three strata or levels of abilities – general, broad, and narrow (see figure). When Horn and Carroll both attended a meeting regarding the Woodcock-Johnson tests of cognitive abilities, the similarities in their theories were quickly recognized.[4] A synthesis of these theories soon followed – the CHC Model – along with the development of a related assessment battery.


The most recent version of CHC theory includes 10 broad cognitive abilities and over 70 narrow abilities. Before 1998, the majority of intelligence battery tests measured only a few of the broad cognitive abilities. However, measures grounded in the CHC approach provide a way for practitioners and researchers to assess a much wider range of abilities than prior intelligence batteries. In a review of the influence of CHC theory on intelligence testing, Alfonso and colleagues[1] note that its breadth and flexibility make it likely to remain a key component of cognitive ability research, especially in the development of learning disability interventions.

[1] Alfonso, V. C., Flanagan, D. P., & Radwan, S. (2005). The impact of the Cattell-Horn-Carroll theory on test development and interpretation of cognitive and academic abilities. Contemporary intellectual assessment: Theories, tests, and, issues(2nd), 185-202.
[2] Cattell, R. B. (1957). Personality and motivation structure and measurement. Yonkers, NY: World Book. [3] Cattell, R. B. (1971). Abilities: Their structure, growth, and action. Boston: Houghton Mifflin.
[4] Willis, J. O., Dumont, R., & Kaufman, A. S. (2011). Factor-analytic models of intelligence. The Cambridge handbook of intelligence, 39-57.

This page last modified on September 29th, 2017.