The 
Cattell-Horn-Carroll (CHC) Theory of Cognitive Abilities:
Past, Present and Future
Kevin S. McGrew
University of Minnesota
One of the most successful undertakings attributed to modern 
psychology is the 
measurement of mental abilities. Though rarely appreciated outside academe, the 
breakthrough in objectively gauging the nature and range of mental abilities is a 
pivotal development in the behavioral sciences. While this accomplishment has far-
 reaching implications for many areas of society, the full meaning of the test data 
has lacked a comprehensive theory that accounts for several major developments 
over the years. The track of data left by researchers remains diffuse without a 
clear signpost in the broad landscape of mental abilities........Lamb, 
1994
Since the beginning of our existence, humans have searched 
for order in their world. Today 
classification is an activity that is essential to all scientific work (Dunn & Everitt, 
1982).  The 
reliable and valid classification of entities, and research regarding these entitites and newly 
proposed entities, requires a guide or taxonomy (Bayley, 1984; Prentky, 1994). Although 
Lambs (1994) lament about the lack of a clear signpost in the broad landscape of mental abilities 
had been true for decades, the crystallization of an empirically-based psychometric taxonomy of 
human cognitive abilities finally occurred in the late 1980s to early 1990s.
In 
1997, it was predicted that progress in intelligence testing was being, and would continue to be 
energized, as a result of the articulation of this new consensus taxonomy of human cognitive 
abilities.  The detailed description and articulation of the psychometric table of human 
cognitive 
elements in John Jack Carrolls (1993) Human cognitive abilities: A survey 
of factor-
analytic studies, which concluded that the Cattell-Horn Gf-Gc theory was the most empirically 
grounded available psychometric theory of intelligence, resulted in McGrew (1997) 
recommending that all scholars, test developers, and users of intelligence tests need to become 
familiar with Carrolls treatise on the factors of human abilities (p. 151).   
It was further 
suggested that practitioners heed Carrolls suggestion to use his map of known 
cognitive 
abilities to guide their selection and interpretation of tests in intelligence batteries (p. 151).   
It 
was the purpose of the chapter to contribute, albeit in a small way, to the building of a bridge 
between the theoretical and empirical research on the factors of intelligence and the development 
and interpretation of psychoeducational assessment batteries (p. 151).
     This 
current document continues to focus on the construction of the theory-to-practice bridge, 
a bridge grounded in the Cattell- Horn-Carroll (CHC) theory of cognitive abilities.  The 
primary 
goals of this document are to: (1) describe the evolution of contemporary CHC theory, (2) 
describe the broad and narrow CHC abilities, including, where appropriate, the integration of 
factor analytic research (since 1993) that suggests possible refinements to the taxonomy, and (3) 
review structural evidence that supports the broad strokes of CHC theory.