Cattell–Horn–Carroll theory

Based on a large body of research, spanning over 70 years, Carroll's Three Stratum theory was developed using the psychometric approach, the objective measurement of individual differences in abilities, and the application of factor analysis, a statistical technique which uncovers relationships between variables and the underlying structure of concepts such as 'intelligence' (Keith & Reynolds, 2010).

The psychometric approach has consistently facilitated the development of reliable and valid measurement tools and continues to dominate the field of intelligence research (Neisser, 1996).

At this meeting Horn presented the Gf-Gc theory to several prominent figures in intelligence testing, including John B. Carroll (McGrew, 2005).

Although there are many similarities between the two models, Horn consistently and unyieldingly argued against a single general ability g factor (McGrew, 2005, p. 174).

Unlike Horn, Carroll argued that evidence for a single 'general' ability was overwhelming, and insisted that g was essential to a theory of human intelligence.

[citation needed] Fluid intelligence refers to quantitative reasoning, processing ability, adaptability to new environments and novel problem solving.

Gc tasks include problem solving with familiar materials and culture-fair tests of general knowledge and vocabulary.

[citation needed] Recent research has explored the idea that training on working memory tasks can transfer to improvements in fluid intelligence.

[10] The American psychologist John B. Carroll (June 5, 1916 – July 1, 2003) made substantial contributions to psychology, psychometrics and educational linguistics.