Sunday, January 2, 2011

The continued evolution of the CHC theory of IQ: Increasing mentions in the professional literature

In my 2005 CHC Theory: Past, Present and Future chapter in Flanagan and Harrison's Contemporary Intellectual Assessment (click here to find a PDF copy of that chapter; click here for an on-line pre-pub version with additional information), I indicate that the Cattell-Horn-Carroll (CHC) theory tipping point occurred approximately 2000/2001. I first suggested a "synthesized Carroll and Horn-Cattell framework" in 1997, and the three names were linked in Flanagan, McGrew & Ortiz (2000). As explained in the 2005 chapter, the first formal published definition of CHC theory occurred in the WJ III technical manual (McGrew & Woodcock, 2001).

As I reported in a recent post, a Google Ngram semantic analysis indicated that CHC theory is now the consensus theory of intelligence, with the Ngram graph suggesting this point occurred between 2001-2002. I've reproduced that figure below. [Clicking on images below should result in reader seeing larger more readable version being presented]



To investigate the increasing impact of CHC theory, I recently completed two different searches. I took the search terms "CHC" and "Cattell-Horn-Carroll" and submitted them both to PsycINFO and the journal Intelligence issue archive. I simply asked to find any publications (journal articles, books, dissertations) where these two search terms occurred ANYWHERE in the source (title, text, references, etc). I then tallied the frequency of publications in two year chunks of time. The results are below. The goal was to ascertain if there were any relative changes in mention of this theory overt time.




The conclusions appear clear and consistent with the Google Ngram analyses noted above. The use of the two terms started to emerge in 2001-2002 and have steadily increased in the intelligence literature at large (PsycINFO) and in the premiere journal on human intelligence--Intelligence. Clearly the language of intelligence and intelligence test theory has been impacted by the CHC tipping point (circa 2000-2001).

In a subsequent post I will provide a link the references that serve as the bases of the above figure.


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