IQ tests and theory trends: Google Ngram visualizations

This past week I read a very intriguing article in the New York Times about a new data visualization tool offered by Google-- the Google Books Ngram Viewer. I then ran across a legal blog post where someone had investigated trends in different law terms...and I couldn't help myself but to give it a try.

As described by Robert Ambrogi at the legal blog:

"Using data drawn from the millions of books it has digitized covering the years 1500 to 2008, it lets you see and compare the frequency of words and phrases as they were used in books over a span of years or centuries. As Google puts it: “The Ngram Viewer lets you graph and compare phrases from these datasets over time, showing how their usage has waxed and waned over the years.”

I first had to experiment with how the entered terms worked. The terms are case sensitive. I checked each phrase with a variety of permutations to maximum the "hit rate"...and then ran some phrases together to ascertain and compare trends.

Below are my results with a few comments--the data tend to speak for themselves. I found that most of what I searched for did not emerge until after 1940...so that is where each graph starts. It is also important to note that the graphs only go up thru 2008...it would be nice to see the graphs up today

Cool stuff. Double click on each graph to enlarge.

This chart suggests that the cognitive ability domains of Gv (Visual Processing), Ga (Auditory Processing), and Processing Speed (Gs) have become hotter topics than Gf (Fluid Intelligence), Gc (Crystallized Intelligence), Gsm (Short term Memory), and Glr (Long term Retrieval). Interesting.

One very clear observation. Among the non-Wechsler intelligence batteries, the Stanford Binet has dropped dramatically over time, while the "newbies" on the IQ testing block (WJ, DAS, KABC, CAS) have made been the focus of more writing since 1990. Note, "Wechsler Intelligence", when included, is the clear winner across time. I left it out so the trends for the "other" batteries would be more distinct.

As I have written about many times, contemporary Cattell-Horn-Carroll (CHC) intelligence theory has become the consensus theory of intelligence. This interesting graph supports this conclusion, especially from 1997 to 2008. Also, if one clicks on the search term in the summary table, one is taken to a page of the Google books that included the term. Click here to see example for CHC theory.

I think many of the trends noted above are due to emergence of Gf-Gc theory to CHC theory with the publication of the 1989 WJ-R. I've written about this critical theory-to-practice birth period here and here.

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