Much has been written, both in the theoretical and applied intelligence theory/assessment literature, about
- The definition of g (general intelligence),
- Whether g exists,
- The importance of g in the prediction of a wide variety of outcomes, and
- If g exists, the importance of specific broad and narrow stratum abilities above and beyond g in the prediction of outcomes
By way of background, I have previously summarized the primary issues in “Betwixt, Behind, and Beyond g.” (Editorial note - please read this prior information before going further in this post.) In those prior writings I presented SEM analyses (of the WJ III norm data) that supported the hypothesis that working memory (actually, cognitive efficiency as defined by Gs and working memory) has a strong causal relationship to g (i.e., if you believe g is a workable and sound construct.) I also summarized research suggesting that a number of broad and narrow CHC abilities are significant above and beyond the influence of g.
So....what is this topic of this current post? Simple. To combine the working memory--> g information processing causal hypothesized model with the more traditional psychometric g+specific abilities research model.
Using the same norm samples as described in Betwixt, Behind, and Beyond g, I ran SEM causal models that defined g via the broad CHC latent abilities of Gv, Ga, Glr, Gf, and Gc. Additionally, adhering to a general information processing causal CHC model (click here to see prior relevant post), Gs and memory span (MS) are specified to be casually related to working memory, and working memory is in turn causally related to g.
The new twist is the specification of a causal path from g (as defined above) to achievement variables (letter-word identification; word attack) plus the inclusion of any significant paths from the cognitive efficiency variables (Gs and working memory) and/or the CHC abilities (that define the measurement model for g) to the dependent achievement latent variables.
All plausible models are presented and can be viewed by clicking here (Editorial note – for each age group presented, the models reported are all equally plausible. The model fit statistics did not identify any of the models in the two age groups as being better fits than the others).
Enjoy. I’d like to encourage the readers of this blog to offer interpretations and hypothesis for the various models. My only comment is that if you believe in g, the hypothesis that g is strongly related to working memory is supported (actually, to the broader notion of cognitive efficiency). Furthermore, some specific CHC abilities are again found to provide potentially important insights above and beyond the effect of g within a CHC-based information processing model.
For all who immediately shout “but what about parsimony?....what about Occam’s Razor?”….I defer to Stankov, Boyle & Cattell, R. (1995; Models and paradigms in personality and intelligence research. In Saklofske, D. & Zeidner, M. (Eds.) International Handbook of Personality and Intelligence. New York: Plenum Press), who state, within the context of research on human intelligence, that:
- “While we acknowledge the principle of parsimony and endorse it whenever applicable, the evidence points to relative complexity rather than simplicity. Insistence on parsimony at all costs can lead to bad science. “