From McGrew et al. (2023) article (click here for prior post and access to the article in Journal of Intelligence.)” Click here for a series of slides regarding the theoretical and psychometric conflation of g.
The Problem of Conflating Theoretical and Psychometric g
“Contributing to the conflicting g-centric and mixed-g positions (regarding the interpretive value of broad CHC scores) is the largely unrecognized common practice of conflating theoretical and psychometric g. Psychometric g is the statistical extraction of a latent factor (via factor analysis) that accounts for the largest single source of common variance in a collection of cognitive abilities tests. It is an emergent property statistical index. Theoretical g refers to the underlying biological brain-based mechanism(s) that produce psychometric g. The global composite score from IQ test batteries is considered the best manifest proxy for psychometric g. The conflation of psychometric and theoretical g in IQ battery structural research ignores a simple fact—“general intelligence is not the primary fact of mainstream intelligence research; the primary fact is the positive manifold….general intelligence is but one interpretation of that primary fact” (Protzko and Colom 2021a, p. 2; italic emphasis added). As described later, contemporary intelligence and cognitive psychology research has provided reasonable and respected theories (e.g., dynamic mutualism; process overlap theory; wired cognition; attentional control), robust methods (psychometric network analysis), and supporting research (Burgoyne et al. 2022; Conway and Kovacs 2015; Kan et al. 2019; Kievit et al. 2016; Kovacs and Conway 2016, 2019; van der Maas et al. 2006, 2014, 2019) that accounts for the positive manifold of IQ test correlations in the absence of an underlying latent causal theoretical or psychometric gconstruct.” (p.3; bold font emphasis added).
