The historical development of the CHC model of intelligence has been documented by McGrew (2005) and Schneider and McGrew (2012) and summarized by Kaufman and colleagues (Kaufman, 2009; Kaufman, Raiford & Coalson, 2016). An unexplained crucial, yet missing piece of the CHC story, is the origin of the original CHC broad and narrow ability definitions. The CHC ability definition birth certificate, until now, has not been located. To fend off possible CHC “birther” controversies, I will now set the record straight regarding the heritage of the past and current CHC definitions.
Given the involvement of both John Horn and Jack Carroll in revisions of the WJ-R and WJ III, which was the impetus for the combined CHC theory, it is not surprising that the relations between the “official” CHC ability definitions and the WJ tests were “reciprocal in nature, with changes in one driving changes in the other” (Kaufman et al., 2016, p. 253). Furthermore, “the WJ IV represents the first revision in which none of the original CHC theorists was alive at the time of publication, producing and imbalance in this reciprocal relationship, with the WJ IV manuals now serving as the official source for the latest CHC theory and model of cognitive abilities (J. Schneider, personal communication, March 15, 2015)” (Kaufman et al., 2016; p. 253). Kaufman et al. noted that with the development of subsequent non-WJ CHC assessment and interpretation frameworks (e.g., Flanagan and colleagues cross-battery assessment; Miller’s integrated school neuropsychology/CHC assessment model), confusion has crept into what represents the authoritative “official” and “unofficial” definitions and sources.
In Schneider & McGrew (2012), the incestuous nature of the evolution of the CHC definitions continued by building primarily on the McGrew (2005) definitions, which in turn were reflected in the 2001 WJ III manuals, which in turn drew from McGrew (1997). It is time to divorce the official CHC definitions from the WJ series and authors (particularly myself, Kevin McGrew).
However, the CHC birth certificate question is still present. Did the CHC definitions magically appear? After the Cattell-Horn and Carroll models were first married by McGrew (1997), were the definitions the result of some form of immaculate conception? Did McGrew (1997) develop them unilaterally? The original CHC definitions were presented in McGrew’s (1997) chapter where the individual tests from all major intelligence batteries where first classified as per the first integration of the Cattell-Horn and Carroll models of cognitive abilities (then called a “proposed synthesized Carrell and Horn-Cattell Gf-Gc framework”). In order to complete this analysis, I needed standard CHC broad and narrow definitions—but none existed.
I developed the original broad and narrow definitions by abstracting definitions from Carroll’s (1993) book. After drafting the first draft of the definitions I sent them to Carroll. He graciously took time to comment and edit the first draft. I subsequently revised the definitions and sent them back. Carrol and I engaged in a number of iterations until he was comfortable with the working definitions. As a result, the original definitions published in 1997 had the informal stamp of approval of Carroll, but not of Horn. The official CHC definition birth certificate should list Carroll and McGrew as the parents. Since then the CHC definitions have been primarily parented by McGrew (McGrew & Woodcock, 2001; McGrew, 2005; Schneider and McGrew, 2012; McGrew et al., 2014), and more recently, uncle Joel Schneider (Schneider & McGrew, 2012). The other WJ III and WJ IV authors (Mather, Schrank, and Woodcock) have served as aunts and uncles at various points in the evolution of the definitions, resulting in the current “official” definitions in the WJ IV technical manual (McGrew et al., 2014).
No doubt the definitions that will appear in the Schneider and McGrew (2012) chapter that is currently under revision, will likely be considered the new “official” CHC definitions as they have a clear Carroll/McGrew and WJ III /WJ IV genetic lineage (McGrew, 1997—>McGrew & Woodcock, 2001—>McGrew, 2005—>Schneider & McGrew, 2012—>McGrew et al., 2014—>Schneider & McGrew, in press). We (Schneider and McGrew) are reasonably comfortable with this fact. However, we believe it is time the CHC definitions move out of the WJ/CHC house and establish a separate residence, identity, and process for future growth. We will provides ideas on how this can be facilitated in our revised CHC chapter.
