Cognitive Dispersion across the Lifespan: Woodcock-Johnson Normative Update and Theories of Intelligence

Individual differences in cognitive abilities and the identification of those differences have been of interest to the field of school psychology. As such, different theoretical perspectives and corresponding assessment instruments have been developed over the years as a way to assess. A growing interest in the field of school psychology has been to assess more than just general cognitive ability but to identify cognitive strengths and weaknesses. The purpose of this study was to examine the Woodcock-Johnson Normative-Update (WJ-NU; Woodcock, McGrew, & Mather, 2007) using the standardization sample in relation to the Cattell-Horn-Carroll (CHC) theory of intelligence. Confirmatory factor analyses (CFAs) were conducted across six age groups to include individuals as young as 4 years to those above 40 years of age. This study investigated three models of cognitive ability (i.e., General Intelligence, Two-Stratum, and Three-Stratum models) though to portray the structure of cognitive ability. Results of the CFAs revealed that, across all age groups, cognitive ability was best interpreted by the Three-Stratum model. Analyses indicated that the General Intelligence model, compared to the other three models was the least likely model to fit cognitive ability. The Two-Stratum model provided acceptable model fit values but was not able to identify all seven CHC abilities to an equal degree. Included are implications regarding future efforts of assessment and intervention targeted to lesser developed cognitive abilities. Limitations to internal and external validity are included