Kevin McGrew on IQ scores, borrowing from Detterman (2016) and McGrew et al., (2023)
“General intelligence (represented by a composite IQ score or the factor-analysis derived psychometirc g factor) is a fallible summary statistical (numerical) index of the efficiency of a complex system of dynamically interacting multiple brain networks. Like the emergent statistical index of horsepower of a car engine, which does not represent a “thing” (a mechanism) in the engine, it reflects the current estimated efficiency of the processing of multiple interacting cognitive abilities and brain networks. It should not be interpreted as being the result of a single brain-based entity or mystical mental energy, as fixed, or reflecting biological/genetic destiny. The manifest expression of this statistical emergent property index is also influenced by other non-cognitive (conative) (click for relevant article) traits and temporary states of the individual and current environmental variables” (K. McGrew, 11-07-24)