Intelligence is multidimensional: Theoretical review and implications of specific cognitive abilities

Human resource management researchers typically treat cognitive ability as a unidimensional construct. The current paper reviews possible rationales for this choice, including practical convenience, the parsimony of Spearman's theory of general mental ability (g), positive manifold among cognitive tests, and empirical evidence of only modest incremental validity of specific cognitive abilities for predicting job and training performance over and above g. In contrast to HR researchers' dominant practice of treating cognitive ability as unidimensional, we recommend a renewed interest in narrower, second-stratum cognitive abilities. The renewed focus on multiple dimensions of intelligence is supported by several arguments, including superior empirical fit of hierarchical and oblique multifactor models over unidimensional models of cognitive test data, the Cattell–Horn–Carroll theoretical model and Carroll's large-scale empirical support for a hierarchical model of intelligence with several second-stratum factors (i.e., specific cognitive abilities), empirical evidence of modest incremental validity (typically at or above 2%) of specific cognitive abilities predicting job performance beyond g, the notion of a compatibility principle of the cognitive ability–job performance relationship in which specific abilities should predict specific criteria but not broad criteria, application of bifactor and relative importance methodologies to predict job performance via g and specific abilities simultaneously, evidence that adverse impact in hiring can be partly curtailed by differentially weighting specific cognitive abilities, and theoretical models of reciprocal causation among specific cognitive abilities which can explain positive manifold in the absence of g. After arguing for multidimensional models of intelligence, we review a variety of second-stratum cognitive abilities that have been described under the Cattell–Horn–Carroll model, highlighting similarities and differences among specific abilities.