Specific Aptitude Theory Revisited: Is There Incremental Validity for Training Performance?

Specific Aptitude Theory Revisited: Is There Incremental Validity for Training Performance?

Kenneth G. Brown, Huy Le and Frank L. Schmidt
University of Iowa


There has been controversy over the years about whether specific mental abilities increment validity for predicting performance above and beyond the validity for general mental ability (GMA). Despite its appeal, specific aptitude theory has received only sporadic empirical support. Using more exact statistical and measurement methods and a larger data set than previous studies, this study provides further evidence that specific aptitude theory is not tenable with regard to training performance. Across 10 jobs, differential weighting of specific aptitudes and specific aptitude tests were found not to improve the prediction of training performance over the validity of GMA. Implications of this finding for training research and practice are discussed.

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Flynn contra Rushton on principal component analysis : A failed replication

While Rushton (1999) demonstrates, using PCA, that g and black-white differences were related, with Flynn Effect (FE) gains over time showing no relationship with the aforementioned variables, Flynn (2000) has challenged Rushton in arguing that Wechsler’s subtest loadings on the Raven test, an universally recognized measure of fluid g, showed positive correlations with both black-white differences and FE gains. Up to now, Flynn’s estimates of g fluid (Gf) has not been scrutinized. I will show presently that the Flynn’s g-fluid (call it, fluid reasoning) and Rushton’s g-crystallized (call it, consolidated knowledge) anomaly was solely due to a single statistical artifact, namely, g_Fluid vector unreliability. By adding additional samples, I created a new, updated Wechsler’s subtest Gf loadings. The present analysis comes to the conclusion that g_Fluid was not in fact correlated with FE gains. Furthermore, this Gf variable has been correlated with other variables as well, such as, heritability (h2), shared environment (c2), nonshared environment (e2), adoption IQ gains, inbreeding depression (ID), and mental retardation (MR). I will also discuss these findings in light of Kan’s (2011) thesis against the hereditarian hypothesis.

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