Black–white differences on various psychometric tests: Spearmanʹs hypothesis tested on American armed services veterans

Psychometric data (19 variables) on the cognitive abilities of large samples of American white (W) and black (B) male armed services veterans were factor analyzed to test Spearmanʹs hypothesis that variation in the size of the mean W–B difference on various cognitive tests is directly related to variation in the size of the testsʹ loadings on the g factor. The hypothesis is strongly borne out by the data. Other factors independent of g showed no significant relationship to W–B differences in this battery of diverse tests.