Testing Spearman's hypothesis with advanced placement examination data

•Spearman's hypothesis was tested to determine if Advanced Placement score gaps were due to g.•White-Black and White-Hispanic comparisons supported Spearman's hypothesis.•White-Asian comparisons did not support Spearman's hypothesis.•Results were inconsistent for White-Native American comparisons.•Possible methodological advances for studying group differences in intelligence are suggested.

The nature, source, and meaning of average group score differences between demographic groups on cognitive tests has been a source of controversy for decades. One possible explanation is “Spearman's hypothesis,” which states that the magnitude of score differences across demographic groups is a direct function of how strongly the test measures g. To test this hypothesis, Jensen (1985, 1998) developed the method of correlated vectors. In this study I used the method of correlated vectors to examine the relationship between racial/ethnic group differences of Advanced Placement (AP) exam scores and the correlation between those AP exam scores and a test of general cognitive ability, the PSAT. Results are consistent with Spearman's hypothesis for White-Black and White-Hispanic comparisons, but not for White-Asian comparisons. Comparisons of White examinees and Native Americans are inconclusive. This study shows that academic achievement tests can be used to test Spearman's hypothesis. Additionally, Spearman's hypothesis is not a unique characteristic of White-Black differences in cognitive test scores, but it may not universal either.