Investigating Spearman's hypothesis by means of multi-group confirmatory factor analysis

Differences between blacks and whites on cognitive ability tests have been attributed to a fundamental difference between these groups in general intelligence (or g, as it is denoted). The hypothesized difference in g gives rise to Spearman's hypothesis, which states that the differences in the means of the tests are related to the tests' factor loadings on g. Jensen has investigated this hypothesis by correlating differences in means and tests' g loadings. The aim of the present article is to investigate B-W differences using multi-group confirmatory factor analysis. The advantages of multi-group confirmatory factor analysis over Jensen's test of Spearman's hypothesis are discussed. A published data set is analyzed. Strict factorial invariance is tested and judged to be tenable. Various models are tested, which do and do not incorporate g. It is observed that it is difficult to distinguish between several hypotheses, including and excluding g, concerning group differences. The inability to distinguish between competing models using multi-group confirmatory factor analysis makes it difficult to draw clear conclusions about the exact nature of black-white differences in cognitive abilities. The implications of the results for Jensen's test of Spearman's hypothesis are discussed.