Cross-cultural differences in cognitive performance and Spearman's hypothesis: g or c?

Common tests of Spearman's hypothesis, according to which performance differences between cultural groups on cognitive tests increase with their g loadings, confound cognitive complexity and verbal-cultural aspects. The present study attempts to disentangle these components. Two intelligence batteries and a computer-assisted elementary cognitive test battery were administered to 474 second-generation migrant and 747 majority-group pupils in the Netherlands, with ages ranging from 6 to 12 years. Theoretical complexity measures were derived from Carroll [Human cognitive abilities. A survey of factor-analytic studies. Cambridge: Cambridge Univ. Press] and Fischer [Psychol. Rev. 87 (1980) 477]. Cultural loadings of all subtests were rated by 25 third-year psychology students. Verbal loading was operationalized as the number of words in a subtest. A factor analysis of the subtest loadings on the first principal component, the theoretical complexity measures, and the ratings of cultural loading revealed two virtually unrelated factors, representing cognitive (g) and cultural complexity (c). The findings suggest that performance differences between majority-group members and migrant pupils are better predicted by c than by g.