The effects of language bias and cultural bias estimated using the method of correlated vectors on a large database of IQ comparisons between native Dutch and ethnic minority immigrants from non-Western countries

摘要

Cultural factors and language bias are often used to explain the large differences in mean intelligence test scores between ethnic groups, for instance majority Dutch compared to ethnic minorities. A competing explanation comes from Spearman's hypothesis, which states that these group differences in intelligence scores are a function of the cognitive complexity of the intelligence tasks, and that the regression of group differences on IQ subtests (d) on g loadings of subtests (g) leads to a regression line with only a modest amount of scatter. However, when testing Spearman's hypothesis there are two findings that have to be taken into consideration. First, sub tests of an IQ battery with a substantial language component partially measure the extent of proficiency of ethnic minorities in the Dutch language, therefore underestimate the level of g of the tested nonnative speakers, which negatively influences the hypothesized correlation between d and g. Second, ethnic minorities score relatively lower on subtests of spatial visualization and relatively better on subtests of short-term memory, and having these 'outliers' in an IQ battery also attenuates the outcome of tests of Spearman's hypothesis, and additionally tilts the regression line of don g. Spearman's hypothesis was tested using 40 datasets, comparing native Dutch to Turkish, Moroccan, Netherlands Antillean, and Surinamese immigrants. We expected to find a strong positive correlation between group differences on the subtests of an IQ battery on the one hand, and the vector of g loadings on the other hand. We then estimated the influence of language bias and the influence of cultural bias, expecting at most small effects.