Spearman's hypothesis tested comparing Libyan secondary school children with various other groups of secondary school children on the items of the Standard Progressive Matrices

Spearman's hypothesis tested at the level of items states that differences between groups on the items of an IQ test are a function of the g loadings of these items, such that there are small differences between groups on items with low g loadings and large differences between groups on items with high g loadings, and it has been confirmed in a limited number of studies. In this paper, we tested Spearman's hypothesis, comparing a group of Libyan secondary school children (N = 1080) with other groups of secondary school children from Bosnia and Herzegovina, Estonia, Ukraine, Russia, South Africa, Ireland, and Chile (total N = 7476). The analyses were carried out on 9 comparisons between the Libyan children and the other children. Spearman's hypothesis was strongly confirmed with a mean weighted r with a value of .61. We conclude that Spearman's hypothesis tested at the item level appears to be a more regular phenomenon than previously thought.