For this study, European WAIS III performance subtest norms were compared to the original US norms. When European WAIS III raw scores were scored using US norms, the resulting perceptual organization index (POI) means were significantly higher than the processing speed index (PSI) means. The POI/PSI difference is roughly 5-10 points for the German…

Data from the national standardization of the French version of the WISC-III were analyzed to determine when during childhood the IQ-related process of differentiation appears and how the strength of the relationships among subtests evolves with age in low- and high-IQ groups. Indeed, some recent studies suggest that age might moderate the effect…

This paper focuses on Spearman's law of diminishing returns which states that correlations between IQ tests decrease as the intellectual efficiency increases. In the present study, data from the national standardization sample of a French intelligence scale for children aged 4 to 9 years (Echelles Differentielles d'Efficiences Intellectuelles,…