European and American WAIS IV norms: Cross‐national differences in perceptual reasoning,processing speed and working memory subtest scores

International comparisons of IQ test norms show differences between nations. In the present study, nonverbal reasoning, processing speed and working memory subtest scores of the US, German, French, Finnish, and Scandinavian (combined Swedish‐Norwegian‐Danish sample) WAIS IV standardization samples were compared. The European samples had higher scores on the reasoning subtests compared to the American sample, corroborating earlier studies. The Finnish and Scandinavian samples had lower processing speed and working memory scores than the American, German, and French samples. Mechanisms that may underlie the observed national IQ profiles include: (1) test‐taking attitudes—in tests that require balancing speed and accuracy of performance Americans may prioritize fast performance while Europeans avoid mistakes; (2) differences between languages in digit articulation times; and (3) educational factors—the European advantage on reasoning subtests may be based on there being better educational systems in Europe as compared to the US.     

II. The comparability of the WISC-R and WAIS among 16-year-old EMR children

Thirty 16-year-old EMR children were administered the WAIS and WISC-R in counterbalance order to determine the comparability of the two assessment instruments. The WAIS was found to yield significantly higher Verbal, Performance, and Full Scale IQ scores. The comparisons of corresponding subtests indicate that all WAIS subtests were significantly higher than the WISC-R except Picture Completion. Correlations between corresponding WAIS and WISC-R IQ scales and subtests, however, were significant. The results suggest differences between the two instruments among children of subnormal intelligence, thus presenting the possibility that a child may be differentially classified based on the selection of the intelligence test.     

Comparability of IQ scores over time

This study investigates the comparability of IQ scores. Three cohorts (1933/36, 1997/98, 2006) of Estonian students (N = 2173) are compared using the Estonian National Intelligence Test. After 72 years the secular rise of the IQ test scores is.79 SD. The mean .16 SD increase in the last 8 years suggests a rapid increase of the Flynn Effect (FE) in Estonia. The measurement is not strictly invariant, which means that the IQ scores of different cohorts are not directly comparable. Less than perfect comparability of test scores is caused by at least two factors: time between measurements and societal/educational changes between cohorts. As was to be expected, the meaning of subtests and the meaning of the g score have changed over time.     

Comparability of WAIS and WAIS--R scores among mentally retarded adults

This study compared the performance on the WAIS and WAIS--R of 21 mentally retarded adults residing in an Intermediate Care Facility. Tests were administered in one order, the WAIS initially and the WAIS--R second, with approximately two years between testings. Significant differences were found on the WAIS and WAIS--R for Verbal, Performance and Full Scale IQs. This finding contrasts with the differences between the measures as reported in the WAIS--R manual.