Lynn and Vanhanen have a new paper out in which they summarize, in 19 tables, the research to date on National IQs. (Bottom.) It’s interesting that IQ tests and international assessments predict as they do, but it’s not at all clear what the national IQ differences represent (Lynn’s updated National IQs, here)– it’s not even clear if there are actual differences in ability. With regards to the latter point, here were the results from a recent study on measurement invariance and the 1999 TIMSS (Trends in International Mathematics and Science Study):
The authors rightfully conclude:
For cross-culture MI examinations, only weak invariance, at best, is achieved. This result indicates that intercept invariance does not hold for any of the cross-culture comparisons, hence, the mathematics test, as a whole, was consistently biased against one of the countries in the pairs. One cannot infer that there is true group difference even if the hypothesis test, such as a t-test, is significant because the detected difference might be an artifact of the measurement bias. Any research or policy exercise such as ranking performances or explaining group differences based on such mathematics proficiency scores is not meaningful because mathematics proficiency scores were not measured on the same metric unless some forms of linking or equating, which have their own variation of MI assumptions, is performed before comparison.