This debate started in the early 2000's after Richard Lynn and Tatu Vanhanen constructed and published IQ estimates for many countries using literature reviews, student assessment studies and other methodologies.
The European Human Behavior and Evolution Association issued a formal statement in 2020 discouraging use of Lynn's datasets and describing them as unscientific.
[3] On July 27, 2020, the European Human Behavior and Evolution Association issued a formal statement opposing the utilization of Lynn's national IQ datasets, arguing that they "fall a long way short of the expected scientific standard of rigour, in terms of both data curation and measure validity."
van der Maas conducted a new analysis of IQ in sub-Saharan Africa, which was critical of many of Lynn and Vanhanen's methods.
[13] Wicherts et al. concluded that Lynn and Vanhanen had relied on unsystematic methodology by failing to publish their criteria for including or excluding studies.
Wicherts at al. conclude that this difference is likely due to sub-Saharan Africa having limited access to modern advances in education, nutrition and health care.
[12] Rindermann (2007) states that the correlations between scores of international student assessment studies and psychometric measures of national IQ are very high.
[14] However, a 2017 systematic review notes that other researchers have dismissed Rindermann's findings on the basis that "the meaning of variables shifts when you aggregate to different levels; a conceptual, methodological point that is well-established in the field of multi-level modelling.
He argues that substantial correlations between intelligence test scores and measures of well-being exist when the analysis is limited to developed countries, where the IQ results are more likely to be accurate.
Hunt and Wittman (2008) state that although the correlation between national IQ and economic well-being is clear, any possible causality between them is more difficult to determine.
[19] Writing with Robert J. Sternberg in 2006, Hunt argued:[20] When dealing with dramatically different levels of health, educational opportunity and economic development within the country, the concept of national IQ is meaningless without carefully designed probability samples of the population.
"[21] Eppig, Fincher, and Thornhill (2010) states that the most important factor in predicting national IQ by a large margin is the prevalence of infectious disease.
In a 2001 review article, Robert J. Sternberg, Elena Grigorenko, and Donald Bundy argued that IQ comparisons between rich and poor nations can be "dangerously misleading", and that IQ comparisons between nations may be meaningfully applied "only through selected segments of the Western part of the industrialized world.
Work with the Tsimane and with children in Mali, for instance, has demonstrated that low scores on IQ tests in these groups are not replicated in other, more culturally relevant or familiar tasks.