Two new review articles on national IQs
And more meta-regression
Reader notice: I have decided to try paywalling everything in December since I need to buy baby food.
Heiner Rindermann sent me his new review paper:
Rindermann, H. (2025). Low cognitive ability estimates in developing countries: A statistical analysis of their credibility. Human Evolution, 40(3–4), 257–284. https://doi.org/10.14673/HE2025341159,
Developing countries tend to achieve weak results in international assessments of cognitive competence. Their performance is typically about one to two standard deviations below the average scores obtained in Western countries. The results are sometimes so low that they appear difficult to believe. For example, in the World Bank dataset, Nigeria scored 262 student assessment points (SASQ, about two and a half standard deviations below the norm of 500, equivalent to an IQ of 64). In the Altinok and Diebolt dataset, Yemen scored 273 SASQ (equivalent to an IQ of 66). These results have sparked criticism, and ethical as well as political-ideological debates, culminating in motivated retractions of scientific papers. In this paper, we cross-validate the reported values by comparing different data sources and applying statistical predictions. Across test paradigms, the results for groups of countries appear consistent. However, substantial discrepancies remain for individual countries. The same holds for comparisons across test collections: aggregated country results are similar, while single-country outcomes differ. Using education, GDP per capita, and political indicators to predict test scores yields somewhat higher values for the Global South (by about 5 IQ points), with the strongest effects observed in Latin America (rising from 78 to 86 IQ points). Where large discrepancies occur between observed and predicted test results, the potential for improvement appears substantial. Cultural and evolutionary background factors proved to be stronger predictors than political variables, whereas genetic distance to South or East Africa was less predictive.