National IQs: measurement and defense
OpenPsych , Nov. 17, 2025, ISSN: 2597-324X
Using various sources of performance on cognitive tests, we constructed a set of national IQs for 197 nations that did not rely on geographic imputations. East Asian countries scored at an average of 100, Europeans at 95, Arabs at 85, Latin Americans at 80, South Asians at 75, and Sub-Saharan Africans at 70. The observation of a low IQ of Sub-Saharan Africa and a relatively high IQ of African Americans (~85) is incompatible with a view that national differences in intelligence are completely environmental or genetic. Combining the various datasets reduced the estimated standard error of national IQs from 5.41 to 2.58, and a strong correlation between IQ and GDP per capita was observed (r = .82). Based on the prior that Flynn Effect gains do not satisfy measurement invariance, IQ scores should exhibit some non negligible bias between countries. Empirical assessments of measurement invariance across nations find that measurement invariance violations are uncommon, and are more prevalent in verbal than nonverbal tests. In most countries, national IQs show high levels of validity and we encourage their use.
