Ability differentials between nations are unlikely to disappear

Area of Science:

• Psychology
• Sociology
• Human Intelligence Studies

Background:

• The Flynn effect, a rise in average IQ scores over time, has been proposed to resolve international intelligence disparities.
• Nisbett et al. argued that these gains would eliminate cross-national IQ inequalities by the end of the 21st century.

Purpose of the Study:

• To critically evaluate the claim that the Flynn effect will resolve international IQ inequalities.
• To examine the recent trends of the Flynn effect in developed countries.
• To differentiate between accelerated childhood development and actual increases in adult intelligence.

Main Methods:

• Analysis of existing data on IQ score trends.
• Review of cohort studies from Europe and the United States.
• Theoretical discussion on the interpretation of intelligence gains.

Main Results:

• Flynn effect gains have become rare in cohorts born after approximately 1980 in Europe and the United States.
• The evidence does not support the optimistic projection that the Flynn effect will eliminate all cross-national IQ inequalities by 2100.
• Distinguishing between accelerated childhood development and sustained higher adult intelligence is crucial for accurate interpretation.

Conclusions:

• The assumption that the Flynn effect will universally equalize intelligence is not supported by recent empirical data.
• Further research is needed to understand the complex factors influencing both childhood development and adult intelligence across nations.
• The hypothesis that some nations inherently lack the intelligence for industrialization remains a contentious issue, not resolved by current Flynn effect trends.