— National IQ research
Average IQ in Brazil
Published cross-national IQ research places Brazil at an estimated national average IQ of around 87. This is a population mean estimate with wide confidence intervals — not a fixed number.
Brazil's national average reflects large income inequality — high-income Brazilians in well-resourced schools perform much closer to OECD levels than the national average implies. Rapid improvement in education access over the past two decades is driving rising scores.
Important caveats about national IQ averages
National IQ averages are widely cited but require careful interpretation:
- Within-country variation is enormous — typically 15-20 IQ points of standard deviation within any country, far larger than differences between countries
- Education and nutrition access are the strongest predictors of national average IQ — countries with better early childhood nutrition and schooling score higher
- Urban vs. rural gaps can be 10-15 points within the same country
- Measurement bias is real — tests developed in Western contexts may not perfectly transfer to other cultures
- Scores are rising in most countries (the Flynn effect) — estimates from 10+ years ago are already outdated
Countries with similar average IQ
- Average IQ in Chile — estimated 90
- Average IQ in Colombia — estimated 89
- Average IQ in Mexico — estimated 90
- Average IQ in India — estimated 82
- Average IQ in Iran — estimated 84
What drives differences in national IQ?
Cross-national cognitive differences are strongly predicted by:
- Per-capita spending on education, particularly in early childhood
- Childhood nutrition — iodine, iron, and protein deficiency in early years have measurable cognitive effects
- Infectious disease burden — diseases that divert metabolic resources away from brain development
- Genetic diversity — surprisingly, more genetically diverse populations tend to score higher, not lower
- GDP per capita — as a proxy for all of the above
These factors suggest that national IQ averages are highly malleable — nutrition and education interventions reliably raise them over 1-2 generations.