— National IQ research
Average IQ in Thailand
Estimated avg IQ
91
Percentile
27th
Region
Southeast Asia
vs world avg (82)
9 points above
Published cross-national IQ research places Thailand at an estimated national average IQ of around 91. This is a population mean estimate with wide confidence intervals — not a fixed number.
Thailand's average is above the Southeast Asian mean, though below Singapore, Vietnam, and Malaysia in most cross-national studies.
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- Scores are rising in most countries (the Flynn effect) — estimates from 10+ years ago are already outdated
How do you compare?
Take a 20-minute IQ test and see your personal score — regardless of where you're from.
Countries with similar average IQ
- Average IQ in Italy — estimated 96
- Average IQ in Portugal — estimated 95
- Average IQ in Greece — estimated 94
- Average IQ in Ukraine — estimated 96
- Average IQ in Brazil — estimated 87
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.