What Is the Average IQ in the World?

Where the cross-national numbers come from

Most published "world IQ" figures trace back to one research lineage. Psychologist Richard Lynn (1930-2023) and political scientist Tatu Vanhanen (1929-2015) compiled national IQ estimates in IQ and the Wealth of Nations (2002), expanded them in IQ and Global Inequality (2006), and updated the compilation in The Intelligence of Nations (2019, with David Becker). Their dataset is where almost every "average IQ by country" chart on the internet ultimately comes from.

It is important to be honest about how those numbers were built. Lynn and Vanhanen located usable test data for roughly half the world's countries; for many others, they estimated a national IQ from the measured values of neighboring countries. That estimation step alone should make any single decimal-place figure feel shaky.

This work is genuinely contested. In 2020 the European Human Behavior and Evolution Association issued a formal statement opposing use of the Lynn national-IQ dataset, citing methodological concerns. Independent reviews have documented that many included samples were small, drawn from a single school or region, or made up only of children — problems that are worse for some parts of the world than others. The takeaway is not a ranking to memorize but a caution: treat any global IQ figure as a fuzzy estimate with a wide margin of error, not a precise measurement.

The Flynn effect: the "average" keeps moving

Any world-average figure is also a moving target, because raw scores have risen over time. This is the Flynn effect, named after researcher James Flynn: across the twentieth century, average performance on IQ tests climbed in dozens of countries. Flynn's own early analysis of US data found gains of roughly three points per decade, and a meta-analysis of 285 studies put the average rate near 2.3 standard-score points per decade; a more recent analysis of over 1,000 samples estimated about 2.2 points per decade.

Two practical consequences follow. First, this is exactly why tests get re-normed: if scores drift upward, the publisher resets the norm so the mean stays at 100, which keeps today's 100 comparable to yesterday's. Second, a national study run in, say, 1985 will read low against a norm that has since moved on — inflating the apparent gap when it is dropped into a modern world-average calculation. Notably, in several wealthy countries the Flynn effect has slowed or even reversed in recent decades, so "scores always rise" is no longer a safe assumption either.

How much should you trust a "world average"?

Enough to hold the big picture; not enough to argue over decimals. A few honest caveats worth keeping in mind:

1. Samples are uneven. Data quality is not spread evenly across regions, so the pooled figure is systematically noisier for under-studied areas.
2. Environment moves scores. Nutrition, schooling, health, and test familiarity all affect measured IQ, and these differ enormously by country and era — the numbers reflect circumstances, not fixed traits.
3. The yardstick is Western-anchored. Anchoring the scale to a wealthy-country reference of 100 builds a below-100 world average into the method before any data is collected.
4. It is a snapshot, not a scoreboard. Because of re-norming and the Flynn effect, the "world average" you read in 2026 is not directly comparable to one published in 2006.

The useful conclusion is simpler than the debates around it: the number that describes you is your score against a current, well-normed test — where 100 is average by construction. The "world average" is a rough research estimate, interesting as context, but far too imprecise to rank people or places.

FAQ

Q: What is the average IQ in the world?

A: On the standard scale, every test is normed so its own population averages 100, while cross-country compilations estimate the global mean at roughly 82 to 90. The two figures differ because the global estimate pools uneven national studies against a Western reference, not because 100 is "wrong."

Q: Why is the world average below 100 if 100 is supposed to be average?

A: Because "100" and "world average" measure different things. 100 is the mean of a specific test's norming sample. The world figure averages many older, smaller, and unrepresentative national studies onto a Western-anchored scale, which mechanically produces a below-100 result.

Q: Are national and world IQ rankings reliable?

A: Treat them as rough estimates, not precise facts. The main dataset (Lynn, Vanhanen, and Becker) is widely used but contested — a scientific association formally objected to it in 2020 over sampling and methodology. Environmental factors and thin data make single-number comparisons unreliable.

Q: Does the world average IQ change over time?

A: Yes. Raw scores rose about 2 to 3 points per decade for much of the twentieth century (the Flynn effect), though the trend has slowed or reversed lately in some countries. Tests are periodically re-normed back to 100, which is why a fixed "world average" is really a moving snapshot.

References

• Wechsler, D. Wechsler Adult Intelligence Scale (WAIS) — norming to mean 100, SD 15. Encyclopedia.com overview
• Trahan, L. et al. (2014). The Flynn Effect: A Meta-analysis. Psychological Bulletin. PMC full text
• Sear, R. et al. (2022). "National IQ" datasets do not provide accurate, unbiased or comparable measures of cognitive ability worldwide. Preprint
• Lynn, R. & Vanhanen, T. IQ and the Wealth of Nations (2002); overview and criticism. Wikipedia summary

Last updated: July 13, 2026