Countries With the Highest Average IQ

Why do these countries rank so high?

The honest answer is that high national scores track the things that build cognitive skill in childhood and let people show it on a test. None of the leading explanations is about genes.

Schooling that emphasises reasoning. The East Asian systems that dominate the ranking also dominate the OECD's PISA study of 15-year-olds in maths, reading and science. Long school years, near-universal enrolment, heavy investment in maths, and a culture of extra tutoring all build exactly the abstract-reasoning skills that IQ tests reward.

Nutrition and health. Adequate iodine, iron and protein in early childhood, plus low rates of childhood disease, protect brain development. Countries that fixed malnutrition and controlled infectious disease over the last century saw measured intelligence climb with them.

Familiarity with testing. Places where children sit standardised, timed, multiple-choice exams from a young age produce adults who are simply better at the format. That is a real advantage on the test, but it is a testing-skill advantage, not proof of deeper ability.

Wealth and stability. Higher income tends to travel with all of the above: better schools, clinics, clean water and smaller families with more resources per child. The correlation between national IQ figures and GDP is one of the most cited findings in this field, and it runs in both directions.

The Flynn effect: scores rose everywhere

The single most important fact for keeping this ranking in perspective is the Flynn effect. Across the twentieth century, average IQ scores rose by roughly three points per decade in more than a dozen countries, adding up to around 30 points over a century. The researcher James Flynn documented it systematically, and it is now understood to be environmental, not genetic, because populations cannot change their genes that fast.

Two details matter here. First, the gains were largest on fluid, abstract-reasoning tests such as Raven's matrices and smallest on vocabulary, which is the opposite of what more schooling alone would predict, so several forces are at work: better nutrition, smaller families, less childhood disease and a more visually and abstractly demanding modern environment. Second, since the 1990s the rise has slowed or reversed in several wealthy countries. The upshot is simple. If an entire population can gain 30 points in a lifetime from better conditions, then a seven-point gap between countries today says a lot about conditions and very little about potential.

How reliable are these numbers?

Treat the whole ranking as a rough sketch. The most influential source, Richard Lynn and Tatu Vanhanen's IQ and the Wealth of Nations and its successor The Intelligence of Nations, is also the most criticised.

The core problem is data coverage. Reviewers note that for many nations the authors had no local study at all and estimated the value from neighbouring countries, while a large share of the remaining figures rest on a single study, sometimes with small or unrepresentative samples such as only children, only one city, or only one age group. On top of that, academics have challenged the methods and conclusions directly. In 2020 the European Human Behaviour and Evolution Association issued a formal statement opposing the use of Lynn's national IQ dataset on methodological grounds.

The newer online figures have the opposite problem: huge samples, but self-selected internet users who chose to take an IQ test, which is nothing like a representative national sample. Add genuine issues of cultural and language bias in the test items themselves, and you have numbers that are useful for a bird's-eye view and misleading if read to the decimal. That is why every serious version of this list, including this one, comes wrapped in caveats.

FAQ

Q: Which country has the highest average IQ?

A: Hong Kong and South Korea usually top the list, at around 107. The exact leader depends on the dataset; the classic Lynn and Vanhanen estimates place Singapore and Hong Kong first near 108, while 2026 online-test compilations put Hong Kong, South Korea, China and Japan in the top four. All of them sit within a couple of points of each other.

Q: Why do East Asian countries score highest?

A: Because of environment, not genes. Intensive schooling with a heavy maths focus, strong early-childhood nutrition and health, and deep familiarity with timed standardised tests all raise measured IQ. These same countries lead the OECD's PISA education rankings for the same reasons.

Q: Are these country IQ rankings scientifically reliable?

A: Only as rough estimates. Many national values come from a single small study or are inferred from neighbouring countries, and the most cited dataset has been formally criticised by academic bodies. Sampling gaps, cultural test bias and self-selected online participants all limit how much weight any single ranking can carry.

Q: Does a high national average mean an individual from that country is smarter?

A: No. A national average is a summary of millions of people with an enormous range inside it. The variation between individuals within any country dwarfs the few-point gap between country averages, so the ranking tells you nothing reliable about any one person.

References

• World Population Review — Average IQ by Country 2026
• Wikipedia — IQ and the Wealth of Nations (methodology and criticism)
• Lynn & Becker — The Intelligence of Nations (Ulster Institute)
• The Flynn Effect: A Meta-analysis (PMC)

Last updated: July 13, 2026