Which Country Has the Highest Average IQ? Why the Answer Changes With the Dataset

South Korea ranks first among sovereign countries in one major 2026 online IQ dataset. Yet Hong Kong scores even higher when reported separately, while older research tables put Japan first.

In the International IQ Test’s 2026 ranking, South Korea has the highest average IQ among the sovereign countries in the official table, at 106.97. China is second at 106.48 and Japan third at 106.30. The same source separately reports Hong Kong at 107.73, above every sovereign-country result, which is why some ranking pages may show Hong Kong in the top position.

That answer comes with an important qualifier: there is no official global IQ census. Different country-IQ rankings use different samples and methods, so “which country has the highest IQ?” does not have one permanent answer. Our Average IQ by Country guide provides the full 2026 country table and explains the competing datasets in detail.

The Top 10 Countries in the 2026 Online IQ Ranking

The current International IQ Test table is based on 1,212,714 people who took the same online IQ test during 2025. Countries with fewer than 100 participants were excluded from the official ranking.

Because everyone took the same test, this ranking avoids one major problem of older national-IQ compilations: mixing many different cognitive tests together. It still has a serious limitation. Participants chose to take an online IQ test, so they are not a random sample of each country’s entire population. The source itself flags internet-access bias and large differences in participation between countries.

What About Hong Kong, Taiwan, and Macao?

This is where apparently contradictory rankings often begin.

The same 2026 source reports several territories separately: Hong Kong 107.73, Macao 106.32, and Taiwan 105.80. Hong Kong’s figure is higher than South Korea’s 106.97. However, the source’s official global country ranking handles these territories under sovereign-country classifications while still publishing their separate results.

So two statements can both describe the same source correctly:

• South Korea is #1 in the official sovereign-country ranking.
• Hong Kong has the highest separately reported score.

If a ranking page treats Hong Kong as its own ranked economy, Hong Kong may appear first. If it restricts the list to sovereign countries, South Korea appears first.

Why Older IQ Rankings Often Put Japan First

The famous Lynn–Becker 2019 national-IQ dataset uses a very different method. It combines results from many separate studies conducted with different tests, age groups, years, and sampling methods. In that dataset, commonly repeated estimates put Japan at 106.48, Taiwan at 106.47, and Singapore at 105.89.

Those values still appear on many websites, which is why searches for the “highest IQ country” may return Japan even when newer pages show South Korea or Hong Kong.

The quality of those compiled estimates is disputed. Rebecca Sear’s analysis of the 2019 dataset argued that many source samples were small, unrepresentative, based on different tests, or otherwise unsuitable for precise worldwide comparisons. Russell Warne’s later review took a more moderate view, arguing that national mean IQ estimates have shortcomings that should constrain how they are interpreted, while rejecting the idea that every use of the data is automatically worthless.

Which Ranking Should You Trust?

The 2026 same-test dataset has a major practical advantage: more than a million people took the same test under the same scoring system. That makes country-to-country test format more consistent.

Its weakness is selection. People who voluntarily take online IQ tests may differ from their country’s general population in education, internet access, age, interest in cognitive testing, and motivation. A country with 229,918 participants is also represented very differently from a country with a few hundred.

The older compiled datasets have the opposite profile. They draw from a broader research literature, but the component studies vary greatly in representativeness and measurement. That is why Cognitive Train’s full country IQ ranking keeps these source families separate.

Cross-cultural measurement adds another layer. Language, familiarity with testing, schooling, and whether items work equivalently across groups can matter. See Are IQ Tests Culturally Biased? for how those issues are studied.

Singapore Leads a Different Kind of International Comparison

IQ tables are not the only way countries are compared on cognitively demanding tasks.

In OECD PISA 2022, Singapore scored significantly higher than every other participating country or economy in mathematics, reading, and science. PISA assesses 15-year-old students using standardized international sampling and testing procedures.

PISA measures academic competencies, not general IQ. Its results are still useful because they show how strongly the answer to “which country is smartest?” depends on what you decide to measure. South Korea leads one current online IQ ranking; Hong Kong has the highest separately reported score in that source; Japan leads a famous older compiled IQ dataset; Singapore leads PISA 2022.

Does the Highest National Average Mean the Smartest People?

No country average tells you much about a particular person.

IQ scores within every country spread widely. The difference between two individuals from the same country can be far larger than the difference between two national averages. Rankings also move over time as samples, education, health, migration, technology, and test participation change.

A national average therefore describes a group result under a particular measurement system. It does not define anyone’s potential, and it cannot establish why two populations differ. Our article on whether IQ is genetic or learned explains why population comparisons cannot be reduced to a simple genes-versus-environment answer.

What Does an IQ of 106 or 107 Mean?

On the familiar IQ scale, 100 is the average and the standard deviation is usually 15. A score around 106 or 107 is only modestly above that center point. See our Average IQ guide and IQ Score Chart for percentile context.

The decimal places in national rankings can make differences look more meaningful than they are. A gap such as 106.97 versus 106.48 should not be read like the final score of a sporting event. Sampling uncertainty and who took the test matter much more than a few tenths of a point.

Check Your Own Approximate IQ

If you are curious about your own reasoning profile, Cognitive Train’s IQ-Style Test gives an approximate estimate across several reasoning-related abilities. Your result is much more relevant to you than the average attached to your passport.

You can also browse Cognitive Train’s brain tests and cognitive assessments for more targeted measures.

The Bottom Line

If you mean the current 2026 same-test ranking of sovereign countries, South Korea is first at 106.97. If separately reported territories are included, Hong Kong’s 107.73 is higher. If you use the widely circulated Lynn–Becker 2019 compiled dataset, Japan comes first at 106.48.

Those different winners are the point: “highest average IQ” is a property of a dataset and its rules, not a permanent title held by a country. For the broader picture, explore Cognitive Train’s Intelligence & IQ guides or read what IQ actually measures. You can also use our brain training and cognitive training tools to practice specific abilities directly.