Countries With the Lowest Average IQ
If you see a list of countries with the lowest average IQ, it is tempting to read the last number as a fact about an entire population. The more accurate answer is narrower: one 2025 online dataset reported its lowest included country averages from 83.84 to 89.57, but those figures describe people who chose to take that particular test online, not every resident of those countries.
That distinction changes how the ranking should be used. The table is useful for understanding what one dataset observed. It is not a league table of human worth, a diagnosis of a country, or evidence that one nationality is born less intelligent than another. Below, we separate the reported numbers from what they can—and cannot—tell you.
Which countries had the lowest reported averages?
The table below reproduces the bottom ten countries that appeared in the International IQ Test’s 2025 results. The site says the ranking used tests taken between January 1 and December 31, 2025, after screening for likely repeat attempts, bots, and suspicious responses. These are reported online-test averages, not official national IQ statistics.
| Rank in the dataset | Country | Reported average | Participants |
|---|---|---|---|
| 128 | Tanzania | 89.57 | 252 |
| 129 | Afghanistan | 89.31 | 212 |
| 130 | Democratic Republic of the Congo | 88.60 | 200 |
| 131 | Uganda | 88.49 | 379 |
| 132 | Gabon | 88.35 | 109 |
| 133 | Angola | 87.89 | 473 |
| 134 | Nicaragua | 87.75 | 225 |
| 135 | Rwanda | 86.90 | 203 |
| 136 | Timor-Leste | 86.70 | 152 |
| 137 | Somalia | 83.84 | 141 |
The ranking excludes countries with fewer than 100 participants from its main table, yet several entries above still have only about 100–250 test takers. A difference of a few points can therefore reflect who happened to participate, how the site reached that country, or ordinary sampling noise. The source itself warns that internet access and voluntary participation limit representativeness.
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Does “lowest average IQ” mean a country is less intelligent?
No. A country-level average is a statistic about a sample and a test, not a property carried by every person in the country. IQ tests are also normed: a conventional IQ scale is centered around a mean of 100 with a standard deviation of 15. A score of 84 in an online sample does not mean that 84 is the fixed cognitive capacity of a nation.
There are three separate questions that are often collapsed into one headline:
- What did this sample score? This is what the online ranking can describe.
- How representative was the sample? This depends on recruitment, internet access, age, education, language, and motivation.
- What abilities did the test measure? Raven-style matrix items emphasize nonverbal pattern reasoning; they do not measure every verbal, practical, social, or emotional ability.
The International IQ Test describes its assessment as inspired by Raven’s Progressive Matrices and labels the result an estimate rather than a clinical diagnosis. That is a sensible way to read the table: as a snapshot of performance on one format, under one set of participation conditions.
Why can country averages differ so much?
Differences in observed scores can reflect opportunity and measurement conditions as much as cognitive ability. Education, health, nutrition, language, test familiarity, and access to technology all affect who can take a test and how they perform.
| Factor | Why it can influence a country comparison |
|---|---|
| School access and quality | Years of schooling and practice with abstract problems affect measured reasoning and test-taking strategies. |
| Internet access | Online rankings omit people who cannot reliably reach the website; coverage also differs by region and income. |
| Language and instructions | Even nonverbal tests require instructions, navigation, and sustained attention in a language the participant understands. |
| Health and nutrition | Early-life health affects development. WHO notes that serious iodine deficiency during pregnancy and childhood can impair brain development and cognitive capacity. |
| Age and self-selection | A country may be overrepresented by students, technology enthusiasts, or people curious about IQ tests rather than a balanced population sample. |
| Test design | Matrix reasoning captures some abilities but not vocabulary, acquired knowledge, creativity, judgment, or social intelligence. |
These factors do not make every comparison meaningless. They do mean that a ranking should not be treated as a causal explanation. A lower observed average can point to unequal conditions around learning and assessment without proving that citizens have lower innate potential.
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How should you compare IQ rankings with PISA results?
Use them as different measurements, not interchangeable scoreboards. OECD’s PISA assesses the knowledge and skills of 15-year-old students in mathematics, reading, and science. An online IQ table usually combines self-selected participants across ages and reports a standardized reasoning score. PISA includes sampling and quality procedures designed for education-system comparisons; an online test has different strengths and limitations.
If your question is about schools, learning outcomes, or education policy, PISA and national assessment data are usually more appropriate. If your question is about how a particular online test performed, the IQ ranking is the relevant source—but only with its participant count and methodology beside it.
What is a better way to read a low score?
Start with the dataset, not the label. Check the year, number of participants, test format, exclusion rules, and whether the sample was recruited randomly. Then ask whether a different source measures the outcome you actually care about.
For an individual, a professionally administered assessment with age-appropriate norms is far more informative than using a country ranking to guess personal ability. For a country, look at several indicators together: school attendance, PISA or other achievement data, health measures, nutrition, income, and access to learning. No single number can summarize a population’s intelligence.
The most responsible conclusion is therefore modest: in this 2025 online dataset, Somalia had the lowest reported included average at 83.84, followed by Timor-Leste at 86.70 and Rwanda at 86.90. Those values should be read as sample results with substantial uncertainty—not as a verdict on the people who live there.
Q: Which country has the lowest average IQ?
A: Somalia had the lowest reported included average in the 2025 International IQ Test dataset, at 83.84. Only 141 participants were recorded, so the figure should not be treated as a national population estimate.
Q: Are national IQ rankings scientifically reliable?
A: They vary in quality and are not automatically representative. Online rankings are affected by voluntary participation and internet access, while older national-IQ datasets have been criticized for small, selective, and incomparable samples.
Q: Does a low country average prove low genetic intelligence?
A: No. A group average cannot establish an individual’s ability or explain causes. Education, health, nutrition, language, sampling, and test design can all affect the observed result.
Q: Is PISA an IQ test?
A: No. PISA measures 15-year-old students’ performance in mathematics, reading, and science; it is not an IQ test and should not be converted directly into IQ points.
References
- International IQ Test: Average IQ by Country 2026
- International IQ Test: Methodology and Mission
- OECD: PISA 2022 Results, Volume I
- Sear, R. (2022), National IQ datasets and data quality
Last updated: July 18, 2026
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