Average IQ in Wales: What PISA 2022 Can—and Cannot—Tell Us

What did Wales score in PISA 2022?

Wales scored below the OECD average in all three PISA domains, with the largest gap in science. The Welsh Government's national report gives these means:

These figures summarize a probability sample of 15-year-olds, not every person in Wales. The assessment age window is approximately 15 years and 3 months to 16 years and 2 months. Some pupils can be excluded when they have not had sufficient experience in English or Welsh, have additional learning needs that prevent participation, or meet other PISA criteria. The results therefore answer an education-system question, not a question about innate intelligence.

How strong is the Wales sample?

The Welsh Government says the sample is broadly representative, but the 2022 results require caution. The final sample included 89 schools and 2,568 learners. The weighted school response rate was 71.3% after replacement, and the learner response rate was 74.6%, below the OECD's preferred target. Lower-attaining schools were initially underrepresented and higher-attaining schools overrepresented; weighting reduced, but cannot erase, that possible bias.

This is not a reason to discard PISA. It is a reason to describe the result as an estimate with uncertainty rather than as a precise national ranking. The Welsh Government and OECD both advise caution when interpreting comparisons and trends because the sampling standards were not fully met. A six-point difference in mathematics should not be retold as a six-point IQ difference.

What changed from 2018 to 2022?

All three Wales means were lower in 2022 than in 2018, with the clearest decline in reading. The Welsh Government reports:

The change is an education-outcome trend, not proof that the intelligence of Welsh people changed. The COVID-19 disruption, school closures, curriculum, wellbeing, participation, and learning support may all affect an assessment taken in 2022. The current Curriculum for Wales was also not what PISA 2022 was designed to assess. Trends need confidence intervals and context before anyone can say how much of a difference is meaningful.

What do proficiency levels show?

The distribution tells more than a single mean. In mathematics, 32% of Welsh learners were below Level 2, while 6% reached Levels 5 or 6. The corresponding OECD shares were 31% below Level 2 and 9% at Levels 5 or 6. In reading, 29% of Welsh learners were below Level 2 and 5% reached Levels 5 or 6, compared with 26% and 7% across the OECD. In science, 6% reached the top two levels, compared with 7% across the OECD.

PISA Level 2 is a performance threshold on PISA tasks. It is not an IQ cutoff, a diagnosis of learning disability, or a label for an individual child. A mean can stay similar while the spread of performance changes, so distributions and subgroup context are essential.

How do language, background, and opportunity matter?

PISA results reflect learning opportunities and the conditions in which pupils take the test. The 2022 report identifies about 9% of Welsh learners as having an immigrant background, although background was unknown for 16%. In the mathematics data, pupils with no immigrant background averaged 468, first-generation immigrant pupils 481, second-generation pupils 481, and the group with unknown background 450. These are descriptive group means, not evidence of fixed ability differences.

Wales is bilingual, and students' experience with English or Welsh can affect how an assessment is understood. PISA attempts to provide standardized instruments, but it cannot remove every difference in language exposure, curriculum, home resources, attendance, or familiarity with testing. Those factors are precisely why an education score cannot be treated as an IQ estimate.

Related

Average IQ in Europe: How the Continent Compares

The average IQ in Europe is estimated at roughly 97 to 100 on a scale where the global mean is 100, with most countries clustered in the high 90s to low 100s.

Is a PISA score the same as an IQ score?

No. There is no valid conversion from 466 PISA mathematics points to an IQ of 99, 100, or any other value. PISA evaluates how 15-year-olds use learned knowledge in realistic mathematics, reading, and science situations. A professional IQ assessment samples cognitive tasks such as verbal reasoning, visual-spatial reasoning, working memory, and processing speed, then interprets an individual's result against an age-appropriate norm group.

The scales, purposes, samples, and error estimates differ. Rescaling PISA means to a 100/15 IQ distribution would be an invented statistic. It would also hide the effect of curriculum, language, school access, and the fact that PISA includes only a narrow age cohort.

Why do online Wales IQ estimates disagree?

Online estimates combine unlike tests and non-random participants. One site may average visitors who choose a timed matrix puzzle; another may reproduce a country table built from older school samples or a statistical model. Participants are more likely to have internet access, understand the test language, enjoy puzzles, and be curious about IQ. These selection effects are not corrected simply by collecting more voluntary attempts.

Before trusting a number, check the test, norm group, age range, recruitment method, year, exclusions, weighting, and uncertainty interval. If those details are missing, the figure should be treated as an informal estimate, not a measured national fact.

How can someone in Wales get a meaningful IQ result?

Use an age-appropriate, validated assessment administered under standard conditions by a qualified professional. Ask which Welsh or English norms apply, what question the assessment is intended to answer, and how the evaluator will explain confidence intervals and subtest patterns. School history, language exposure, attention, hearing, vision, health, and educational support should be considered.

An online quiz can be useful practice or entertainment, but it should not be used alone for diagnosis, school placement, employment decisions, or comparisons between nations. A responsible report identifies the test version, administration conditions, norm group, uncertainty, and abilities that were actually measured.

Related

What Is the Average IQ in the World?

Every IQ test is normed so its population averages 100, yet cross-country estimates put the global average human IQ around 82 to 90 — here is why they differ.

Q: What is the average IQ in Wales?

A: There is no official, current all-age national IQ average for Wales. PISA 2022 provides learning scores for sampled 15-year-olds, not one IQ mean for every Welsh resident.

Q: What were Wales's PISA 2022 scores?

A: Wales averaged 466 in mathematics, 466 in reading, and 473 in science. The OECD averages were 472, 476, and 485 respectively; these are achievement scores, not IQ points.

Q: Can I convert the Wales PISA score into IQ?

A: No. PISA and IQ tests use different constructs, samples, norms, and scales. There is no scientifically valid conversion formula.

Q: Why should Wales's PISA results be interpreted cautiously?

A: The Welsh Government reports response rates below OECD targets and possible differences in school participation. Weighting helps, but comparisons and trends still carry uncertainty.

Q: How can I measure IQ in Wales?

A: Choose a validated, properly normed assessment administered under standard conditions by a qualified professional. Interpretation should include language, age norms, confidence intervals, and the limits of the instrument.

References

• Welsh Government. Achievement of 15-year-olds in the Programme for International Student Assessment (PISA): national report, 2022.
• Welsh Government. PISA 2022 national report for Wales (PDF).
• OECD. How did countries perform in PISA 2022?.
• American Psychological Association. IQ definition.

Last updated: July 19, 2026