Average IQ in Bulgaria: What the Evidence Really Shows

What did Bulgaria score in PISA 2022?

The OECD Education GPS reports that Bulgarian 15-year-olds averaged 417 points in mathematics, 404 in reading, and 421 in science. The OECD averages were 472, 476, and 485 respectively. PISA measures how students apply knowledge, solve problems, think critically, and communicate in a defined assessment; it is not a clinical IQ test.

The proficiency distribution adds context. Forty-six percent of Bulgarian students reached at least Level 2 in mathematics, compared with 69% across the OECD. In reading, 47% reached Level 2 or higher, compared with 74% across the OECD. In science, 52% reached that baseline, compared with 76% across the OECD.

Only 3% of Bulgarian students were top performers at mathematics Levels 5 or 6, 2% reached reading Level 5 or higher, and 1% reached science Levels 5 or 6. Level 2 and Level 5 are thresholds for particular PISA tasks. They do not translate into IQ cutoffs, and they do not imply that students outside the tested sample lack ability.

How did Bulgaria’s results change over time?

The OECD says Bulgaria’s 2022 results were lower than in 2018 in mathematics and reading and about the same in science. Across the full PISA series, the 2022 means were among Bulgaria’s lowest observed in all three subjects. Compared with 2012, the share below Level 2 increased by nine percentage points in mathematics, 13 points in reading, and 11 points in science.

These are important signals for education policy, but they are not evidence that Bulgarians’ innate intelligence fell by the same amount. Test performance changes with curriculum, school attendance, teacher resources, health, economic conditions, motivation, and how familiar students are with the assessment. A trend in school achievement should not be relabeled as a trend in national IQ.

What do Bulgaria’s official education statistics show?

The National Statistical Institute’s Education in the Republic of Bulgaria 2023 summarizes comprehensive surveys covering the 2023/2024 school year. It reports 216.9 thousand children enrolled in pre-primary education. In 2023, 63.4 thousand students completed basic education, while 24.2 thousand completed general upper-secondary programmes and 15.4 thousand completed vocational programmes.

These counts are administrative and educational indicators. A larger or smaller graduating cohort can reflect population size, migration, enrollment, retention, or demographic change. None is a measure of general intelligence. The NSI also publishes net-enrollment rates, but a rate still describes participation in an age group rather than a cognitive score.

Why do education results vary within Bulgaria?

Bulgaria is not a single classroom. District, school type, family resources, language, rural or urban location, health, and access to qualified teachers can all influence whether a student encounters the material assessed by PISA. The OECD’s country note reports that socioeconomic status is related to performance, so a national mean combines students with very different learning conditions.

PISA also reports a gap between the highest- and lowest-performing students. Bulgaria’s smaller share of students reaching baseline proficiency and its small top-performing share describe the distribution of demonstrated skills in the sample. They do not justify labeling a whole population as less intelligent, nor do they predict an individual student’s future.

The 2022 assessment met PISA’s quality standards for Bulgaria and was considered fit for reporting. That strengthens the education conclusion—what sampled 15-year-olds did on PISA tasks—but it does not expand the population to adults or convert the test into an IQ battery.

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Can PISA or graduation data be converted into Bulgaria’s IQ?

No accepted conversion can do this reliably. PISA uses item-response models and an international achievement scale. IQ tests use different tasks, age norms, constructs, and reference populations. Graduation and enrollment data are counts or percentages with no common score scale.

A formula could be designed to output a familiar-looking 100-based number, but it would depend on assumptions about schooling, language, test selection, and people who were not represented. The result would be a model based on educational performance, not a newly observed national IQ. High-quality sampling improves confidence in the original indicator; it does not make an invalid conversion valid.

How should readers interpret Bulgaria’s data fairly?

Ask a question the evidence can answer: “How did Bulgarian 15-year-olds perform on PISA tasks in 2022?” or “How many students completed general upper-secondary education in 2023?” Those questions have documented answers. “How intelligent are Bulgarians?” is not answered by a PISA mean or a graduation count.

For an individual score, use an age-appropriate, properly normed assessment under standard conditions and in a language the person understands well. For policy, combine PISA with attendance, teacher resources, health, household conditions, and regional statistics. For international comparisons, check the year, population, instrument, language, participation, and uncertainty before accepting a country ranking.

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Q: What is the average IQ in Bulgaria?

A: There is no authoritative single national IQ average for Bulgaria. Online estimates often combine different tests, samples, and years, so they should not be treated as a representative population measurement.

Q: What were Bulgaria’s PISA 2022 scores?

A: Bulgarian 15-year-olds averaged 417 in mathematics, 404 in reading, and 421 in science. These are PISA achievement scores, not IQ points; the OECD comparison means were 472, 476, and 485.

Q: How many Bulgarian students completed upper-secondary education?

A: The National Statistical Institute reports 24.2 thousand general-programme graduates and 15.4 thousand vocational-programme graduates in 2023. These are completion counts, not measures of intelligence.

Q: Does Bulgaria’s PISA result measure intelligence?

A: No. PISA measures applied reading, mathematics, and science in a sampled age group. Schooling, language, resources, health, motivation, and test familiarity also affect performance.

Q: Can Bulgaria’s PISA score be converted into an IQ?

A: No accepted conversion is scientifically reliable. PISA and IQ tests use different tasks, scales, norms, and purposes, so a conversion would create false precision.

References

• OECD. PISA 2022 Results: Country Note for Bulgaria.
• OECD. Education GPS: Bulgaria — Student performance.
• National Statistical Institute of Bulgaria. Education in the Republic of Bulgaria 2023.
• National Statistical Institute of Bulgaria. Education in the Republic of Bulgaria, 2023/2024 school year.

Last updated: July 19, 2026