— National IQ averages

Average IQ in Guinea-Bissau: 67

Guinea-Bissau has an estimated national IQ average of 67, placing it 33 points below the global mean of 100. This figure comes from cross-national IQ research, primarily Lynn & Vanhanen (2012) and the updated Becker dataset (2019), which compiled standardized cognitive test results across countries.

Where the number comes from

National IQ estimates are not direct measurements of every citizen. They are statistical aggregates built from samples of cognitive testing — school assessments, military induction tests, university entry exams, and standardized international tests like PISA (Programme for International Student Assessment) and TIMSS (Trends in International Mathematics and Science Study). For Guinea-Bissau, the available data places the central estimate at 67, with margin of error typically ±3–5 IQ points depending on sample size and recency.

How Guinea-Bissau compares

The global IQ mean is 100 by convention. Guinea-Bissau's 67 falls below the global average, which corresponds roughly to the 1.39th percentile on the standard IQ distribution (mean 100, SD 15). Within Africa, Guinea-Bissau clusters with countries showing similar developmental and educational profiles.

What drives national IQ differences

Researchers attribute cross-country variation in measured IQ to a combination of factors — none of which are genetic determinism, despite popular misreadings of the data:

• Nutrition. Iodine deficiency, protein-calorie malnutrition in early childhood, and micronutrient gaps depress cognitive development by 5–15 IQ points in affected populations.
• Education access and quality. Years of schooling and quality of instruction account for the largest single factor in measured IQ differences across countries.
• Health and disease burden. Endemic parasitic diseases (malaria, hookworm), childhood infectious disease, and lead exposure all suppress measured IQ.
• The Flynn effect. Measured IQ has risen ~3 points per decade in developing economies as nutrition, schooling, and exposure to abstract reasoning tasks all improve. Guinea-Bissau's figure of 67 reflects current data; the trend line is upward in nearly all countries.
• Test bias and translation. Most IQ tests are calibrated on Western populations. Cross-cultural application introduces measurement error that can shift national averages by ±3–8 points.

What this number does NOT mean

A national average of 67 does not mean every citizen of Guinea-Bissau scores 67. The within-country distribution still has a standard deviation of ~15 points, meaning roughly two-thirds of any country's population scores within 15 points of that country's mean. There are people scoring 140+ in every country and people scoring 70 in every country. Aggregate statistics describe populations, not individuals.

It also does not predict individual outcomes for someone from Guinea-Bissau. Personal IQ depends on a person's own genetics, nutrition, education, and life circumstances — not their country of origin. The variance within countries is much larger than the variance between countries.

How to interpret your own score against the Guinea-Bissau average

• If you score above 82: you are roughly one standard deviation above Guinea-Bissau's national mean — top ~16% of Guinea-Bissau's distribution.
• If you score 52 to 82: you fall within Guinea-Bissau's typical range — roughly the middle 68%.
• If you score below 52: below Guinea-Bissau's mean by about one SD, but still within normal range.

Frequently asked

Other Africa countries

• Egypt
• Libya
• Tunisia
• Algeria
• Morocco
• Sudan

Related reading

• All country IQ averages
• What is the average IQ?
• Full IQ-to-percentile chart
• The Flynn effect explained

Sources: Lynn, R. & Vanhanen, T. (2012), Intelligence: A Unifying Construct for the Social Sciences; Becker, D. (2019), updated national IQ dataset; OECD PISA datasets; IEA TIMSS reports.