— Education & cognition
High school dropouts — average IQ
Published data on cognitive ability by educational attainment consistently places high school dropouts at an average IQ around 87 — the 19th percentile of the general adult population.
People who don't complete high school average around the 19th percentile on cognitive measures. This is a population average, not a deterministic floor — many high school non-completers score well above 100 due to circumstantial rather than cognitive reasons.
What this average really tells you
Education-by-IQ averages reflect selection effects, not causation. Higher-IQ people are more likely to be admitted to and complete higher levels of education, so the averages compound through filtering at each stage:
- Completing high school
- Being admitted to college
- Completing a bachelor's degree
- Being admitted to graduate school
- Completing a graduate degree
Each stage filters more strongly on cognitive ability, which is why average IQ rises monotonically with educational attainment.
What it does NOT tell you
An education-level average is not a cap or a requirement:
- There are many high school dropouts scoring well above 102
- And many high school dropouts scoring well below 72
- Lifetime achievement correlates with conscientiousness, motivation, opportunity, and circumstance — not just IQ
Compare with other education levels
- High school graduates (no college) — average IQ 97
- Some college (no degree) — average IQ 104
- Bachelor's degree holders — average IQ 113
- Master's degree holders — average IQ 117
- PhD holders — average IQ 125