— Education & cognition
PhD holders — average IQ
Published data on cognitive ability by educational attainment consistently places phd holders at an average IQ around 125 — the 95th percentile of the general adult population.
PhD holders average around the top 5% of the cognitive distribution. Field varies substantially: physics and mathematics PhDs average ~130, education and counselling PhDs closer to 115.
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 phd holders scoring well above 140
- And many phd holders scoring well below 110
- Lifetime achievement correlates with conscientiousness, motivation, opportunity, and circumstance — not just IQ
Compare with other education levels
- High school dropouts — average IQ 87
- 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