— MBTI & IQ Research
ISFJ IQ — what's the average for The Defender?
The average reported IQ for ISFJ (The Defender) across published MBTI cognitive studies sits around 108 — placing the typical ISFJ in the 70th percentile of the general population.
ISFJs typically score in the average to high-average range, with strongest performance on verbal and applied tasks.
Why ISFJs tend to score where they do
→Pause. Find out YOUR IQ before you keep reading.MBTI type is not a measurement of intelligence — it's a personality typology rooted in Jung's cognitive function theory. But certain dominant function patterns correlate with cognitive task performance:
- Introversion — tends to favour deep, sustained processing of abstract material
- Sensing (S) — correlates with strong applied and concrete reasoning, often outperforming N types on numeric and spatial subtests
- Feeling (F) — correlates with verbal-conceptual reasoning strength
- Judging (J) — has the weakest individual correlation with IQ; matters more for working style than raw ability
The honest caveat
→Curious how YOU score? 20-min calibrated test.Average IQ by MBTI type is a statistical tendency, not a rule. The standard deviation within any single type is typically 12-15 IQ points — which means there are ISFJs scoring well above 145 and ISFJs scoring below 90. The type tells you nothing about any individual's actual cognitive ability.
If you want to know YOUR actual IQ rather than the average for your MBTI type, take a properly calibrated test that uses real psychometric scoring (IRT 3PL Bayesian MAP estimation) rather than a quick quiz.
How ISFJ compares to other types
→The numbers above? Find out where YOU land.- ESFP — average IQ 108 (The Entertainer)
- ESFJ — average IQ 107 (The Consul)
- ISFP — average IQ 109 (The Adventurer)
- ISTJ — average IQ 110 (The Logistician)
- ESTJ — average IQ 111 (The Executive)