FAQ
Does IQ change with age?
Your IQ score stays fairly stable with age because tests are age-normed. You are always compared with people in your own age group, so the average is 100 at every age. Your raw mental abilities do shift over life, but the scoring adjusts for that automatically.
Why is the average IQ 100 at every age?
The average is 100 at every age because of age-norming, where your answers are scored against others of the same age. This removes the effect of normal age-related changes from the final number. So a sharp 70-year-old and a sharp 20-year-old can both score 100 relative to their peers.
How do fluid and crystallized intelligence differ over the lifespan?
Fluid reasoning peaks in the late teens to mid-20s and then slowly declines, while crystallized knowledge keeps rising into the 60s. That is why older adults often lose a little speed on novel puzzles yet gain decades of vocabulary and knowledge. Age-norming keeps the overall IQ centered at 100 despite these opposite trends.
This is an educational estimate for self-understanding, not a clinical diagnosis.