Question
What is the average IQ by age?
Short answer
The average IQ is 100 at every age. IQ tests compare you only with people your own age, so the middle of each age group is set to 100 by design. A typical 8-year-old, 15-year-old and 60-year-old all score about 100, even though their raw abilities differ a lot.
Want your own number? The test is 25 visual puzzles, about 12 minutes, no sign-up.
Why every age averages 100
Modern IQ tests report a deviation IQ: within each age group, scores are scaled to a mean of 100 and a standard deviation of 15 (Wikipedia: Intelligence quotient). Test makers collect norms for many narrow age bands. A 10-year-old's answers are compared with other 10-year-olds, a 70-year-old's with other 70-year-olds. In every band, the middle score becomes 100. That is why there is no table of rising or falling average IQ by age: it is flat on purpose.
What does change with age
The raw abilities behind the score do move. Large studies find that different abilities peak at different ages: processing speed and some reasoning measures peak in the late teens and twenties, while vocabulary and accumulated knowledge keep rising into the sixties (Hartshorne & Germine, 2015) (Salthouse, 2009). A 70-year-old may solve fewer timed puzzles than a 25-year-old and still earn the same IQ, because each is compared with peers.
Try one · Abstract Reasoning
Which tile completes the grid?
Tap the option you think is right, or show the answer.
Show the answer
The missing tile has a large outlined circle (option 5).
How to solve it
- Start with the first column and name what changes from tile to tile.
- Every row and every column contains each shape (cross, circle and star) exactly once.
- Every row and every column contains each fill (outline, hatched and solid) exactly once.
- The size (large) stays the same in every tile.
- Check the rules on the second column, then apply them to the third.
- So the missing tile has a large outlined circle.
That was 1 puzzle. The full test has 25.
The same score means the same rank at any age
| Score at any age | WAIS-IV label | Higher than about |
|---|---|---|
| 85 | Low Average | 15.9% |
| 100 | Average | 50% |
| 115 | High Average | 84.1% |
| 130 | Very Superior | 97.7% |
Children's scores
Children are tested with tests normed for children, which is one reason a child's score should come from a test built for their age. Online tests for adults, including ours, are not designed to score children. For how scores shift over a lifetime, read IQ and age, does IQ decline with age and at what age intelligence peaks.
Sources
- Intelligence quotient. Wikipedia. en.wikipedia.org/wiki/Intelligence_quotient
- Hartshorne, J. K., & Germine, L. T. (2015). Psychological Science, 26(4), 433-443. doi.org/10.1177/0956797614567339
- Salthouse, T. A. (2009). Neurobiology of Aging, 30(4), 507-514.