Question
At what age can a child take an IQ test?
Short answer
Clinical IQ tests start at about age 2. The Stanford-Binet 5 covers ages 2 and up, and the WPPSI-IV starts at 2 years 6 months. School-age children usually take the WISC-V (ages 6 to 16). Scores at young ages are less stable, and testing should be done by a qualified professional.
Want your own number? The test is 25 visual puzzles, about 12 minutes, no sign-up.
Which test fits which age
| Test | Ages |
|---|---|
| Stanford-Binet 5 | 2 to 85 and older (PRO-ED: SB5) |
| WPPSI-IV | 2:6 to 7:7 (Pearson: WPPSI-IV) |
| KBIT-2 (brief) | 4 to 90 (Pearson: KBIT-2) |
| WISC-V | 6:0 to 16:11 (Pearson: WISC-V) |
| WAIS-5 | 16 to 90 |
The WPPSI-IV adjusts for the age of the child: its core subtests take 30 to 45 minutes at ages 2:6 to 3:11 and 45 to 60 minutes at ages 4 to 7:7 (Pearson: WPPSI-IV).
Try one · Spatial Reasoning
Which option is the same shape, only rotated?
Tap the option you think is right, or show the answer.
Show the answer
Option 2 is the original figure turned a half turn.
How to solve it
- Pick a landmark: the marked cell or the end of the longest arm.
- Turn the figure in your head and watch where that landmark goes, and which side the other cells end up on.
- Turning the figure a half turn gives option 2.
- Each of the other options is a mirror image: flipping it over would match, but no turn does.
That was 1 puzzle. The full test has 25.
Young scores are less settled
A score from early childhood is a snapshot. In a large twin sample, the heritability of general cognitive ability rose from 41% at age 9 to 66% at age 17 (Haworth et al., 2010), one sign that differences between children keep developing through school. That is a good reason to treat a preschool score as provisional.
Reasons families seek testing
- Gifted program screening, where schools often use group tests such as the CogAT.
- Questions about learning or development, where a psychologist gives an individual test.
- Mensa: American Mensa's own test starts at 14 and British Mensa's supervised test at 10 1/2, but both accept professionally given tests as prior evidence (American Mensa: qualifying scores) (British Mensa: test your IQ).
A note on online tests for children
IQ is always scored against people of the same age, so a test normed on adults cannot give a child a meaningful IQ. See the average IQ by age and what gifted means.
Sources
- Roid, G. H. Stanford-Binet Intelligence Scales, Fifth Edition (SB5), PRO-ED product page. 2003. proedinc.com/products-13290.html
- Pearson. Wechsler Preschool and Primary Scale of Intelligence, Fourth Edition (WPPSI-IV), product page. 2012. www.pearsonassessments.com/store/usassessments/en/Store/Professional-Assessments/Cognition-%26-Neuro/Wechsler-Preschool-and-Primary-Scale-of-Intelligence-%7C-Fourth-Edition/p/100000102.html
- Pearson. Wechsler Intelligence Scale for Children, Fifth Edition (WISC-V), product page. 2014. www.pearsonassessments.com/store/usassessments/en/Store/Professional-Assessments/Cognition-%26-Neuro/Wechsler-Intelligence-Scale-for-Children-%7C-Fifth-Edition/p/100000771.html
- Pearson. Kaufman Brief Intelligence Test, Second Edition (KBIT-2), product page. www.pearsonassessments.com/store/en/usd/p/100000390.html
- Haworth, C. M. A., et al. (2010). The heritability of general cognitive ability increases linearly from childhood to young adulthood. Molecular Psychiatry, 15(11), 1112-1120. doi.org/10.1038/mp.2009.55
- American Mensa. Admission testing. www.us.mensa.org/join/testing/
- American Mensa. Qualifying test scores. www.us.mensa.org/join/testscores/qualifying-test-scores/
- British Mensa. Test your IQ / book a test. mensa.org.uk/test-your-iq/