Question
How often can you take an IQ test?
Short answer
You can take an online test as often as you like, but repeat scores get inflated by practice. On clinical tests, adults retested on the WAIS-IV after 3 or 6 months gained about 7 Full Scale IQ points from practice alone. American Mensa allows one test or test battery every eight weeks.
Want your own number? The test is 25 visual puzzles, about 12 minutes, no sign-up.
The practice effect
Taking a test teaches you the test. Across cognitive ability tests, retaking raises scores by about a quarter of a standard deviation on average, roughly 4 IQ points, and more when the same form is reused (Hausknecht et al., 2007). On a full clinical battery the effect can be bigger: in a study of 54 adults retested on the WAIS-IV after 3 or 6 months, Full Scale IQ rose about 7 points, with similar gains at both intervals (Estevis et al., 2012). The authors concluded the gains were practice effects, not real change, and could lead to errors in clinical judgment.
How big the effect is depends on several things. A meta-analysis of nearly 1,600 effect sizes found practice effects vary with whether an alternate form is used, the person's age and diagnosis, and the length of the retest interval (Calamia et al., 2012).
Try one · Quantitative Reasoning
Which number comes next?
8, 13, 20, 29, 40, ?
Tap the option you think is right, or show the answer.
Show the answer
The next number is 53 (option 3).
How to solve it
- Find the gaps between neighbors: 5, 7, 9, 11.
- The gaps between the numbers grow by 2 each time.
- So the next gap is 13, and 40 + 13 = 53.
That was 1 puzzle. The full test has 25.
Rules you may run into
- Mensa: American Mensa allows a test or test battery once every eight weeks (American Mensa: testing). See the Mensa admission test.
- Clinical tests: we found no single published minimum interval. If you were tested recently, tell the examiner.
- Online tests: no limit, but each repeat tells you less.
Getting the most from a retake
Treat your first careful attempt as the most informative one. If you retake, read any rise of a few points as practice, and compare ranges rather than single numbers. See does retaking an IQ test raise your score, practice effect and can IQ tests be wrong.
Sources
- Estevis, E., Basso, M. R., & Combs, D. (2012). Effects of practice on the Wechsler Adult Intelligence Scale-IV across 3- and 6-month intervals. The Clinical Neuropsychologist, 26(2), 239-254. doi:10.1080/13854046.2012.659219 pubmed.ncbi.nlm.nih.gov/22353021/
- Calamia, M., Markon, K., & Tranel, D. (2012). Scoring higher the second time around: meta-analyses of practice effects in neuropsychological assessment. The Clinical Neuropsychologist, 26(4), 543-570. doi:10.1080/13854046.2012.680913 pubmed.ncbi.nlm.nih.gov/22540222/
- Hausknecht, J. P., Halpert, J. A., Di Paolo, N. T., & Moriarty Gerrard, M. O. (2007). Journal of Applied Psychology, 92(2), 373-385. doi.org/10.1037/0021-9010.92.2.373
- American Mensa. Admission testing. www.us.mensa.org/join/testing/