The second time you sit any test, something feels different. You know how long the instructions take, you recognise the type of puzzle, and your heart rate is a little lower. Unsurprisingly, your score usually goes up.
So yes, you can practise for an IQ test, and it does make a difference. The more interesting question is how much, what kind of gain it is, and whether it tells you anything about your real ability. Here is the honest answer.
What the practice effect is
Psychologists call the improvement you get from retaking a test the practice effect or retest effect. It is one of the most reliable findings in cognitive testing. Take the same test, or a similar one, a second time and your score will usually rise.
The reasons are mostly ordinary:
- Familiarity with the format. You spend less time working out what each task wants.
- Strategy learning. You discover shortcuts, like checking rows before columns in a matrix puzzle.
- Lower anxiety. A known situation is less stressful, and stress drags on performance. Our guide to test anxiety and IQ explains why.
- Memory for specific items. If the questions are identical, you may simply remember answers.
How much do scores actually shift?
Large reviews that pool many retest studies tend to find gains of a few IQ points on a second attempt, often described as somewhere around a quarter to a third of a standard deviation. On the usual IQ scale, where one standard deviation is 15 points, that works out at very roughly four or five points.
That is an average, and the range is wide. Some people gain more, some gain nothing, and a few score lower the second time. The details matter:
| Factor | Effect on practice gains |
|---|---|
| Identical test vs a different version | Identical tests produce larger gains |
| Short gap between attempts | Larger gains; they shrink as the gap grows |
| Speed-based tasks | Often show bigger practice effects |
| Vocabulary and knowledge tasks | Tend to show smaller gains |
| Coaching on strategies | Can add more on top of simple retesting |
Gains level off fast
A large 2018 meta-analysis of retest effects found that improvement was biggest between the first and second attempt, smaller after that, and largely levelled off after about three attempts. In other words, you cannot practise your way upwards forever. Once the format holds no surprises, the remaining score reflects something closer to your actual reasoning on that test.
Are practice gains "real" intelligence?
Mostly not, and that is not a criticism of you. Researchers have looked at which parts of a test improve with retesting. A well-known 2007 analysis by Jan te Nijenhuis and colleagues found that score gains from retesting did not behave like gains in general intelligence, or g. The tasks that improved most were often not the ones that best measure underlying reasoning.
Put simply, practice makes you better at taking the test. It does not obviously make you better at reasoning about new problems in daily life. If you want to know more about g and why it matters, see our piece on the g factor.
This is why professional assessments are careful about retesting. Clinicians usually leave a decent interval between sittings and note when someone has been tested recently, because a quick retest can overstate ability.
What practising can genuinely help with
None of this means practice is pointless. There are honest reasons to get familiar with IQ-style tasks:
- Removing unfair disadvantages. If you have never seen a matrix puzzle, your first score may underestimate you. A little exposure levels the playing field.
- Reducing anxiety. Knowing what to expect can stop nerves from swallowing time.
- Learning to manage time. Many tests are timed, and pacing is a skill.
- Preparing for a specific assessment. If a job or school uses a reasoning test, knowing the format is reasonable preparation, as long as you follow the rules.
Our overview of the types of IQ puzzle is a good, low-pressure way to get familiar with the main formats.
What practising will not do
It's worth being clear about the limits:
- It won't add 20 points. Large, lasting jumps from short practice are not supported by research.
- It won't transfer far. Getting faster at one puzzle type rarely carries over to unrelated skills.
- It won't make a retake comparable to a first attempt. If you have practised heavily, your score is no longer a clean estimate.
- It won't change your rank on a properly built test much. Good tests use fresh items and norms that account for typical performance.
How to practise sensibly
If you want to prepare without fooling yourself, a few simple rules help.
Use different materials from the real test
Practise on similar puzzle types, not the exact items. This builds familiarity without contaminating the result.
Space your attempts
If you retake a test, leave weeks or months between attempts. Short gaps inflate the gain.
Treat your first proper attempt as your baseline
Your first well-rested, unpractised score on a reputable test is often the most informative. After that, interpret any rise with caution.
Look after the basics
Sleep, a calm environment and a clear head do more for a fair score than cramming. A tired brain underperforms no matter how much you have practised.
Why online scores can drift
Online tests are especially prone to practice effects, because people often take several in a row, sometimes with similar or identical items. If your score climbed with each attempt, that is likely familiarity, not a sudden rise in intelligence.
If you want a cleaner reading, take our free IQ test when you are rested, in one sitting, without having just done several others. Then treat that number as your reference point.
The bottom line
You can practise for an IQ test, and doing so usually adds a few points, mostly on the second attempt. Those gains come from familiarity and lower anxiety rather than a change in underlying ability, and they level off quickly. A little preparation is fair; heavy repetition just makes the score less meaningful.
FAQ
How many points can practice add to an IQ score?
Studies typically find gains of a few points on a retest, very roughly four or five on average, with large individual differences. Gains shrink with each further attempt.
Is it cheating to practise for an IQ test?
Getting familiar with the format is generally fine and can make results fairer. Memorising the actual questions of a test you will sit, or breaking a test's rules, is a different matter.
How long should I wait before retaking an IQ test?
Longer gaps reduce practice effects. Professional assessments usually wait a substantial period, often a year or more, before retesting with the same instrument.
Does practising IQ puzzles make you smarter?
It makes you better at those puzzles. Evidence that this improves general reasoning in everyday life is weak.
