Guide
Culture-fair IQ tests
A culture-fair IQ test tries to measure reasoning without leaning on language, schooling or knowledge that some people have and others do not. It is a worthwhile aim with real limits. Here is how these tests work, why the term "culture-reduced" is more honest, and how IQ Octopus applies the idea.
Want your own number? The test is 25 visual puzzles, about 12 minutes, no sign-up.
The problem these tests try to solve
Many intelligence tests include tasks that depend on what you have learned: defining words, answering general knowledge questions, solving word problems. Those tasks are informative, but they also measure your language, your schooling and the culture you grew up in. Someone tested in their second language, or someone who had little formal education, can score lower for reasons that have nothing to do with how well they reason.
Psychologists describe this with a distinction Raymond Cattell made in 1963: fluid intelligence is reasoning with novel material, and crystallized intelligence is accumulated knowledge (Wikipedia: Fluid and crystallized intelligence). A culture-fair test tries to measure the fluid side as directly as possible, by giving everyone material that nobody has studied.
How culture-fair tests are built
The common ingredients are simple:
- abstract shapes, lines and dots rather than pictures of familiar objects;
- rules about position, count, rotation and pattern rather than about meaning;
- multiple-choice answers, so there is nothing to write;
- minimal instructions, often shown with an example rather than explained in words.
The best-known example is Raven's Progressive Matrices. John C. Raven developed them in the 1930s and they were first published in 1938. They are non-verbal matrix puzzles and are widely used as a measure of fluid, culture-reduced reasoning (Wikipedia: Raven's Progressive Matrices). Our guide to matrix reasoning explains how such puzzles work.
The Cattell Culture Fair tests follow the same idea. If you compare scores, note that the Cattell Culture Fair III scale uses a standard deviation of 24 rather than the usual 15 (Wikipedia: IQ classification). That is why Mensa UK lists a qualifying score of 148 on the Cattell III B, the same 98th percentile that is 132 on the Culture Fair test (Mensa UK).
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 1 is the original figure turned a quarter turn counterclockwise.
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 quarter turn counterclockwise gives option 1.
- 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.
Why “culture-reduced” is the honest term
Removing words removes one big source of bias, but not all of them. Culture shapes how people approach a test in quieter ways:
- Familiarity with the format. People who have done many puzzles, or many tests, know what to look for. Retaking cognitive tests raises scores by about a quarter of a standard deviation on average, roughly 4 IQ points (Hausknecht et al., 2007), which shows how much familiarity alone is worth.
- Schooling habits. Working carefully against a clock, checking answers and guessing well on multiple choice are habits that schooling builds, and schooling differs from place to place.
- Environment over time. Average measured IQ rose by about 2.8 points per decade across many countries in the 20th century (Pietschnig & Voracek, 2015). Changes that large, over a few generations, suggest that environment influences test performance.
- Screens and devices. On an online test, comfort with touchscreens and small images matters too.
That is why Raven's matrices are often described as culture-reduced rather than culture-free. The aim is to make the playing field as level as practical, not to claim it is perfectly level.
What culture-fair tests are good for
Nonverbal reasoning tests are useful whenever language would get in the way: people tested outside their first language, comparisons across groups with different schooling, and quick estimates of general reasoning ability. They are narrower than a full clinical battery, which samples many abilities, so they work best as one strong signal rather than the whole picture. The comparison of major IQ tests shows where they sit among the alternatives.
How IQ Octopus applies the idea
Every IQ Octopus puzzle is built to depend on reasoning rather than knowledge:
- No words in the puzzles. Patterns, grids, rotations and analogies use only geometric shapes. Section titles and short instructions are in English, but no answer depends on language.
- Color is never a rule. Puzzles are drawn in a single ink color, so color vision differences do not affect any answer.
- Generated, not memorized. Puzzles are generated fresh for each attempt, so having seen a particular puzzle before does not help.
- One honest exception. The Quantitative Reasoning section uses number series, which assume you can add, subtract and multiply. The arithmetic is simple, but it is learned.
You can see one example of each puzzle type on the practice page, and read the full method on how it works.
Sources
- Raven's Progressive Matrices. Wikipedia. en.wikipedia.org/wiki/Raven%27s_Progressive_Matrices
- Fluid and crystallized intelligence. Wikipedia. en.wikipedia.org/wiki/Fluid_and_crystallized_intelligence
- IQ classification. Wikipedia. en.wikipedia.org/wiki/IQ_classification
- IQ tests. British Mensa. www.mensa.org.uk/iq-tests
- 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
- Pietschnig, J., & Voracek, M. (2015). One century of global IQ gains. Perspectives on Psychological Science, 10(3), 282-306. doi.org/10.1177/1745691615577701