Every celebrity IQ score you have read is made up
Search for almost any famous person plus the letters IQ and you will get a number. Confident, specific, often to the point: 155, 152, 160. Follow it back and the trail always ends the same way, which is to say it does not end anywhere at all.
There is no published, verifiable IQ score for Elon Musk. Or Mark Zuckerberg, or Barack Obama, or Jim Carrey, or Lisa Kudrow. Not a low one, not a high one. The scores do not exist.
Where the numbers come from
Some are pure invention: a figure typed into a listicle a decade ago, then quoted by the next listicle, which is then quoted by the next. After enough repetitions the number has citations, and every citation leads to another site with the same number and no source.
Some are back-calculated from something else entirely. An old SAT score, a chess rating, a university place, a fact about someone's childhood. There are conversion tables floating around that turn test scores into IQ estimates, and they are far shakier than the confidence with which they get applied, particularly across decades where the tests were rescored and the populations changed.
And some are simply attributed to the wrong person, or to a character they played.
A number repeated a thousand times is still not a measurement. It is a rumour with a decimal point.
Why nobody publishes their real one
An IQ assessment is a clinical instrument administered one-to-one by a qualified psychologist, and the result is health information. It is not something you would casually put in an interview, and no reputable psychologist would release a client's score.
So when a figure appears for a living person, the sourcing question answers itself. Either they said it themselves, in which case it is unverified self-report, or somebody made it up.
What the number would mean if it existed
Here is the part the listicles skip. An IQ score is not a quantity of intelligence. It is a position in a distribution: how far you sit from the average of the group the test was standardised on, measured in standard deviations, then rescaled so the average reads 100.
Everything follows from that. A score of 130 does not mean thirty units of something. It means two standard deviations above the mean, which is about the 98th percentile. And because the scale is defined by the population, the population matters: scores have drifted upward across the twentieth century by roughly three points a decade, which is why tests are periodically restandardised and why comparing a score from 1975 with one from today is not straightforward.
It also means a score without its scale is meaningless. Some tests use a standard deviation of 15, others 16, others 24. The same performance yields 132, 134 or 151 depending on which one you took, and the internet quotes all three as though they were the same claim.
The signs-of-high-intelligence genre
The other half of this search results page is lists: seven traits, ten signs, fifteen strange indicators. Most of the items on them are unmeasured, unfalsifiable or flattering by design, which is the actual product. "You overthink things" and "you talk to yourself" describe nearly everyone.
Some things do correlate with measured ability, modestly and on average: reading a lot, vocabulary size, working memory capacity, reaction time. Modestly and on average is doing a great deal of work in that sentence, and none of them identifies an individual. A correlation across thousands of people tells you almost nothing about the person in front of you.
What we do here instead
Our reasoning test reports a range rather than a number, and says on the result page that it cannot be converted into a percentile. That is not modesty, it is arithmetic: a percentile requires a normative sample, we have no normative sample, and a figure that looks like an IQ score invites exactly the conversion this article is about.
If you want to know how you do on twenty generated reasoning puzzles, that we can tell you. If you want a real IQ assessment, that is a psychologist and an appointment, and it is worth knowing that most people who want the number turn out to want something else that the number does not supply.
IQ questions people actually ask
Is a 120 IQ a high IQ?
On a standard scale with a mean of 100 and a standard deviation of 15, 120 sits around the 91st percentile: higher than roughly nine people in ten. It is comfortably above average and it is not rare. About one person in eleven scores at or above it.
What IQ is the top 1%?
Roughly 135 on a 15-point scale, or about 137 on a 16-point one. This is why the scale matters more than the number: the same performance produces different figures depending on which test was used, and people quote the figure without the scale.
Is a 300 IQ possible?
No. IQ is defined by where you fall in a distribution, not by an amount of intelligence you possess. Scores beyond about 160 already describe fewer people than any test has ever been standardised on, and past roughly 200 the number stops corresponding to anything measurable. A claimed 300 is not an extreme score, it is a category error.
Does IQ decline with age?
The components move in opposite directions. Processing speed and abstract reasoning drift down from early adulthood, while vocabulary and accumulated knowledge keep rising for decades. Because IQ scores are age-normed, a stable score can hide both changes happening at once.
What raises IQ the most?
Education has by far the best evidence: additional years of schooling reliably raise scores, with estimates commonly landing between one and five points per year. Commercial brain training does not transfer well, and improves the trained task far more than anything else.
How do I check my IQ level?
Properly, through a supervised test administered by a qualified psychologist. Online tests, including ours, are not that: they are unsupervised, unnormed, and cannot produce a percentile. They can tell you how you did on their own questions, which is a smaller but honest thing.