Geniuses, Savants, and the Real Cases Behind Record IQ Scores
Every week, some post about "the highest IQ in history" makes the rounds online. A few have a real basis, with caveats. Others are legends repeated until nobody questions them. Here are the actual cases behind the myth, along with a method for doubting well the next time you see a spectacular number.
Marilyn vos Savant and the record Guinness retired
In 1986, the Guinness Book of World Records listed columnist Marilyn vos Savant with an IQ of 228, the highest ever recorded. The entry did exist, but there's fine print: Guinness dropped the category in 1990 because the tests behind that figure, taken when vos Savant was a child, aren't statistically comparable or reliable at that scale. Psychometricians today broadly agree that a "228" makes no mathematical sense on modern scales. With a standard deviation of 15, a 228 would sit more than eight standard deviations above the mean, a spot that on a normal curve would correspond to a frequency far lower than one person among everyone alive.
Kim Peek: extraordinary memory, modest IQ score
Kim Peek, the man who inspired the character in the film "Rain Man," could read two pages at once (one with each eye) and memorized the contents of thousands of books. Yet on standard IQ tests he scored relatively low, around 87. Peek had savant syndrome: an extraordinary and very specific ability, memory, that a general IQ test isn't built to capture, since it aims to measure broad reasoning rather than raw recall. The overall score averages several areas, so one towering ability can be offset by others that perform lower.
Do top chess players have sky-high IQs?
It's a widespread assumption, but the evidence is more modest than it sounds. Research on chess players, including the work of psychologist Merim Bilalić, finds a link between IQ and playing strength that is weaker than you'd expect. What best sets a grandmaster apart is thousands of hours of deliberate practice and pattern recognition trained specifically for chess: a highly specialized skill, not a general measure of intelligence.
William James Sidis and the IQ 250 legend
Sidis was a genuine child prodigy: he entered Harvard at 11. But the "IQ 250 or higher" figure attached to him, often cited as the highest in history, was never documented with a verifiable standardized test. Like the Einstein number, it became a legend through repetition, not evidence.
Why record numbers are so appealing
A big number is easy to share and needs no context, which is what makes it go viral. The honest explanation, by contrast, requires talking about scales, norms, and the limits of tests, and that rarely fits in a post. That's why inflated versions keep circulating and corrections reach fewer people than the original claim.
The pattern holds across all four cases: the most spectacular IQ numbers online almost never come from a real, verifiable test. The real data may be less viral, but it's usually more interesting.
Next time you run into a number like that, ask yourself three things:
- Which specific test was used, and is there a verifiable record that this person took it?
- Who administered it, at what age, and in what year?
- What scale was the result expressed on, and is it comparable with today's?
If there's no clear answer to all three, the sensible move is to treat the figure as an anecdote.
If you'd rather find out for yourself, take the test on this site: timed, with questions that get harder, and no inflated numbers.
