IQ test
Article
IQ test is a recurring concept in the Astral Codex Ten archive, appearing 2 times across 2 issues between March 20, 2024 and June 27, 2025. The archive places it in contexts such as “only the smartest people remember their IQ test scores”; “You can signal intelligence with an IQ test”. It most often appears alongside 10,000 hour rule, 2 Hour Learning, Inc, 2-hour Learning.
Metadata
- Category: Concepts
- Mention count: 2
- Issue count: 2
- First seen: March 20, 2024
- Last seen: June 27, 2025
Appears In
Related Pages
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- 10,000 hour rule (1 shared issues)
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- 2 Hour Learning, Inc (1 shared issues)
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- 2-hour Learning (1 shared issues)
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- ACT (1 shared issues)
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- Alex Amplifier (1 shared issues)
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- Alpha (1 shared issues)
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- Alpha Portal (1 shared issues)
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- Alpha Portal (1 shared issues)
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- Alpha Reads (1 shared issues)
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- Alpha School (1 shared issues)
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- Alpha Writes (1 shared issues)
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- AlphaReads (1 shared issues)
External Links
Source Context
Recovered passages from the original issue text. When the raw archive preserved outbound links inside the source passage, they are listed directly under the quote.
The average ClearerThinking user reported their IQ as 130. These are implausibly high. Only 1/200 people has an IQ of 138 or higher. 1/50 people have IQ 130, but the ClearerThinking survey used crowdworkers (eg Mechanical Turk) who should be totally average. Okay, fine, so people lie about their IQ (or foolishly trust fake Internet IQ tests). Big deal, right? But these don’t look like lies. Both surveys asked for SAT scores, which are known to correspond to IQ. The LessWrong average was 1446, corresponding to IQ 140. The ClearerThinking average was 1350, corresponding to IQ 134. People seem less likely to lie about their SATs, and least likely of all to optimize their lies for getting IQ/SAT correspondences right. And the Less Wrong survey asked people what test they based their estimates off of. Some people said fake Internet IQ tests. But other people named respected tests like the WAIS, WISC, and Stanford-Binet, or testing sessions by Mensa (yes, I know you all hate Mensa, but their IQ tests are considered pretty accurate). The subset of about 150 people who named unimpeachable tests had slightly higher IQ (average 140) than everyone else. Thanks to Spencer Greenberg of ClearerThinking, I think I’m finally starting to make progress in explaining what’s going on. Problem #1: The Biggest SAT → IQ Conversion Site Is Wrong Thanks to Sebastian Jensen for pointing this out! He writes: A search of ‘SAT to IQ’ on google results in being presented with the website ‘iqcomparisonsite.com’. This man has directly converted the SAT percentiles to IQ scores, which is not what should be done. Tests like the ACT and SAT correlate with IQ at about 0.8-0.85 [rca], [my analysis], [emil article], [scholarly article]. The general factor of academic achievement and IQ correlate at about 0.81-0.88 [psychometric test], [GCSE grades]. This discrepancy occurs because they measure different abilities - an IQ test will test many different abilities, while the SAT/ACT only tests verbal/mathematical ability. In addition, these percentiles are very outdated as the average SAT score has changed over time due to changes in the content of the test. Instead, the ideal way to do this is to take the percentiles from the current versions of the SAT and then convert those into z-scores and then regress those z-scores by the mean by the estimated regression coefficient. Using Sebastian’s updated tables, we find that the average Less Wrong IQ as predicted by SATs goes down from 140 → 132, and the ClearerThinking IQ goes down from 134 → 124. So people probably exaggerated their IQs somewhat, and unrelatedly we were using an SAT → IQ conversion that exaggerated IQs, and so the numbers falsely appeared to match. Okay! It’s a start! Interlude: The ClearerThinking IQ Test The ClearerThinking survey included a battery of cognitive tests of exactly the sort that could usually be used to determine IQ. Unfortunately none of them were normed, so we know how all the 3700 subjects did relative to each other, but not where the 100 point is. Spencer was able to norm them to the general population based on education level. That is, he asked his sample about their educational attainment (college degree, PhD, etc) and found they were a little more educated than the US average. Since the US average IQ is 100, his sample should have an average a little higher than this. He was able to calculate how much higher. Then he mapped a bell curve to everyone in his sample’s performance on his tests. Since he had 3700 people, he was able to do this relatively smoothly. He found an average IQ of 110, which originally surprised me, because I thought his sample was supposed to be random crowdworkers, who should be close to the US average of 100. But in fact, his survey was a combination of 1900 crowdworkers and 1800 people who saw it on social media - eg friends and friends-of-friends of Spencer. Separating this out by group, we find that the crowdworkers have an average normed-IQ of 100, and the social media referrals have an average normed-IQ of 120, making the overall average of 110. This seems pretty trustworthy, since it correctly estimates the crowdworkers (completely average) as 100. Spencer studied math at Columbia, his friends and friends-of-friends are pretty smart, and I think the 120 estimate for them is also okay. But there’s still a problem here. Using an accurate SAT score → IQ calculator, we determined that the ClearerThinking average should be 124. But using real cognitive tests, it looks like it’s 110. What went wrong? Problem #2: Only The Smartest People Report Their SATs Using Spencer’s cognitive test results, we can compare people who did vs. didn’t take the SAT. We find: People who didn’t take the SAT (remember, this includes current high schoolers) have tested-IQ 110.
Inline links: corresponding to, for pointing this out!, [rca], [my analysis], [emil article], [scholarly article], [psychometric test], [GCSE grades], changed
People who took the SAT and do remember their score have tested-IQ 116. Either smarter people are more likely to remember their SAT scores, or people who did well on the SAT are more likely to make a point of remembering! Since the only reported SAT scores come from people who remember them, this means that SAT scores overestimate the full-sample IQ, at least in this case. We previously had a gap between the 124 IQ from SAT conversion and the 110 observed IQ. This resolves about half of the gap, bringing it down to 124 predicted vs. 116 observed. Problem #3: Something Is Wrong With Self-Reported IQ Test Scores The ClearerThinking sample has a tested-IQ of 110. But the subset of people who report having taken a past IQ test say they got an average score of 131. What’s going on? It could either be that only the smartest people remember their IQ test scores (as with SATs), or that these people are lying/misremembering/deluded. Which is it? The tested-IQ of this subgroup who report their scores is 114. So although they are a little smarter than the overall sample, most of the difference seems to be coming from some kind of falsehood/delusion. But it’s a surprisingly well-behaved falsehood/delusion. Self-reported IQ test score correlates 0.54 with tested IQ. So people are getting their rank order mostly right, they’re just wrong about the specific number. It looks like up to about 140, self-reported IQ and normed IQ rise together, and then the relationship breaks down. Sure enough, looking at the subset of self-reported IQ scores below 140, the correlation with tested IQ rises to .6, and looking at the subset above 140, the correlation is nonsignificant at -0.02. I don’t want to assert that the breakpoint is exactly 140, but I do think the test stops working somewhere in the 130 - 140 range. But this can’t be the whole problem. Notice that people who reported getting scores around 100 on previous IQ tests overwhelmingly got scores less than 100 on this one. So are people just taking terrible Internet IQ tests that inflate their score about 20 points? The ClearerThinking sample didn’t ask people what IQ test they took, but the LessWrong sample did. It found approximately the same score from WAIS, WISC, Stanford-Binet, and Mensa - all of which were about 10 points above what you would predict from SAT scores. So I think there are two things going on: The main problem in the LessWrong sample, and the far right end of the ClearerThinking sample, is that even official IQ tests are gobbledygook over 135. Any numbers above this should be rounded down to 135, no matter how venerable the test involved.
It looks like up to about 140, self-reported IQ and normed IQ rise together, and then the relationship breaks down. Sure enough, looking at the subset of self-reported IQ scores below 140, the correlation with tested IQ rises to .6, and looking at the subset above 140, the correlation is nonsignificant at -0.02. I don’t want to assert that the breakpoint is exactly 140, but I do think the test stops working somewhere in the 130 - 140 range. But this can’t be the whole problem. Notice that people who reported getting scores around 100 on previous IQ tests overwhelmingly got scores less than 100 on this one. So are people just taking terrible Internet IQ tests that inflate their score about 20 points? The ClearerThinking sample didn’t ask people what IQ test they took, but the LessWrong sample did. It found approximately the same score from WAIS, WISC, Stanford-Binet, and Mensa - all of which were about 10 points above what you would predict from SAT scores. So I think there are two things going on: The main problem in the LessWrong sample, and the far right end of the ClearerThinking sample, is that even official IQ tests are gobbledygook over 135. Any numbers above this should be rounded down to 135, no matter how venerable the test involved.
The top performing kids are WAY ahead of the average and the lower tier kids. The kids at the top percentile achieve the median score of a graduating senior by the end of 3rd grade! And recall this is not an IQ test – this is a content test. The top 1% of 3rd graders have more content knowledge and comprehension than the median high school graduate.
Our students are conformists Many people are surprised that anyone would want to signal conformity. Don’t most people and employers value “innovative thinking”? Maybe, but not in their new hires. Elite employers generally want bright, diligent hires who will color inside the corporate lines for a few years before they start “thinking outside the box”. Most successful businesses are successful for a reason. They want new employees to enter and do what they are told to in order to understand their new business before they try to “do things differently” and change things. Caplan explains that the need to signal conformity is the hardest hurdle to disrupting education. You can signal intelligence with an IQ test, and you can signal conscientiousness with any sort of time consuming long term task (Caplan gives the example of collecting the largest ball of string in the world). But by definition, if you do anything different from the norm of going to an existing well known school, you are signalling non-conformity. Caplan himself homeschooled some of his kids, but only after he verified that homeschooling for high school wouldn’t hurt his kids chances of getting into good colleges. He was non-conformist, but only willing to act on the non-conformity if it wouldn’t be punished by the conformists. Most people are not even going to go as far as Caplan. Most people are very happy to be conformists. That conformity is one reason why humans surpassed chimps. We are really good at watching other high status members of our communities and copying their behavior. I believe that is a big part of why moving to a better neighborhood leads to better outcomes for kids – because both the kids and the parents take on the “better” lifestyles of that community. But it also means that getting people to switch from the existing school system to something like Alpha will be difficult. Once we, personally, got over the more pedestrian concerns about moving for a school, our next concern was whether our kids would even get into Alpha. We did not need to worry. Alpha does have a screening process. They won’t accept kids who are disruptive and can’t focus in front of a computer for 20 minutes at a time. But the bar is relatively low. And yet the school is still, after more than a decade in operation, under-capacity. When other elite schools have 20% or lower acceptance rates – and limited “entrance points” (i.e. get your kid in at kindergarten or you are likely out of luck), Alpha is taking almost everyone who applies and allows students to jump in at any point – even mid-year. That reality replaced our first concern with another: Do we want to join a club that will so easily accept us as a member? Both my wife and I came from a world where: Low acceptance rate ~= quality We had just assumed that if we believed Alpha was worth moving across the country for, the school would be oversubscribed with local families. But it’s not even close. The hardest schools to get into in Austin are places like St Stevens and St Andrews – veritable institutions more than 70 years old. Those are the schools that the rich, old money families who have been in Austin for generations want to send their kids to. And if that is where the elite are sending their kids, why wouldn’t you want your kids in the same place? We already know that peers matter and that education differences are marginal at best – why not just optimize for the best peers (where best means the most exclusive club)? St Stevens and St Andrews are the best socially acceptable options: not this new weird Alpha school that uses AI to teach kids. Who would do that to their kids? What is the Alpha Target Audience? So who is going to Alpha? Mostly elite non-conformists. I think that broader group breaks down into three sub-segments (to use Marketing persona jargon): David Disruptor: Tech employee who has moved from the Bay area to Austin. He was nonconformist to even get into tech, and even more non-conformist to leave California