IQ and Magnus Carlsen, Leo Messi and the Decathlon

by ragintumbleweed10 min read28th Mar 201729 comments

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IQ and g-factor
Personal Blog

[Epistemic Status: I suspect that this is at least partially wrong. But I don’t know why yet, and so I figured I’d write it up and let people tell me. First post on Less Wrong, for what that’s worth.] 

First thesis: IQ is more akin to a composite measure of performance such as the decathlon than it is to a single characteristic such as height or speed.

Second thesis: When looking at extraordinary performance in any specific field, IQ will usually be highly correlated with success, but it will not fully explain or predict top-end performance, because extraordinary performance in a specific field is a result of extraordinary talent in a sub-category of intelligence (or even a sub-category of a sub-category), rather than truly top-end achievement in the composite metric.                                         

Before we go too far, here are some of the things I’m not arguing:

  • IQ is largely immutable (though perhaps not totally immutable).
  • IQ is a heritable, polygenic trait.
  • IQ is highly correlated with a variety of achievement measures, including academic performance, longevity, wealth, happiness, and health.
  • That parenting and schooling matter far less than IQ in predicting performance.
  • That IQ matters more than “grit” and “mindset” when explaining performance.
  • Most extraordinary performers, from billionaire tech founders to chess prodigies, to writers and artists and musicians, will possess well-above-average IQ.[1]

Here is one area why I’m certain I’m in the minority:

Here is the issue where I’m not sure if my opinion is controversial, and thus why I’m writing to get feedback:

  • While IQ is almost certainly highly correlated with high-end performance, IQ fails a metric to explain or, more importantly, to predict top-end individual performance (the Second Thesis).

Why IQ Isn’t Like Height

Height is a single, measurable characteristic. Speed over any distance is a single, measurable characteristic. Ability to bench-press is a single, measurable characteristic.

But intelligence is more like the concept of athleticism than it is the concept of height, speed, or the ability to bench-press.  

Here is an excerpt from the Slate Star Codex article Talents part 2, Attitude vs. Altitude:

The average eminent theoretical physicist has an IQ of 150-160. The average NBA player has a height of 6’ 7”. Both of these are a little over three standard deviations above their respective mean. Since z-scores are magic and let us compare unlike domains, we conclude that eminent theoretical physicists are about as smart as pro basketball players are tall.

Any time people talk about intelligence, height is a natural sanity check. It’s another strongly heritable polygenic trait which is nevertheless susceptible to environmental influences, and which varies in a normal distribution across the population – but which has yet to accrete the same kind of cloud of confusion around it that IQ has.

All of this is certainly true. But here’s what I’d like to discuss more in depth:

Height is a trait that can be measured in a single stroke. IQ has to be measured by multiple sub-tests.

IQ measures the following sub-components of intelligence:

  •  Verbal Intelligence
  • Mathematical Ability
  • Spatial Reasoning Skills
  • Visual/Perceptual Skills
  • Classification Skills
  • Logical Reasoning Skills
  • Pattern Recognition Skills[2]

Even though both height and intelligence are polygenic traits, there is a category difference between two.

That’s why I think that athleticism is a better polygenic-trait-comparator to intelligence than height. Obviously, people are born with different degrees of athletic talent. Athleticism can be affected by environmental factors (nutrition, lack of access to athletic facilities, etc.). Athleticism, like intelligence, because it is composed of different sub-variables (speed, agility, coordination – verbal intelligence, mathematical intelligence, spatial reasoning skills), can be measured in a variety of ways. You could measure athleticism with an athlete’s performance in the decathlon, or you could measure it with a series of other tests. Those results would be highly correlated, but not identical. And those results would probably be highly correlated with lots of seemingly unrelated but important physical outcomes.

Measure intelligence with an LSAT vs. IQ test vs. GRE vs. SAT vs. ACT vs. an IQ test from 1900 vs. 1950 vs. 2000 vs. the blink test, and the results will be highly correlated, but again, not identical.

Whether you measure height in centimeters or feet, however, the ranking of the people you measure will be identical no matter how you measure it.

To me, that distinction matters.

I think this athleticism/height distinction explains part (but not all) of the “cloud” surrounding IQ.[3]

Athletic Quotient (“AQ”)

Play along with me for a minute.

Imagine we created a single, composite metric to measure overall athletic ability. Let’s call it AQ, or Athletic Quotient. We could measure AQ just as we measure IQ, with 100 as the median score, and with two standard deviations above at 130 and four standard deviations above at 160.

For the sake of simplicity, let’s measure athletes’ athletic ability with the decathlon. This event is an imperfect test of speed, strength, jumping ability, and endurance.

An Olympic-caliber decathlete could compete at a near-professional level in most sports. But the best decathletes aren’t the people whom we think of when we think of the best athletes in the world. When we think of great athletes, we think of the top performers in one individual discipline, rather than the composite.

When people think of the best athlete in the world, they think of Leo Messi or Lebron James, not Ashton Eaton.

IQ and Genius

Here’s where my ideas might start to get controversial.

I don’t think most of the people we consider geniuses necessarily had otherworldly IQs. People with 200-plus IQs are like Olympic decathletes. They’re amazingly intelligent people who can thrive in any intellectual environment. They’re intellectual heavyweights without specific weaknesses. But those aren’t necessarily the superstars of the intellectual world. The Einsteins, Mozarts, Picassos, or the Magnus Carlsens of the world – they’re great because of domain-specific talent, rather than general intelligence. 

Phlogiston and Albert Einstein’s IQ

Check out this article.

The article declares, without evidence, that Einstein had an IQ of 205-225.

The thinking seems to go like this: Most eminent physicists have IQs of around 150-160. Albert Einstein created a paradigm shift in physics (or perhaps multiple such shifts). So he must have had an IQ around 205-225. We’ll just go ahead and retroactively apply that IQ to this man who’s been dead for 65 years and that’ll be great for supporting the idea that IQ and high-end field-specific performance are perfectly correlated.

As an explanation of intelligence, that’s no more helpful than phlogiston in chemistry.

But here’s the thing: It’s easy to ascribe super-high IQs retroactively to highly accomplished dead people, but I have never heard of IQ predicting an individual’s world-best achievement in a specific field. I have never read an article that says, “this kid has an IQ of 220; he’s nearly certain to create a paradigm-shift in physics in 20 years.” There are no Nate Silvers predicting individual achievement based on IQ. IQ does not predict Nobel Prize winners or Fields Medal winners or the next chess #1. A kid with a 220 IQ may get a Ph.D. at age 17 from CalTech, but that doesn’t mean he’s going to be the next Einstein.

Einstein was Einstein because he was an outsider. Because he was intransigent. Because he was creative. Because he was an iconoclast. Because he had the ability to focus. But there is no evidence that he had an IQ over 200. But according to the Isaacson biography at least, there were other pre-eminent physicists who were stronger at math than he was. Of course he was super smart. But there's no evidence he had a super-high IQ (as in, above 200).

We’ve been using IQ as a measure of intelligence for over 100 years and it has never predicted an Einstein, a Musk, or a Carlsen.[4] Who is the best counter-example to this argument? Terence Tao? Without obvious exception, those who have been recognized for early-age IQ are still better known for their achievements as prodigies than their achievements as adults.

Is it unfair to expect that predictive capacity from IQ? Early-age prediction of world-class achievement does happen. Barcelona went and scooped up Leo Messi from the hinterlands of Argentina at age 12 and he went and became Leo Messi. Lebron James was on the cover of Sports Illustrated when he was in high school.

In some fields, predicting world-best performance happens at an early age. But IQ – whatever its other merits – does not seem to serve as an effective mechanism for predicting world-best performance in specific individualized activities.

Magnus Carlsen’s IQ

When I type in Magnus Carlsen’s name into Google, the first thing that autofills (after chess) is “Magnus Carlsen IQ.”

People seem to want to believe that his IQ score can explain why he is the Mozart of chess.  

We don’t know what his IQ is, but the instinct people have to try to explain his performance in terms of IQ feels very similar to people’s desire to ascribe an IQ of 225 to Einstein. It’s phlogiston.

Magnus Carlsen probably has a very high IQ. He obviously has well above-average intelligence. Maybe his IQ is 130, 150, or 170 (there's a website called ScoopWhoop that claims, without citation, that it's 190). But however high his IQ, doubtless there are many or at least a few chess players in the world who have higher IQs than he has. But he’s the #1 chess player in the world – not his competitors with higher IQs. And I don’t think the explanation for why he’s so great is his “mindset” or “grit” or anything like that.

It’s because IQ is akin to an intellectual decathlon, whereas chess is a single-event competition. If we dug deep into the sub-components of Carlsen’s IQ (or perhaps the sub-components of the sub-components), we’d probably find some sub-component where he measured off the charts. I’m not saying there’s a “chess gene,” but I suspect that there is a trait that could be measured as a sub-component of intelligence that that is more specific than IQ that would be a greater explanatory variable of his abilities than raw IQ.

Leo Messi isn’t the greatest soccer player in the world because he’s the best overall athlete in the world. He’s the best soccer player in the world because of his agility and quickness in incredibly tight spaces. Because of his amazing coordination in his lower extremities. Because of his ability to change direction with the ball before defenders have time to react. These are all natural talents. But they are only particularly valuable because of the arbitrary constraints in soccer.

Leo Messi is a great natural athlete. If we had a measure of AQ, he’d probably be in the 98th or 99th percentile. But that doesn’t begin to explain his otherworldly soccer-playing talents. He probably could have been a passable high-school point guard at a school of 1000 students.  He would have been a well-above-average decathlete (though I doubt he could throw the shot put worth a damn).

But it’s the unique athletic gifts that are particularly well suited to soccer that enabled him to be the best in the world at soccer. So, too, with Magnus Carlsen with chess, Elon Musk with entrepreneurialism, and Albert Einstein with paradigm-shifting physics.

The decathlon won’t predict the next Leo Messi or the next Lebron James. And IQ won’t predict the next Magnus Carlsen, Elon Musk, Picasso, Mozart, or Albert Einstein.

And so we shouldn’t seek it out as an after-the-fact explanation for their success, either.


[1] Of course, high performance in some fields is probably more closely correlated with IQ than others: physics professor > english professor > tech founder > lawyer > actor > bassist in grunge band. [Note: this footnote is total unfounded speculation]

[2] http://www.iqtestexperts.com/iq-test-parts.php

[3] The other part is that people don’t like to be defined by traits that they feel they cannot change or improve.

[4] Let me know if I am missing any famous examples here.

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29 comments, sorted by Highlighting new comments since Today at 3:45 AM
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First thesis: IQ is more akin to a composite measure of performance such as the decathlon than it is to a single characteristic such as height or speed.

Second thesis: When looking at extraordinary performance in any specific field, IQ will usually be highly correlated with success, but it will not fully explain or predict top-end performance, because extraordinary performance in a specific field is a result of extraordinary talent in a sub-category of intelligence (or even a sub-category of a sub-category), rather than truly top-end achievement in the composite metric.

I don't understand what you are trying to argue here; many of your claims seem to be dubious or wrong, and in particular, you seem to be covertly redefining and using in non-statistical ways words like 'predict' which have accepted statistical meanings, especially around here. IQ is not going to correlate r=1 with any measure of success because no measure of success is identical with intelligence. The existence of successful scientists or chess players whose rank-percentile in IQ is less than their rank-percentile in scientific accomplishment or chess playing does not shed any light on what the neurological basis of IQ, as this is a general phenomenon of regression to the mean and the extreme order statistics of two variables which are correlated r<1: http://lesswrong.com/lw/km6/why_the_tails_come_apart/ I'm not sure how this is relevant to any discussions of what neurological features IQ is caused by or what the causal nature of IQ is - but looking at the extremes doesn't tell us anything I can think of. Consider two traits X and Y which are correlated r<1, 0.99 say; in world A, you measure 100 people, and in world B (with the same X and Y and all causal aspects the same), you measure 1 billion people, and you note that the person ranked #1 for X is not ranked #1 for y, and in world B, the #1 X guy is in fact hundreds of thousands or millions of spots down the list of Yers; what have you learned about world B which is different from world A? Nothing, as far as I can see.

Or take the example of height. You know it's heritable, polygenic, due to greater size in all parts of the body, affected by primarily generalist genes (as well as variants with body-part-limited effects), and the various environmental & genetic effects generally have overall effects due to affecting metabolism & nutritional resources etc, and so it is a very real factor; but the best pro basketball player is not the tallest pro basketball player - does this show that height is somehow not real or not a general body size factor? If points scored in the NBA correlated r=0.90 with height, would this show that height is actually caused by a bunch of independent genes, and r=0.99 would show it's really a latent factor? How is there any connection here between points scored in the NBA championship and what height 'really' is, surely the correlation is going to be entirely driven by, you know, how useful height is playing basketball compared to other things like musculature or aerobic endurance?

Whether you measure height in centimeters or feet, however, the ranking of the people you measure will be identical no matter how you measure it.

No, it won't; it will depend on how you measure it and when and where and by whom, just like a LSAT will be highly correlated with but not identical with an IQ test. There is measurement error in measurements of height, reflecting issues of the person taking the measurement, how the measured person stands, what time of day it is, what shoes they are wearing, what phase of life they are in, whether they just came back from the International Space Station, whether you are using self-reports or doctor measurements, and so on. Many objective measurements, from blood panels to brain volume, have measurement error in them; every morning I weigh myself 3 times on my bathroom scale and record the data, and you know what, maybe once a month all 3 weighings will agree exactly on my current weight/BMI/body-fat-percentage/resting-metabolism/visceral-fat, and the rest of the time they'll disagree, sometimes by half a kilogram. My weight and body fat percentage hadn't changed in the 30 seconds it takes, but nevertheless. Everything has measurement error in it. Some things are easier to measure, is all.

We’ve been using IQ as a measure of intelligence for over 100 years and it has never predicted an Einstein, a Musk, or a Carlsen.[4] Who is the best counter-example to this argument? Terence Tao? Without obvious exception, those who have been recognized for early-age IQ are still better known for their achievements as prodigies than their achievements as adults.

Of course IQ scores predicted them, or would have. Even if you take the bogus examples people like to cite like Feynman, the IQ scores are still well >100. Every IQ study shows predictive power. The Terman study famously just missed some future Nobelists because Terman could only follow a small number of kids. Note that early-age IQ is not the same as adult IQ (any more than childhood height is identical to adult height!), so it's not even the same thing in the first place (which is probably one reason that, for example, Hunter Elementary School has disappointed its administration - after all, after regression to the mean of their stable adult IQ, the students are not that special). Or, forget Roe or TIP or SMPY, just think about university admissions standards! No one gets into MIT, Stanford, Harvard, or Yale (much less their grad programs) with a 1000 SAT and a 3.0 GPA. Surely you admit at least one important person who wasn't Terence Tao graduated from a college like Oxford or CMU and had high SAT scores, which you note correlates highly with IQ?

First of all, I very much enjoy your blog and writing in general. So thank you for commenting.

The existence of successful scientists or chess players whose rank-percentile in IQ is less than their rank-percentile in >scientific accomplishment or chess playing does not shed any light on what the neurological basis of IQ, as this is a general >phenomenon of regression to the mean and the extreme order statistics of two variables which are correlated rhttp://lesswrong.com/lw/km6/why_the_tails_come_apart/ I'm not sure how this is relevant to any discussions of what >neurological features IQ is caused by or what the causal nature of IQ is - but looking at the extremes doesn't tell us >anything I can think of.

I had not seen this before. I appreciate that this piece does a better job of explaining (at least part of) what I was trying to get at in my second thesis than I did in my original post.

I think what what Thrasymachus articulates well is that is that when we are looking to explain stratospheric performance in any given field, other factors matter more than raw IQ.

No, it won't; it will depend on how you measure it and when and where and by whom, just like a LSAT will be highly >correlated with but not identical with an IQ test.

Ok - everything has measurement error in it. But the degree of variation when measuring intelligence is far greater than when measuring height. Perhaps that's because it's merely harder to measure, but it might also be attributable to differences in what's being measured.

I'm not saying that intelligence isn't real any more than I was suggesting that athleticism isn't real. Just that they are best understood as composite measures.

I think what what Thrasymachus articulates well is that is that when we are looking to explain stratospheric performance in any given field, other factors matter more than raw IQ.

I don't think that's true, in either the statistical sense or the causal sense. If you take a pair of variables which are correlated r>=0.25, you have, pretty much by definition, found that one variable 'matters' more than any other single variable can, simply because it has explained/predicted the majority of the variance (sqrt(0.25)=0.5). Another variable can't explain more of the variance. At most, it can add some incremental predictive value. Given the various results like Roe's profiles or TIP/SMPY's statistics on doctorates & research publications, I am very comfortable asserting that if you took an entire population and you correlated IQ with research output or eminence in any intellectual field, either as a continuous or dichotomous outcome variable, you will find that the IQ scores alone will explain most of the variance, and it will, on its own, outpredict alternative variables like family SES. And, given adoption studies, iodine studies and so on, I am comfortable further asserting that this reflects a direct causal impact of intelligence itself on intellectual eminence (and IQ here is not merely a statistical correlation which happens to be excellently predictive because it's confounded with family SES or something).

If you have engaged in range restriction by looking at the correlation of the small IQ differences between grad students and future success, then yes, it will explain a lot less variance. But only because you have already pre-selected extremes of the population.

Of course, since IQ is relatively easy to measure via SATs and grades (look at how easy TIP/SMPY were to do - picking out future movers and shakers from millions of kids using just a cut-down SAT - please appreciate how astounding it is that you can just administer a short pencil-and-paper test to millions of kids and taking the top thousand or so, get such an incredible enrichment, with huge odds ratios for accomplishment), it is easy to create these selected extremes, and so we have a pleasant problem: even having boiled down the general population into a concentrated residue of likely to succeed people, there is some variance remaining as not all of them will succeed; so why do some succeed and others fail? This is certainly an interesting and useful question to ask, and I would refer you to Murray's Human Accomplishment and especially Simonton's entire body of work and discussion of additional incrementally-predictive variables like the Openness/Conscientiousness personality factors, some of which I discuss in http://lesswrong.com/lw/9m6/the_personality_of_greatcreative_scientists_open/

But nevertheless. Openness and Conscientiousness do not outpredict IQ, and are not causally more important for accomplishment. If one is considering something like iodization or embryo selection, one ought to keep this in mind and not be misled by range restriction or conditioning. Similarly, height may not be all that predictive within the NBA, but in general, it certainly is real, a general factor which is not a 'composite measure', and highly correlated with and causal of basketball success.

If you take a pair of variables which are correlated r>=0.25, you have, pretty much by definition, found that one >variable 'matters' more than any other single variable can, simply because it has explained/predicted the majority of >the variance (sqrt(0.25)=0.5). Another variable can't explain more of the variance.

I agree that g is probably more predictive of success than any other single variable. Cumulatively, other factors may matter more. But it is likely true that no one factor matters more. But I think that debate is tangential to the original post.

The original post had two points.

The “first thesis” was to argue that intelligence is more like athleticism than height.

The “second thesis” was to focus on the sub-components of intelligence as better predictors of domain-specific high-level success than the general factor.

I have not been dissuaded on either thesis.

The more I read about this, the more I believe that both of these theses are supported by CHC theory, which, according to a 2005 paper by Alfonso, Flanagan, and Radwan, is, “the most comprehensive and empirically supported psychometric theory of the structure of cognitive and academic abilities to date.” (Thanks, 9eB1!) The paper goes on to say:

Others, however, believe that g is the most important ability to assess because it predicts the lion’s share of the >variance in multiple outcomes, both academic and occupational (e.g., Glutting, Watkins, & Youngstrom, 2003). >Notwithstanding one’s position on the importance of g in understanding various outcomes (particularly academic), >there is considerable evidence that both broad and narrow CHC cognitive abilities explain a significant portion of >variance in specific academic abilities, over and above the variance accounted for by g (e.g., McGrew, Flanagan, >Keith, & Vanderwood, 1997; Vanderwood, McGrew, Flanagan, & Keith, 2002).

I’m not sure whether you would disagree with the last sentence of that paragraph, but that’s really what I was trying to get at with thesis 2.

With thesis 1, I think CHC theory provides further support for my belief that athleticism is a much better analogy for intelligence than a simple variable such as height. According to the paper, “CHC theory currently consists of 10 broad cognitive abilities and more than 70 narrow abilities.” These are all subsumed in two strata below the general factor.

To me, it would be very easy to imagine breaking down athleticism into 10 general categories and 70 narrow abilities as well. I think by breaking down athleticism into those subcategories, you could explain a significant portion of variance in specific athletic outcomes, over and above the variance accounted for by athleticism generally.

But how could you possibly break down height into 10 general categories and 70 narrow abilities? Trying to break down height into 70 sub-categories would be equal parts useless and meaningless. What could you explain or predict by breaking down height into 70 subcategories?

I think the answer is nothing.

Of course, since IQ is relatively easy to measure via SATs and grades (look at how easy TIP/SMPY were to do - >picking out future movers and shakers from millions of kids using just a cut-down SAT - please appreciate how >astounding it is that you can just administer a short pencil-and-paper test to millions of kids and taking the top >thousand or so, get such an incredible enrichment, with huge odds ratios for accomplishment), it is easy to create >these selected extremes, and so we have a pleasant problem:

I don’t disagree with any of this.

Openness and Conscientiousness do not outpredict IQ, and are not causally more important for accomplishment.

I’m not arguing that, either.

What I am arguing, is that by breaking down intelligence into various subcategories, researchers are better able to predict who will do well at what specific tasks. That the breakdown of the subcategories of Carlsen’s intelligence would likely provide much better insight into his abilities than his raw IQ.

Since we’re all NBA fans here, I’ll continue working with that theme. If you look at any given player in the NBA, it’s obvious why they are there. 5’11” Allen Iverson had one in a billion-ish speed and agility. Yao Ming had one in a billion-ish height and coordination. Lebron James has a one in 10 billion-ish combination of strength, speed, size, and coordination (there may never have been anyone in human history with his combination of those talents). They’re all Hall of Famers or will be eventually. They’re all genetic freaks. But they are very different kinds of genetic freaks.

Just as the sub-categories of athleticism will predict whether someone will be better suited to point guard or center, so, too, will sub-categories of intelligence better explain whether someone will be better suited English literature or chess. And that sub-categories may even be capable of predicting prodigies, savants, and geniuses in given fields.

As we break down the top tiny fraction of 1% of the population, those nuances in what constitutes their sub-categories athleticism and intelligence are what makes them interesting and likely to accomplish extraordinary things at any given task.

Ultimately, I would guess that further exploration of the sub-categories of intelligence are likely to reveal much more about Einsteins, Musks, Carlsens, and Mozarts. And that improved understanding and modeling of the sub-categories will eventually enable us to have a much better understand about what makes them who they are -- and perhaps predict future versions of them. But I think it will be the more nuanced understanding of these sub-categories, not further emphasis on the general factor, that will enhance this understanding.

From the same Alfonso paper:

Future research will probably continue to examine the importance of specific cognitive abilities in the explanation of academic outcomes, above and beyond the variance explained by g. Also, it is hoped >that future research in the field of learning disabilities will be guided by CHC theory, and that the search for aptitude–achievement interactions will be revisited using CHC constructs as opposed to Wechsler’s traditional clinical composites (i.e., Verbal and Performance IQs)

(emphasis added)

But I think that debate is tangential to the original post.

I don't think it is. You spend all this time hammering on how 'the top performer X in field Y doesn't have the top IQ', yet, this is exactly what you would expect for even a causal variable of unimpeachable status which causes the majority, or even almost every last bit of variance, in X performance. You seem to think it's extremely important, and tells us something very important about the nature of IQ, yet, I'm pretty sure it doesn't. Why you discuss it so much if it is so 'tangential'?

The “second thesis” was to focus on the sub-components of intelligence as better predictors of domain-specific high-level success than the general factor..> .. I’m not sure whether you would disagree with the last sentence of that paragraph, but that’s really what I was trying to get at with thesis 2.

But they're not! This is exactly what I was talking about! Yes, additional incremental variance after explaining g - but less variance. They're not "better".

But how could you possibly break down height into 10 general categories and 70 narrow abilities?

Certainly. As I said, height is mostly generalist genes, but there are also specific variants for parts of the body. Haven't you ever noticed how some families have different body proportions, with different leg:arm ratios, or longer necks, etc? You absolutely can measure arm length, head volume, leg length etc in all sorts of anatomic detail and (if anyone wanted to waste money on doing the measurements) do a GWAS on height and then specific body parts. You can also measure genetic correlations between body part sizes; for an example, look at Black 1982 https://en.wikipedia.org/wiki/Genetic_correlation#Anthropometric That height can be broken down into both the general height and narrower variables shouldn't be too surprising; consider Marfan syndrome.

What could you explain or predict by breaking down height into 70 subcategories?

Well, you could predict each individual measurement better from genes. Obviously. As for explanations, that will depend on the ingenuity of embryologists and endocrinologists and anatomists in nailing down the biological pathways from genetic variants to greater or less growth of forearms etc.

What I am arguing, is that by breaking down intelligence into various subcategories, researchers are better able to predict who will do well at what specific tasks. That the breakdown of the subcategories of Carlsen’s intelligence would likely provide much better insight into his abilities than his raw IQ.

Sure. No one is going to object to the claim that 'after you explain the majority of the variance in performance by the general factor, you can get additional incremental variance explained by focusing on narrower factors which weight more heavily on that particular field'. SMPY has demonstrated that very nicely by showing that verbal scores are overweighted for STEM achievement and one should emphasize more spatial/mathematical questions. But then you go and again claim that they are better predictors, which is either probably wrong or meaningless (wrong, if you mean they should be used in place of general intelligence, or meaningless, if you are referring to using them in addition to general intelligence). As I said, I feel like you are constantly moving the goalposts and redefining your terms in the OP and your comments and I'm having a hard time figuring out what you are really arguing.

Ultimately, I would guess that further exploration of the sub-categories of intelligence are likely to reveal much more about Einsteins, Musks, Carlsens, and Mozarts. And that improved understanding and modeling of the sub-categories will eventually enable us to have a much better understand about what makes them who they are -- and perhaps predict future versions of them. But I think it will be the more nuanced understanding of these sub-categories, not further emphasis on the general factor, that will enhance this understanding.

Possible but I think this over-rates how much we understand about general intelligence. I would argue that general intelligence is far more important to understand and increase if we want to understand or create more Einsteins. What is more valuable, some better testing to guide highly intelligent people (<1% of the population) into subfields using tailored tests and maybe increase their lifetime productivity 10%, or understand general intelligence somewhat better via GWASes, and get genetic engineering to increase population mean IQ by 5 points and increasing the fraction passing that cutoff by 500%? Considered as a leaky pipeline, optimizing the general population case is more effective than tweaking the few elites. (This is similar to something I found in my embryo selection analysis: even great interventions against rare diseases aren't very cost-effective compared to tiny interventions for intelligence or height, because the very rarity neutralizes the greatest and makes the absolute benefit small.)

I have not been dissuaded on either thesis.

I'm not sure either thesis is very controversial.

I'm not sure either thesis is very controversial.

As stated, yes, but once you get to "70 narrow abilities" of intelligence, my bullshit-o-meter starts to make excited noises... Though I haven't looked at the paper, so maybe it's excited for no good reason.

I agree, but unless I've misunderstood ragintumbleweed is citing CHC theory (the thing with the 70 narrow abilities) not as their main thesis but just to say "see, here's some mainstream academic work on this stuff, and it fits well with my account!". If it turns out that the 70 narrow abilities are entirely the product of fitting models to noise, or even that CHC theory as a whole is bullshit, that doesn't make much difference to the claims ragintumbleweed has actually made.

While IQ is almost certainly highly correlated with high-end performance, IQ fails a metric to explain or, more importantly, to predict top-end individual performance

Not controversial at all; seems like a straightforward application of the law of diminishing returns. If performance in a certain area depends partially on IQ and partially on some other X, then IQ will correlate with performance, but mere high IQ will not be enough to achieve best performance, because when you already have the high IQ, the amount of X becomes the critical factor.

IQ has to be measured by multiple sub-tests.

Wrong. For example, Raven's Progressive Matrices only have one category.

Phlogiston and Albert Einstein’s IQ

I agree that trying to indirectly calculate IQ of famous dead people is complete bullshit. Talking about values of IQ above 150 doesn't make sense statistically. Anything using Eistein as an example is automatically suspicious. And "he must have had high IQ, because he was awesome, and we believe high IQ is what makes people awesome" is circular logic.

But we should distinguish between the following statements...
1) People love to make stupid claims about IQ.
2) The concept of IQ is stupid.
...and a good start would be to look at what scientists are saying about IQ, as opposed to what clickbait journals do.

Wrong. For example, Raven's Progressive Matrices only have one category.

Ok. Fair point. But nearly all intelligence tests use a variety sub-tests. And I think the consensus among psychometricians is that more tests provide a better measure of intelligence.

My point isn't that IQ is stupid. My goal is to explore its boundaries and limitations.

If you want to explore the concept of IQ seriously, you should find out what people who study that concept seriously are saying. Here are the sources you used in the article:

  • an article in Business Insider, declaring without evidence that Einstein had an IQ of 205-225;
  • the first google result for "Magnus Carlsen IQ";
  • a made-for-adsense website called "IQ test experts" that provides a free "IQ test" to fish for e-mails.

Would you feel equally qualified to propose your new theory of e.g. quantum physics after doing a similar kind of research?

I suppose that's a fair criticism. But you have cherry picked these examples. In my defense, I also reference SSC and a 448-page book by Stephen Jay Gould on IQ, which is entirely about the history of psychometrics.

It's an area of interest, not necessarily an area of expertise. I wrote a post to get feedback and improve my understanding of the topic. I have a richer understanding of the issue than I had two days ago. And so I accomplished what I aspired to do.

book by Stephen Jay Gould on IQ

Uhm...

You might be interested in this paper on profoundly gifted children which says in part "different patterns of profound intellectual talent uncovered in their youth were predictive of qualitatively different educational, occupational, and creative outcomes"

"Figure 2 provides a basis for anticipating the unique value spatial ability might contribute to understanding intellectually talented youth. In the late 1970s, because of his interest in identifying and developing scientific talent—and knowing that by utilizing exclusively a general ability measure, Terman assessed and missed two Nobel Laurates (viz., Luis Alvarez and William Shockley, see Shurkin, 1992) Stanley gave a group of 563 SMPY participants tests of spatial ability designed for high school seniors."

"Clearly, the creative outcomes under analysis are supported by different configurations of intellectual talent. For example, among participants who secure patents, their spatial ability is commensurate with those who publish in STEM, but the latter are more impressive in mathematical and verbal reasoning. Participants who publish in Art–Humanities–Law–Social Sciences are the lowest in spatial ability of all four groups. This graph is psychologically informative, depicting the intellectual design space of creative thought."

I think this really hits at the main purpose of what I wrote -- that by over-emphasizing general intelligence, we may be missing opportunities to find more domain-specific talent indicators. Of course more general ability matters. But more specific ability applied to the right field probably matters even more.

So you point was that we don't make the mistake of evaluating or thinking basketball skills are all a direct relationship with a simple metric as height but that's what everyone is doing with IQ?

scooped up Leo Messi from the hinterlands of Argentina at age 12 and he went and became Leo Messi. Lebron James was on the cover of Sports Illustrated when he was in high school.

Identifying Messi at age 12 is a lot more impressive than identifying James a year before he goes pro, when the only thing holding him back from going pro immediately is the NBA's diploma requirement.

Some people say that Newton was "scooped up" at 12, although I'm not sure how accurate that is.

Even if it were true about Newton, it wouldn't be useful to compare him to Messi without knowing the base rate of how many kids are scooped up, in both fields. Here is something where we can look up the base rate: the IMO. Something like half of Fields Medalists won a gold medal at the IMO in high school. About 50 gold medals are handed out each year, fewer in the past. You should be really impressed by that rate of prediction. Of course, it's comparing math to math, not g.

Maybe a good comparison to IMO:Fields would be (First round draft pick):(Hall of Fame).

The tallest player to ever play in the NBA was Gheorghe Mureșan, who was 7'7". He was not very good. Manute Bol was almost as tall and he was good but not great. By contrast, the best basketball player of all time was 6'6" [citation needed]. In fact, perhaps an athletic quotient would be better for predicting top-end performance than height, since Jordon, Lebron and Kareem are all way more athletic than Muresan and Bol.

I will attempt to explain the strongest counterargument that I'm aware of regarding your first thesis. When you take a bunch of tests of mental ability and you create a correlation matrix, you obtain a positive manifold, where all the correlations are positive. When you perform a factor analysis of these subtests, you obtain a first factor that is very large, and secondary through n-iary factors that are small and vary depending on the number of factors you use. This is suggestive that there is some sort of single causal force that is responsible for the majority of test performance variation. If you performed a factor analysis of a bunch of plausible measures of athleticism, I think you would find that, for example, bench press and height do not participate in a positive manifold and you would likely find multiple relevant, stable factors rather than 1 athletic quotient that accounts for >50% of the variation. Cardio ability and muscular strength are at odds, so that would be at least two plausible stable factors. This argument is on Wikipedia here#Factor_structure_of_cognitive_abilities). Personally, in light of the dramatic differences there are between the different parts of an IQ test battery, I find this fact surprising and underappreciated. Most people do not realize this, and the folk wisdom is that there are very clear different types of intelligence.

The second point I would make regarding your first thesis is that there are plenty of researchers who don't like g, and they have spent decades trying to come up with alternative breakdowns of intelligence into different categorizations that don't include a single factor. Those efforts were mostly fruitless, because every time they were tested, it turned out that all the tests individually correlated with g still. Many plausible combinations of "intelligences" received this treatment. Currently popular models do have subtypes of intelligence, but they are all viewed sharing g as an important top-level factor (e.g. CHC theory) rather than g simply being a happenstance correlation of multiple factors. In this case absence of evidence is evidence of absence (in light of the effort that has gone into trying to uncover such evidence).

To be honest, I very much doubt that actual IQ researchers would disagree with your second thesis. My argument would be that for most fields there is enough randomness that you would not expect the most intelligent person to also be the most lauded. Even Einstein had to have the luck to have the insights he did, and there were undoubtedly many people who were just as smart but had different circumstances that led to them not having those insights. Additionally, there is a thing called Spearman's law of diminishing returns, which is the theory that the higher your g is, the less correlated your subtype intelligences are with your g factor. That is, for people who have very high IQs, there is a ton more variation between your different aspects of intelligence than there is for people with very low IQs. This has been measured and is apparently true, and would seem to support your thesis. It is true that these two observations (the factor decomposition and Spearman's law) seem to be in tension, but hopefully one day someone will come through with an explanation for intelligence that neatly explains both of these things and lots more besides.

Unrelated to your two theses, I think the fact that IQ correlates with SO MANY things makes it interesting alone. IQ correlates with school performance, job performance, criminality, health, longevity, pure reaction speed, brain size, income, and almost everything else (it seems like) that people bother to try correlating it with. If IQ hadn't originally come from psychometric tests, people would probably simply call it your "favor with the gods factor" or something.

There are enough correlations that any time I read a social sciences paper with statistics on outcomes between people with different characteristics, I always wish they would have controlled for IQ (but they never do). This may seem silly, but I think there is definitely an argument that can be made that IQ is "prior to" most of the things people study. We already know that IQ can't be meaningfully changed. It's pretty much set by the time you are an adult, and we know of nothing besides iodine deficiency that has a meaningful impact on it in the context of a baseline person in modern society.

It's pretty much set by the time you are an adult, and we know of nothing besides iodine deficiency that has a meaningful impact on it in the context of a baseline person in modern society.

This is not really true, AFAICT. There are so many health conditions that result in recognizable cognitive impairment that I see no reason to assume that the "baseline person in modern society" is effectively maximizing her realized IQ. Even something as common as major depressive disorder can impact cognition in ways that will make people measurably less effective at work. And let's not forget more permanent things like eating too many lead flakes as a kid, which can still have an impact on the "baseline person" long after lead paint has fallen out of use.

You are correct, there are things that can negatively impact someone's IQ. With respect to maximizing, I think the fact that people have been trying for decades to find something that reliably increases IQ, and everything leads to a dead-end means that we are pretty close to what's achievable without revolutionary new technology. Maybe you aren't at 100% of what's achievable, but you're probably at 95% (and of course percentages don't really have any meaning here because there is no metric which grounds IQ in absolute terms).

The tallest player to ever play in the NBA was Gheorghe Mureșan, who was 7'7". He was not very good.

He wasn't? He average 15 pts and 10 rebounds (and 2 blocks) as a 24 year old in the NBA. He had injuries, but was effective for a time when healthy.

First of all, thank you, 9eB1. This is exactly the kind of a charitable, informed, and thoughtful response I was hoping for. I appreciate your feedback. Also, you clearly know more about psychometrics than I do, so I will tread carefully in response.

The tallest player to ever play in the NBA was Gheorghe Mureșan, who was 7'7". He was not very good. Manute Bol was >almost as tall and he was good but not great. By contrast, the best basketball player of all time was 6'6" [citation needed]. In >fact, perhaps an athletic quotient would be better for predicting top-end performance than height, since Jordon, Lebron and >Kareem are all way more athletic than Muresan and Bol.

Not sure this is true. The average great athlete is probably around average height. And there are only a few of those in the NBA.

That said, NBA teams are pretty savvy about breaking down the specific characteristics that lead to NBA success. Not just height, but speed, quickness, vertical leap, ability to jump up and down multiple times, wingspan, shooting ability at different distances. There is plenty of specificity in NBA talent analysis. Height matters, but other factors matter, too. And those factors can and have been quantified.

Cardio ability and muscular strength are at odds, so that would be at least two plausible stable factors. This argument is on >Wikipedia here. Personally, in light of the dramatic differences there are between the different parts of an IQ test battery, I >find this fact surprising and underappreciated. Most people do not realize this, and the folk wisdom is that there are very >clear different types of intelligence.

Based on my quick research, I'm not sure that it is true that cardio and muscular strength are at odds.

I agree that IQ is plenty interesting by itself. My goal with this article was to explore the boundaries of that usefulness and explore the ways in which the correlations break down. And your feedback helps me a get a better sense of where those areas are.

To be honest, I very much doubt that actual IQ researchers would disagree with your second thesis. My argument would be >that for most fields there is enough randomness that you would not expect the most intelligent person to also be the most >lauded. Even Einstein had to have the luck to have the insights he did, and there were undoubtedly many people who were >just as smart but had different circumstances that led to them not having those insights.

I agree that luck plays a huge role in Einstein being Einstein. But I also think that to achieve the top levels of success at any specific endeavor, other factors besides IQ matter a lot, too. Hard work, intransigence, contrarianism -- these personality characteristics were probably determinative in him becoming who he was.

That said, NBA teams are pretty savvy about breaking down the specific characteristics that lead to NBA success. Not just height, but speed, quickness, vertical leap, ability to jump up and down multiple times, wingspan, shooting ability at different distances. There is plenty of specificity in NBA talent analysis. Height matters, but other factors matter, too. And those factors can and have been quantified.

I think basketball players are mainly judged on playing basketball, not wingspan, etc. Gheorghe Mureșan and Manute Bol are interesting not because they are tall, but because they started playing basketball in their mid to late teens. At their various stages of recruitment, they were probably judged differently than their competitors. Their competitors were probably judged by success on the court, while they were probably judged more on basics like wingspan, because they were expected to progress more than other players.

Added: people selected for being tall will be taller than they are good at basketball, while people selected for good at basketball will be better than they are tall.

I agree that IQ is plenty interesting by itself. My goal with this article was to explore the boundaries of that usefulness and explore the ways in which the correlations break down.

The Big 5 personality traits have a correlation with some measures of success which is independent of IQ. For example, in this paper:

Consistent with the zero-order correlations, Conscientiousness was a significant positive predictor of GPA, even controlling for gender and SAT scores, and this finding replicated across all three samples. Thus, personality, in particular the Conscientiousness dimension, and SAT scores have independent effects on both high school and college grades. Indeed, in several cases, Conscientiousness was a slightly stronger predictor of GPA than were SAT scores.

Notably, the Openness factor is the factor that has the strongest correlation with IQ. I'm guessing Gwern has more stuff like this on his website, but if someone makes the claim that IQ is the only thing that matters to success in any given field, they are selling bridges.

When we think of great athletes, we think of the top performers in one individual discipline, rather than the composite.

When people think of the best athlete in the world, they think of Leo Messi or Lebron James, not Ashton Eaton.

I'm not sure it's very relevant to your point, but I think it's pretty weird to call soccer or basketball "one individual discipline." I thought you were going to point to something obviously narrower than the decathlon, like one of its components. Whereas, popular spectator sports seem to me to involve a lot more skills than the decathlon. At the very least they involve teamwork and a lot more perception, but I think that they involve a greater variety of physical skills. On the other hand, OJ Simpson was a world-class sprinter, not a decathlete.

Understood. I didn't articulate this well. My point was merely to say that soccer, basketball, and other sports have arbitrary and sport-specific constraints, whereas the decathlon was explicitly constructed to test a battery of physical abilities. And perhaps that the composite well-rounded athlete is usually less interesting than someone who is a freak in a specific discipline.

The favored approach is,unfortunately, rather tautoligical: IQ measures 'intelligence' so imperfections with real world correlations can be explained by the notion that real world tasks are diluted with factors that are irrelevant to what we want to call 'intelligence'. This is opposed to the highly viable, but painful, explanation that IQ tests just dont pick up on other factors that are critical to generative thinking. One of the most hoary ideas is that because of some positive manifold, predicting a common underlying feature, it must reflect 'intelligence'. Absurd and akin to saying that because height is positively correlated to performance in practically all sports, that height = athleticism (interestingly, height is about 80 percent genetic, like IQ). There is absolutely no reason to view intelligence rooted in a single factor, especially, in light of late developments in cognitive psychology with intuition/heuristic processes which mediate analytical thinking.

A suggestion: IQ might be better understood less like Height and more like "how high can you jump". Where for example, people can train to jump higher, people can practice IQ tests. People can wear fancy shoes and jump a lot, causing different jumping results. People can fail to jump high unless they are wearing certain shoes, and you can claim that certain aids are cheating. For example - he's only a great musician and not really good at anything else, therefore not really a high IQ.

While this isn't a great analogy, it's more fitting than "how tall".