The article that you link shows a researcher supporting single digit percentage heritability doesn't actually show what you claim it shows. The article says that a polygenic score for patients with neuroimaging data (with only 27k samples) explained 7.6% of the variance in g.
PGS variance explained != heritability! That's like reporting benchmark results for your machine learning model before its finished training.
The low IQ heritability estimates you do find in the literature such as https://pmc.ncbi.nlm.nih.gov/articles/PMC6411041/ all seem to have the same issue: they estimate SNP heritability based on UK Biobank's fluid intelligence test, but they fail to account for the fact that the test sucks! Gold standard IQ tests have a test-retest correlation of >0.9. UK Biobank's is short, so the test-retest correlation is 0.61. This is massively deflating estimates of SNP heritability, and thus broad sense heritability!
They calculate SNP heritability of 0.19-0.22 when actual SNP heritability (after adjusting for the crappy test) is about 0.3.
But that's just SNP heritability. A good portion of the variance in IQ comes from rare variants (population frequency <1%), and about 20% of it comes from non-linear effects that are going to be very hard to capture without much larger sample sizes.
I have yet to find a credible IQ heritability estimate that's lower than 0.5
The biggest thing I took away from my Instrument Development class in grad school was that an instument is only valid when used for it's intended purpose. The IQ test was originally created to classify French orphans with cognitive delays into categories that could be used to group their educational needs by the program supporting them. Taking IQ measurements outside of this context automatically makes them invalid; the context has changed and the instrument for deciding what an individual's IQ is is no longer applicable. Sure, we can acknowledge that defferent instruments have been designed and used over the years to try to quantify intelligence - we certainly aren't using the same test the French orphans were given- but we've completely shifted the purpose of IQ from grouping students with similar abilities to recieve education suited to them, to making IQ a predictive measure of mental ability and success! And how can a body of research be considered solid on such a shifting foundation?
False. A measurement can be valid for a variety of contexts, particularly when it's measuring something primary. Besides which mere correlation is sufficient for it to be predictively useful.
Thanks for publishing this article, it could not have done a better job at filling gaps in my understanding of the topic. Really shifted the way I think about things.
IQ is a good predictor of outcomes -- on aggregate, and the larger the sample, the more accurate the prediction. Unlike beauty, for an individual chosen at random, correlation is weak.
I haven't seen any good studies showing that high IQ is compensated for by low EQ, and vice versa. It's the old fallacy of implying "all" when "some" is correct. EQ seems to be fairly evenly distributed across the population, as are other personality factors like charm and selling ability.
That educational attainment is often taken as a factor for measuring IQ speaks volumes about the inherent lack of repeatability and objectivity of intelligence research. What is the logic behind correlating academic success to intelligence? Beats me. Furthermore, what«s never discussed is that the higher the intellectual intelligence, the lower the emotional intelligence - high IQ scores predict low EQ - lack of empathy and lower capacity for emotional processing. The narcissistic or self-interest tendencies are evident in most so-called "intelligent" people scoring high in the IQ tests. Just look at Elon Musk for an example of high IQ-low EQ individual to see my point. What does high IQ serve for if it comes at the price of flaws in emotional processing?
(For the record, I myself am one of those high-IQ-test-scoring people - but at least I am able to acknowledge my own shortcomings in understanding and processing emotions, both mine and others', and capable of recognizing my high levels self-interest.)
I always remember Ian Deary's studies tracking whole populations across a lifetime showing that tests taken at teenagehood predict who'll do better in school, in life and on a later test when the participants are in their 70s.
I enjoyed the article as someone who has a pop-sci understanding of IQ.
>If medical tests, like tests for cancer, had the same reliability as IQ tests, they’d be throwing up false signals to the point of being unusable.
Disagree. We send out tons of low sensitivity and specificity tests. Physicians, like other professionals, often operate in a bayesian manner. The more severe (and unexplained) that the patient looks, the more likely we are to send long shot tests.
Billions of dollars of policy interventions is sufficiently impactful that it should merit consideration of all useful, even if imperfect, information. It is all the more important in that setting to know its limitations, as you are writing about.
This is a good reminder to not be satisfied with a pop-sci view of IQ. Do you have any recommended books?
«It is not based on the hardness of some known neuroscientific mechanism we’ve pinpointed that underlies intelligence. There is no causal account we can give for the biological basis of IQ that has any serious tensile strength. Most research consists of paper tests administered for an hour or two, sometimes decades ago, followed by contortion after contortion to account for the complexities of the world.»
Not "one mechanism", as that would be absurdly reductive. But to explain intelligence via a variety of interlocking neurochemical and structural mechanisms, and as a result of various mutually reinforcing virtuous loops and cognitive strategies? Really not that hard, as we know quite enough about how the brain works. It would end up a Frankenstein-synthesis of various models and levels, but together such a thing would about explain it for the most part.
It's on my to-do list, though someone motivated enough, with more time and more knowledge than I've gotten over the years, could easily beat me to it.
The paper you link to about SATs has an initial references set [Frey and Detterman, 2004; Koenig, Frey, and Detterman, 2008] that references papers that were published around or just after a time period when significant changes were made to the SAT that made it easier to prepare for it. I've met -- and I have this conversations many times with others who've had similar experiences -- people who've top SAT scores and were not way above average in their cognitive abilities and I've also known people who were able to improve their scores on subsequent attempts through preparation. Maybe thats all anomalous, but I dont think so. And thats just the very tip of the iceberg, there are deeply substantive critiques out there, I just dont have time to write a very reply right here
you don't assign a numerical score to an intellect like that one. It's too paltry a container. Which is enough to lead one to wonder about the utility of assigning a linear score of intelligence, per se. To anyone.
I think people who reify their own "IQ"s are really selling themselves short. Submerging themselves in a mass, however "elite."
I'm also not sure whether (or to what extent) the rare human individuals who demonstrate protean intellectual ability or polymath mastery of multiple disciplines, skills, and crafts are evidence that a handful of outlier off-the-charts genetically superior minds walk among the rest of us, or whether their example is a rebuke to the rest of us, for not activating as much potential as we could have, with a similar level of ability.
Intelligence is funny that way. It's possible to do a treadmill test and learn the limits of your aerobic capacity and various other markers of cardiac fitness. But an IQ test just doesn't operate with the same urgency, so there's no sure way to know if it's pushing people to the limit of their mental acuity. Motivation has a surprising amount to do with it.
Don't get me wrong, I do think there are bell curves of ability. Plural. And yes, some people are sharper than others, just in general. But if you really want to watch people step up their game, put them in a wheelhouse where they have a natural affinity. A knack. As someone once put it, "that part of a person that isn't nature or nurture, but what is it?"
Whatever it is, it isn't nothing.
I've read enough IQ references online to get the unsettling suspicion that the term is enjoying "meme popularity" of the type that it doesn't deserve. It isn't a shorthand abbreviation for the scope of human intelligence, and never will be. The verbal tests are a quite accurate measure of the academic skills required for superior school performance. If you haven't learned to read by the time you're in third grade, you won't do well at them. (Come to think of it, I've never seen or heard of a reference to an IQ test designed in any language other than English or French. I'll have to do a keyword search to see what I can find out about that.) The nonverbal tests--Raven's Progressive Matrices--are only aimed at one subset of skills: "abstract reasoning", which in this case is more like the ability to measure the next step in a linear progression by looking at visual diagrams. One interesting feature of RPM is that verbal autistics with impaired measures on verbal tests like the Weschler (WISC) often do quite well on RPM. Two other interesting features of Raven's: it's pitched as a nonverbal assessment, which it isn't; some baseline level of verbality is required in order to understand exactly what the test wants as a correct answer. That isn't automatically apparent. The other interesting feature is that because it's "nonverbal"--which is mostly the case--it no longer has "culture bias". But in my opinion RPM does have culture bias--not in the test content, but in the conclusions. The subtext of viewing RPM as equivalent to or superior to its main rival, the Wechler tests is that the skill set it measures with its linear time-space
sequencing prediction constitutes a probative measure of "abstract reasoning ability", which in turhas long been held as definitive for "Spearman's 'g'--or general intelligence. About which more here https://adwjeditor.substack.com/p/the-intelligence-of-nations
Long story, short, even Spearman demurred about what 'g' measured. I'm going to differ with him even more: I don't think the substrate of intelligence is all about the ability to perform specific abstract reasoning tricks. And the reason Abstract Reasoning gets so much positive emphasis is that it's what makes good coders. I'm not saying that possessing superior ability to do that means that someone only has a narrow bandwidth of intelligence, much less implying that superior performance is an indication of autism. That's reading the results backward, a logic error of the first order. There are obviously people with superior abilities in the skill set associated with RPM that who also demonstrate their intelligence abilites in other ways--even, rarely, in a great many other ways.
What I am saying is that superior performance at abstract reasoning alone is a very narrow ability set. Furthermore, the fact that it's often highly rewarded monetarily tends to narrow people who focus their attention on abstract reasoning professionally in correlation with the monetary reward they receive. And that's how the political economics of the Silicon Economy relate to the circles of American culture, and the greater world adjacent to that
business. So RPM is held to be the new gold standard of IQ testing: the veracity of all "IQ" tests are ultimately reliant on correlative measures, numbers based on selected verbal criteria chosen for the purpose of interpretation. And the criteria shown are factors like advanced schooling, and income, and occupation. Is it any surprise that a society going through a time that materially rewards the narrow skill set measured by RPM is going to view those results as a probative measure of general intelligence? Also, the intelligence testing industry, currently challenged in explaining the disparity--studies showing improvement of up to 2 standard deviations improvement with RPM over the WISC, by verbal autistic test takers--for test supposedly measuring the same quality, 'g', general intelligence. Especially given that some recent studies are also showing the obverse: some high performers on the Weschler see their scores decline with RPM. So cultural bias factors are still in the mix on this subject.
The inclination to view IQ score numbers as proving something permanently real about innate intelligence potential--"because numbers, science"--is also about Culture. "IQ" is a "text meme" of the worst sort: brief, catchy, utterly misleading.
You have shown that the SMPY has some limitations. But you seem to be implying that we should take this as evidence against the claims that prodigies destined for greatness can be identified early, and that there is no plateau of ability. It isn't. You seem to have an unreasonably low prior on the existence of innate prodigies and super-geniuses
The article that you link shows a researcher supporting single digit percentage heritability doesn't actually show what you claim it shows. The article says that a polygenic score for patients with neuroimaging data (with only 27k samples) explained 7.6% of the variance in g.
PGS variance explained != heritability! That's like reporting benchmark results for your machine learning model before its finished training.
The low IQ heritability estimates you do find in the literature such as https://pmc.ncbi.nlm.nih.gov/articles/PMC6411041/ all seem to have the same issue: they estimate SNP heritability based on UK Biobank's fluid intelligence test, but they fail to account for the fact that the test sucks! Gold standard IQ tests have a test-retest correlation of >0.9. UK Biobank's is short, so the test-retest correlation is 0.61. This is massively deflating estimates of SNP heritability, and thus broad sense heritability!
They calculate SNP heritability of 0.19-0.22 when actual SNP heritability (after adjusting for the crappy test) is about 0.3.
But that's just SNP heritability. A good portion of the variance in IQ comes from rare variants (population frequency <1%), and about 20% of it comes from non-linear effects that are going to be very hard to capture without much larger sample sizes.
I have yet to find a credible IQ heritability estimate that's lower than 0.5
The biggest thing I took away from my Instrument Development class in grad school was that an instument is only valid when used for it's intended purpose. The IQ test was originally created to classify French orphans with cognitive delays into categories that could be used to group their educational needs by the program supporting them. Taking IQ measurements outside of this context automatically makes them invalid; the context has changed and the instrument for deciding what an individual's IQ is is no longer applicable. Sure, we can acknowledge that defferent instruments have been designed and used over the years to try to quantify intelligence - we certainly aren't using the same test the French orphans were given- but we've completely shifted the purpose of IQ from grouping students with similar abilities to recieve education suited to them, to making IQ a predictive measure of mental ability and success! And how can a body of research be considered solid on such a shifting foundation?
False. A measurement can be valid for a variety of contexts, particularly when it's measuring something primary. Besides which mere correlation is sufficient for it to be predictively useful.
Thanks for publishing this article, it could not have done a better job at filling gaps in my understanding of the topic. Really shifted the way I think about things.
IQ is a good predictor of outcomes -- on aggregate, and the larger the sample, the more accurate the prediction. Unlike beauty, for an individual chosen at random, correlation is weak.
I haven't seen any good studies showing that high IQ is compensated for by low EQ, and vice versa. It's the old fallacy of implying "all" when "some" is correct. EQ seems to be fairly evenly distributed across the population, as are other personality factors like charm and selling ability.
Chris langan is a con man
That educational attainment is often taken as a factor for measuring IQ speaks volumes about the inherent lack of repeatability and objectivity of intelligence research. What is the logic behind correlating academic success to intelligence? Beats me. Furthermore, what«s never discussed is that the higher the intellectual intelligence, the lower the emotional intelligence - high IQ scores predict low EQ - lack of empathy and lower capacity for emotional processing. The narcissistic or self-interest tendencies are evident in most so-called "intelligent" people scoring high in the IQ tests. Just look at Elon Musk for an example of high IQ-low EQ individual to see my point. What does high IQ serve for if it comes at the price of flaws in emotional processing?
(For the record, I myself am one of those high-IQ-test-scoring people - but at least I am able to acknowledge my own shortcomings in understanding and processing emotions, both mine and others', and capable of recognizing my high levels self-interest.)
I always remember Ian Deary's studies tracking whole populations across a lifetime showing that tests taken at teenagehood predict who'll do better in school, in life and on a later test when the participants are in their 70s.
Watching the followers of IQism argue small details is about as amusing as watching people argue about horoscopes, or theology.
Not as entertaining however. The astrology crowd tends to be better looking and the theology crowd has better music.
What I am saying is if you are going to have faith in mitcholodrians---sorry G you should at least be easy on the eyes or able to sing Amazing Grace.
I enjoyed the article as someone who has a pop-sci understanding of IQ.
>If medical tests, like tests for cancer, had the same reliability as IQ tests, they’d be throwing up false signals to the point of being unusable.
Disagree. We send out tons of low sensitivity and specificity tests. Physicians, like other professionals, often operate in a bayesian manner. The more severe (and unexplained) that the patient looks, the more likely we are to send long shot tests.
Billions of dollars of policy interventions is sufficiently impactful that it should merit consideration of all useful, even if imperfect, information. It is all the more important in that setting to know its limitations, as you are writing about.
This is a good reminder to not be satisfied with a pop-sci view of IQ. Do you have any recommended books?
>Do you have any recommended books?
Hmm people who are followers of IQism might enjoy:
https://en.m.wikipedia.org/wiki/The_Turner_Diaries
If you are looking to leave your religion I would recommend this good (and very funny) primer on it
https://en.m.wikipedia.org/wiki/Extraordinary_Popular_Delusions_and_the_Madness_of_Crowds
A book from the 1800s and a fictional piece from a white nationalist in the 70s. Unserious recommendations.
IQ discourse remains unhinged.
«It is not based on the hardness of some known neuroscientific mechanism we’ve pinpointed that underlies intelligence. There is no causal account we can give for the biological basis of IQ that has any serious tensile strength. Most research consists of paper tests administered for an hour or two, sometimes decades ago, followed by contortion after contortion to account for the complexities of the world.»
Not "one mechanism", as that would be absurdly reductive. But to explain intelligence via a variety of interlocking neurochemical and structural mechanisms, and as a result of various mutually reinforcing virtuous loops and cognitive strategies? Really not that hard, as we know quite enough about how the brain works. It would end up a Frankenstein-synthesis of various models and levels, but together such a thing would about explain it for the most part.
It's on my to-do list, though someone motivated enough, with more time and more knowledge than I've gotten over the years, could easily beat me to it.
"Oh, what a tangled web we weave, when first we seek to sort instead of help to achieve."
The simple truth is that nature sets the range of possibilities and nurture/circumstance determines the actual outcome. It is not rocket science.
On IQ, near the bottom half of my post:
https://open.substack.com/pub/federicosotodelalba/p/comment-on-we-were-selected-tracing?r=4up0lp&utm_campaign=post&utm_medium=web&showWelcomeOnShare=false
The paper you link to about SATs has an initial references set [Frey and Detterman, 2004; Koenig, Frey, and Detterman, 2008] that references papers that were published around or just after a time period when significant changes were made to the SAT that made it easier to prepare for it. I've met -- and I have this conversations many times with others who've had similar experiences -- people who've top SAT scores and were not way above average in their cognitive abilities and I've also known people who were able to improve their scores on subsequent attempts through preparation. Maybe thats all anomalous, but I dont think so. And thats just the very tip of the iceberg, there are deeply substantive critiques out there, I just dont have time to write a very reply right here
you don't assign a numerical score to an intellect like that one. It's too paltry a container. Which is enough to lead one to wonder about the utility of assigning a linear score of intelligence, per se. To anyone.
I think people who reify their own "IQ"s are really selling themselves short. Submerging themselves in a mass, however "elite."
I'm also not sure whether (or to what extent) the rare human individuals who demonstrate protean intellectual ability or polymath mastery of multiple disciplines, skills, and crafts are evidence that a handful of outlier off-the-charts genetically superior minds walk among the rest of us, or whether their example is a rebuke to the rest of us, for not activating as much potential as we could have, with a similar level of ability.
Intelligence is funny that way. It's possible to do a treadmill test and learn the limits of your aerobic capacity and various other markers of cardiac fitness. But an IQ test just doesn't operate with the same urgency, so there's no sure way to know if it's pushing people to the limit of their mental acuity. Motivation has a surprising amount to do with it.
Don't get me wrong, I do think there are bell curves of ability. Plural. And yes, some people are sharper than others, just in general. But if you really want to watch people step up their game, put them in a wheelhouse where they have a natural affinity. A knack. As someone once put it, "that part of a person that isn't nature or nurture, but what is it?"
Whatever it is, it isn't nothing.
I've read enough IQ references online to get the unsettling suspicion that the term is enjoying "meme popularity" of the type that it doesn't deserve. It isn't a shorthand abbreviation for the scope of human intelligence, and never will be. The verbal tests are a quite accurate measure of the academic skills required for superior school performance. If you haven't learned to read by the time you're in third grade, you won't do well at them. (Come to think of it, I've never seen or heard of a reference to an IQ test designed in any language other than English or French. I'll have to do a keyword search to see what I can find out about that.) The nonverbal tests--Raven's Progressive Matrices--are only aimed at one subset of skills: "abstract reasoning", which in this case is more like the ability to measure the next step in a linear progression by looking at visual diagrams. One interesting feature of RPM is that verbal autistics with impaired measures on verbal tests like the Weschler (WISC) often do quite well on RPM. Two other interesting features of Raven's: it's pitched as a nonverbal assessment, which it isn't; some baseline level of verbality is required in order to understand exactly what the test wants as a correct answer. That isn't automatically apparent. The other interesting feature is that because it's "nonverbal"--which is mostly the case--it no longer has "culture bias". But in my opinion RPM does have culture bias--not in the test content, but in the conclusions. The subtext of viewing RPM as equivalent to or superior to its main rival, the Wechler tests is that the skill set it measures with its linear time-space
sequencing prediction constitutes a probative measure of "abstract reasoning ability", which in turhas long been held as definitive for "Spearman's 'g'--or general intelligence. About which more here https://adwjeditor.substack.com/p/the-intelligence-of-nations
Long story, short, even Spearman demurred about what 'g' measured. I'm going to differ with him even more: I don't think the substrate of intelligence is all about the ability to perform specific abstract reasoning tricks. And the reason Abstract Reasoning gets so much positive emphasis is that it's what makes good coders. I'm not saying that possessing superior ability to do that means that someone only has a narrow bandwidth of intelligence, much less implying that superior performance is an indication of autism. That's reading the results backward, a logic error of the first order. There are obviously people with superior abilities in the skill set associated with RPM that who also demonstrate their intelligence abilites in other ways--even, rarely, in a great many other ways.
What I am saying is that superior performance at abstract reasoning alone is a very narrow ability set. Furthermore, the fact that it's often highly rewarded monetarily tends to narrow people who focus their attention on abstract reasoning professionally in correlation with the monetary reward they receive. And that's how the political economics of the Silicon Economy relate to the circles of American culture, and the greater world adjacent to that
business. So RPM is held to be the new gold standard of IQ testing: the veracity of all "IQ" tests are ultimately reliant on correlative measures, numbers based on selected verbal criteria chosen for the purpose of interpretation. And the criteria shown are factors like advanced schooling, and income, and occupation. Is it any surprise that a society going through a time that materially rewards the narrow skill set measured by RPM is going to view those results as a probative measure of general intelligence? Also, the intelligence testing industry, currently challenged in explaining the disparity--studies showing improvement of up to 2 standard deviations improvement with RPM over the WISC, by verbal autistic test takers--for test supposedly measuring the same quality, 'g', general intelligence. Especially given that some recent studies are also showing the obverse: some high performers on the Weschler see their scores decline with RPM. So cultural bias factors are still in the mix on this subject.
The inclination to view IQ score numbers as proving something permanently real about innate intelligence potential--"because numbers, science"--is also about Culture. "IQ" is a "text meme" of the worst sort: brief, catchy, utterly misleading.
You have shown that the SMPY has some limitations. But you seem to be implying that we should take this as evidence against the claims that prodigies destined for greatness can be identified early, and that there is no plateau of ability. It isn't. You seem to have an unreasonably low prior on the existence of innate prodigies and super-geniuses