Honest question that keeps bothering me.
In the absence of reasonably strong natural selection pressure to select for IQ, how could IQ not be falling over time?
In the absence of reasonably strong natural selection pressure to select for IQ, how could IQ not be falling over time?
Academics often stereotype “jocks” and high social status seekers as stupid. However, it often requires brains to succeed in sports and social interactions. But it is technically difficult to measure high “intuition”. I know some very very smart people that fail academically (I know they are smart because I see them achieve seemingly impossible outcomes, not because I have their skills). I strongly suspect that selecting for high non-academic skills will select for general intelligence. If one lacks skill X (e.g. the stereotypical nerd[1] with low social skills) then one usually lacks the ability to recognise people that are highly skilled in skill X (and worse often assumes the skill is useless or denigrates those with the skill or thinks they could be highly skilled if they wanted to).
There could be bubbles of selection pressure - subgroups where high IQ leads to having more kids. So long as the subgroup intermingles, then there is a population level pressure for higher intellect.
It is possible that unsmart people remove themselves from the gene pool before reproduction, or unsmart people reproduce less.
One or two outlier smart men that have thousands of children could have a massive selection pressure. Are we not all descended from Ghengis Khan?
Smartness has thousands of factors, and selection pressure on some hidden factors could easily have an outcome on general intelligence.
[1] Counterpoint “Being smart seems to make you unpopular” implies popular people are not smart: http://www.paulgraham.com/nerds.html
This is somewhat tongue in cheek, obviously. But to spell out my point, genetic inheritance is way more complex than most of the comments here are treating it.
If you can’t confidently explain how people with brown hair can keep having red-headed kids, it might be challenging to understand why average parents can produce smart kids (or vice versa).
Change randomly a random line of code in any source code, and tell me how often it happens to work better than before.
IQ at best measures something that correlates with SAT. And with better education, less exposure to damaging pollutants, etc. it should always be on the rise (as demonstrated by the Flynn effect; an effect which this poor paper desperately tries to refute).
IQ research has always been about proving the superiority of one race over others, this superiority doesn’t exist, but that doesn’t stop these pseudo-scientist from trying. They bend the definition of “intelligence” and device test batteries (and in this case, interpret test battery) in skewed and bias ways to manipulate results like these. Regrettably media outlets like the Popular Mechanics and lifestyle journalists like Tim Newcomb take these researchers at their words and publish their results, despite their results pretty much being lies.
It is incredibly arguable if during an obesity crisis if population wide health is actually improving and if population wide health isn’t improving that could certainly contribute to lower IQ. We’re also seeing population wide declines of health in other ways like sperm count. Food is becoming less nutritious as soil depletes. Our fish stocks being about to collapse is going to be another hit against brain health as omega 3s will become rarer in the diet.
I think the point being made more generally about IQ tests testing the wrong things is very valid and I do agree with it, but it extends beyond just IQ testing, it also raises questions about standardised academic testing. What I will point out though that any rebalancing of IQ tests or standardised tests at this point is likely to become an intensely political affair because these tests are used to justify gatekeeping access to status and societal resources, and any new tests would necessarily be far worse researched than existing tests, so I wouldn't expect current IQ testing methodology to be upended any time soon.
The heritability of IQ is only well established within true believers of a pseudo-science tightly linked with the eugenics movement. Most psychologists today believe that the supposed heritability was observed because of bias within the research. And given the people who were doing these research in the 1970s and the 1980s, and their motivation for doing those, there is no question on what these biases were. Some of the researchers went so went quite far in bending the data such that it would fit their narrow—and racist—world view. They tried really hard to define intelligence such that it would make rich white people smarter, they were regrettably successful for far to long, but ultimately failed.
Your anecdotal evidence of high IQ parents (ugh!) having high IQ children is the same anecdotal evidence that sociologists have been describing for decades that high SES parents have high SES children, and is the main reason for why parents with high SAT scores are likely to have children with high SAT scores.
What IQ researchers discovered was basically the same thing that Marx described in 1867, class, however the eugenics were no communists, and instead of providing the simpler explanation, that society rewards the ruling elite, and wealth inherits, the eugenics went all conspiratorial and blamed other races for their perceived decline in society.
* IQ is real, measurable and heritable. The evidence for this is overwhelming.
* Nobody argues about the broad heritability of other human traits such as hair/eye color, height, athletic ability and the like.
* The argument over IQ is a consequence of terrible historical experiences with eugenics and racial discrimination. Many have adopted the quasi-religious viewpoint that IQ is not heritable to sidestep the discussion.
* As a consequence, social policy resembles the cycles and epicycles of Ptolemy's cosmology. Namely, all manner of social, economic and historical outcomes which are explained parsimoniously by understanding IQ as heritable are instead attributed to a Rube-Goldberg machine of racism, class warfare and the like.
* Accepting IQ as heritable does not, in an enlightened society, require acceptance of racism or classism, any more than people are forced to discriminate against those who, say, are genetically weaker athletes due to low relative VO2 levels.
* Social policy could be enhanced and better targeted by targeting those at the lower end of the IQ curve with subsidies such as basic income.
* Accepting IQ as real, heritable and measurable represents one of the only paths out of the present morass of corrupt political patronage programs around specific groups, just as rejection of Ptolemy's worldview enabled turning away from the demon-haunted world of religion.
If you're going to build a whole chain of logic, one that attempts to solve racism somewhere in the middle and ends with the "demon-haunted world of religion", it's useful to clearly define your terms first.
in both of those cases, as in all things genetic, expanding the ceiling is a far different matter. There is no known treatment I could have been given to enable me to run a 2 hour marathon. Similarly, there is no known way to cause a 100-IQ person to reliably test at a 140 IQ.
That said, progress is being made on artificial intelligence and genetics, so that could all change.
In traditional psychometrics intelligence is usually operationally defined in terms of the tests them selves. These tests correlate broadly with SAT scores and we can probably agree that disabilities and environments exists which gives people obvious disadvantage when taking the SATs, and that those people should be accommodated accordingly.
Given that you accept the operationally defined term for intelligence, how should we treat group difference in IQ any differently than how we treat (or aspire to treat) group difference in SATs? In other words, why should we care about IQ at all?
I believe it is worth studying and debating the definition of intelligence. I believe modern IQ tests do a reasonable job of crystallizing a value which is both meaningful and useful. In general, the goal is to quantify an individual's mental potential, which might be understood as their processor speed, amount of RAM in their brain, pre-programmed learning algorithm, and so forth. As with any concept in social sciences it's difficult to define it perfectly, but I believe it's worth the effort.
As for why we should care?
1. Western societies spend incredible amounts of resources on programs to equalize opportunity for people. Large fractions of this money in most western nations are allocated based on what I view to be a misunderstanding of what enables a person to prosper financially or otherwise. Examples include universal preschool and the like. Accepting the reality of IQ would assist in eliminating ineffective programs and allocating capital more effectively.
2. The quasi-religious doctrine of universal racism is an existential risk to modern liberal democracy, and it is built fundamentally on the false premise that IQ is environmental or doesn't exist. Eliminating that premise would allow consideration of other explanations for differential outcomes between groups that don't rely on accusations of hatred and bigotry.
3. Major research institutions across America and abroad, as well as large corporations, risk decreasing the rate of technological and economic progress by implementing programs built on a quasi-religious premise that people are treated vastly unequally for reasons having nothing to do with their capability. Accepting IQ as a valid science and explanation would not only de-taboo important potential areas of research, it would eliminate costly and wasteful efforts which will never bear fruit, as they seek to address problems which don't even exist.
4. An incorrect understanding of the causes behind achievement gaps provides onramps to corrupt political participants who take advantage of the basic logical fallacy that "false statements can imply anything" to redirect funding and attention away from pressing issues. Concretely, this results in death and violence resulting from failure to properly apply the law and failure to differentiate between what is true and what is false. "Without vision, a people perish."
5. Acceptance of IQ enables creation of tiered magnet schools, trade schools and other opportunities which benefit all of society, particularly those who are at the bottom of the economic ladder but who test high. Instead, at least in America, the trend is toward the elimination of all magnet programs because they are "racist." The harms here are obvious, and they all stem from an unwillingness to even consider that IQ exists and might be genetic.
6. Refusal to discuss IQ leads to it being something that is whispered about behind closed doors, but cannot be discussed openly. This directly harms those who are often (and often wrongly) associated with groups that might be thought to have lower IQs. Bringing the reality of IQ into the open enables a real conversation about it, and it allows confronting racists on much more solid ground, since the debate is no longer undergirded with taboos and untruths.
7. Acceptance of IQ allows targeting social programs toward the truly needy, accounting for the reality that in modern human life, IQ is the variable that best correlates with material success. This would eliminate injustices like affirmative action programs going to wealthy immigrants from other nations instead of those truly in need. It levels the playing field and could serve as a basis for rational policy such as targeted universal basic income.
8. AI research will ultimately force us to accept IQ as largely genetic. Accepting IQ now will avoid some sort of schism in the coming decades over this question, and allow a more rational discourse over AI's role in our lives and how to best harness it and avoid its risks.
Is that sufficient?
> * Encouraging higher IQ parents to have more children through subsidies, thereby increasing the likelihood of future technological innovations assisting all mankind.
This is a schoolbook example of a eugenicist argument. Are you sure you want to go there?
I’m gonna assume that you meant something different than what I took from this, and you are not a eugenicists. However I do want to speak a little about why eugenicists are wrong.
The problem with trying to select for IQ is that there is no broad consensus about what constitutes a good intelligent trait. There are thousands of traits that work differently in thousands of situations. When there is no consensus, somebody must take authority. And if that authority has nefarious reasons, than we are pretty screwed. More likely no such trait, nor sets of traits exist. As Charles Darwin him self demonstrated, there is value in diversity. By not selecting for a single trait, and allowing our cognitive abilities to vary as much as possible, there is way more chances of something beneficial to our species to develop and be selected for.
Now this doesn’t mean we shouldn’t accommodate for disabilities. However it isn’t 1908 any more. We have better tests and metrics to detect disabilities, and we have better means of accommodating. IQ has run its course. We don’t need it anymore. The science has advanced, and the theory is obsolete.
And this ties to the above post, and other posts you’ve done in this tree.
You seem to think there is some scientific is pretty sound and there is some suppression going on:
> 6. Refusal to discuss IQ leads to it being something that is whispered about behind closed doors, but cannot be discussed openly. This directly harms those who are often (and often wrongly) associated with groups that might be thought to have lower IQs. Bringing the reality of IQ into the open enables a real conversation about it, and it allows confronting racists on much more solid ground, since the debate is no longer undergirded with taboos and untruths.
If you think that, you’d be wrong. Modern psychology looks for behavior, if a model predicts behavior, your pretty good. IQ does no such thing. So perhaps it is sociology, not psychology and is looking for population statistics, well... IQ is pretty bat at that too. There are number of other metrics which does that better. The simplest one being school grades. And to apply Occam’s razor, why invent an entire new construct intelligence when grades suffice.
We don’t not discuss IQ. It has been done extensively for well over a century now. and IQ has simply lost to better theories. There is no taboo, just sore loosers that keep on and on about a theory that holds no relevance any more. Just look at The Bell Curve it’s been almost 30 years and we are still talking about it, despite it being a schoolbook example of how to do bad science. We finished talking about N-rays and phrenology a long time ago, it is time we do so with IQ as well.
IQ is dead, it was never anything more than a bad theory which took way too long formally die.
This assertion is rather indicative of the social attitudes that are paired with IQ-obsessed worldviews. Western societies might attempt to equalize opportunity based on the belief in the equality of outcomes now, but these sorts of programs were effected long ago on the basis of egalitarian ideals that sprang from the Enlightenment. Even if IQ revealed any such "biotruths" (which would be debated to the end of time anyway), it would not reverse centuries of Western thought which is based on equal opportunity.
In short, this view completely misunderstands how Western society actually responds to differing abilities between people. It's akin to supposing that society would tear down wheelchair ramps in order to allocate resources to those who can walk unassisted.
It's not even how many non-Western societies handle inequality among populations. China has had preferential treatment to ethnic minorities even back in imperial times:
https://en.wikipedia.org/wiki/Affirmative_action_in_China
And India, even back to the days of the Raj:
https://en.wikipedia.org/wiki/Reservation_in_India
> incorrect understanding of the causes behind achievement gaps provides onramps to corrupt political participants who take advantage of the basic logical fallacy that "false statements can imply anything" to redirect funding and attention away from pressing issues.
It's quite naive of you to suppose that any pseudoscientific evidence to the contrary wouldn't still be used to support those positions. If anything, in the hypothetical world where differences were shown to be immutable from birth, it would only strengthen the call to allocate resources to those who are less fortunate. It might normalize such a position in perpetuity, as it would then become a problem born not only of recent centuries of exploitation, but evolutionary timescales. Beware your faith in biotruths, for they can be just as easily weaponized against you.
> AI research will ultimately force us to accept IQ as largely genetic.
A non sequitur as confidently stated as it is vapid. One could say an AI wrote it, but ChatGPT is at least smart enough to hedge its bets.
If this is the goal, and we want to measure specific physical capabilities we know exist, why do we do it entirely by having people sit down and take tests and not by measuring their brain directly?
(It's because we don't know what the specific physical capabilities are, which is why we're pretending a descriptive statistic is causative.)
Cognitive psychologists don’t use IQ (nor intelligence for that matter) in their models. Psychologists that do use IQ are doing so in scientific isolation (which is a red flag) and are stuck with the same models that were created in the 1970s, a sign of a dying field.
Of course people invested in IQ will continue to research it while there is funding available. So whomever is conspiring to silence IQ research isn’t doing a good job since IQ research keeps being funded, and IQ research keeps being published (including in the article the OP links to).
Cognitive scientists of course read some of these studies, and respond with new studies, most of them don’t use IQ and are able to predict behavior just as well, and if not better. Some of them even compare models with IQ to models without IQ, almost always does the one without IQ perform better (sources below). That is what I mean when I say cognitive psychologists don’t use IQ.
* van der Maas, H. L. J., Molenaar, D., Maris, G., Kievit, R. A., & Borsboom, D. (2011). Cognitive psychology meets psychometric theory: On the relation between process models for decision making and latent variable models for individual differences. Psychological Review 118(2):339-56 https://www.researchgate.net/publication/50393518_Cognitive_...
* van IJzendoorn, M. H., Juffer, F., & Poelhuis, C. W. K. (2005). Adoption and Cognitive Development: A Meta-Analytic Comparison of Adopted and Nonadopted Children's IQ and School Performance. Psychological Bulletin, 131(2), 301–316. https://doi.org/10.1037/0033-2909.131.2.301
* Ritchie, S. J., Bates, T. C., & Deary, I. J. (2015). Is education associated with improvements in general cognitive ability, or in specific skills? Developmental Psychology, 51(5), 573–582. https://doi.org/10.1037/a0038981
* Dennis, M., Francis, D., Cirno, P., Schachar, R., Barnes, M., & Fletcher, J. (2009). Why IQ is not a covariate in cognitive studies of neurodevelopmental disorders. Journal of the International Neuropsychological Society, 15(3), 331-343. https://www.cambridge.org/core/journals/journal-of-the-inter...
(I find it helpful to remember that lipstick-wearing is highly heritable despite zero genetic determination, and number of toes isn't very heritable at all despite total genetic determination.)
In particular, you can't convincingly go from discussing the seemingly profound effects acknowledging IQ heritability will have on racism, in order to avoid "demon-haunted" religious arguments, to a shrug and a handwave about genotypic (and epigenetic) effects vs. environmental effects. With due respect to your good-faith attempt to establish a logical baseline to this whole situation, the demons are haunting your argument, not those of people who'd push back on it.
It's an earlier rebuttal and you can find more precise and current ones now, but Ned Block's heritability piece is a good starting point for this stuff (you can just Google for "ned block heritable", the SERP will be dozens of links to it.)
Edit:
I read a bit of Ned Block's piece. I believe he more or less immediately dismisses my view as "Extreme geneticism". While I don't agree that different groups in a given country grow up in the same circumstances, I also don't believe this matters much, if at all. If life teaches anything, it's that it's incredibly difficult to construct a machine that absolutely prevents the success of one group or another. Life is diverse and adaptable and finds a way. There are plenty of examples of groups historically facing terrible environments who nonetheless prospered.
Block also complains about a lack of sufficient data on the question of IQ. Fine, but one must immediately ask why there is such a lack of data. And that returns us to the demon-haunted world of quasi-religious opposition to such research.
Bottom line is, if you want to argue for the Rube Goldberg machine of -isms that produce differential outcomes in groups, prove it. I believe that, just as in other areas of human endeavor such as athletics, the prior should be that genetics are the most important input.
We can ask why there isn't evidence of genetic determinism in intelligence, and you can claim it's because of demonic opposition to the research, and I can claim that it's because studies into those genetic connections haven't been productive, but either way, heritability statistics don't give you an answer. It's one thing to suggest that a paucity of results should motivate more studies, but what you're doing is closer to suggesting that a paucity of results is evidence for the claim. Obviously, no.
He is not just dismissing your view as "extreme geneticism". He literally explains how fallacious it is to conflate heritability with genetic determination. Using that to make judgments about genetic determination of IQ is therefore methodologically flawed and the only intellectual honest course of action is to dismiss these types of judgments outright.
> I don't understand how your logic holds together once you concede that heritability doesn't mean "genetically determined".
And you wrote:
> You literally just said that you were using "heritability" as a synonym for "genetic determination". No, you can't do that.
I'm not sure which sentence I'm supposed to take as you saying what you mean, but yes, I can say I'm using "heritability" as a synonym for "genetic determination."
And, of course there is plenty of evidence that IQ is genetic. That's most of the reason why it's become a taboo area of research. If people were sure it was a waste of time, they'd just tell researchers to go ahead and check. Instead, they taboo it because they're afraid of what it would mean for their view of society if it turned out to be true, which it surely is.
As I mentioned in another thread, your claim that it's not genetic should not be the prior here. That would be like me claiming that people's maximum height being environmental should be the prior. It's just preposterous. Of course physical traits are primarily genetic. The brain is a physical object, therefore its structure is primarily genetic.
Later
You've extensively edited your comment. In response to those edits: if you look back at my comments, I think you'll see that I haven't made a claim about genetic determinism at all, only that the evidence you've presented doesn't support it.
Or in other words, the reason you're not smarter is because nobody's invented a surgery to make you smarter yet. And the reason you're not less smart is that nobody's hit you over the head with a rock. If either of those scenarios happened, your ancestry wouldn't get to object much.
If you want a theory of intelligent to include a notion of general intelligence which can be measured, you must be able to defend which aspects of behavior falls in the category of intelligent, and which not.
Playing chess and jumping on furniture both require plenty of cognitive skills, and brain functions to work together and produce a singular outcome, both are goal driven, both takes years of practice, both have varying skill levels.
Now the cognitive functions these skills require may both be inherited, you may even find the specific genes which encodes either behavior (and name them the furniture jumping gene and the chess playing gene if you will). However when you assign chess playing as intelligent but not furniture jumping, then you’ve made an arbitrary choice, which you need to justify. (You also have the option of not defining intelligence to begin with; which what I personally would pick).
But more importantly, even if you find your justification, you’ve only found one gene of intelligence which inherits, you haven’t found a gene for general intelligence, so you haven’t shown that intelligence is determined by your genes, only the ability to play chess well.
Then when you find all the genes for all behavior you consider intelligence, you still haven’t shown that they co-inherit with each other, that is, you haven’t shown that people with the chess playing gene tend to also have the sudoku solving gene, and the IQ test taking gene, etc. For there to be a single general intelligence, and for this general intelligence to be determined by genetics, than this is what is required. Unless of course general intelligence is a real thing and there is a gene for it which allows you to play chess better than others, solve Sudoku faster than others, answer more questions on IQ tests correctly, etc. But this is a rather extraordinary claim, don’t you think?
I agree with that reasoning! We defined intelligence the way we do because it "works." If jumping on chairs were what advanced modernity, we would test for that instead. And, that too would "work" because it would surely be a marker for people who were likely to be successful in life.
Social sciences aren't going to be able to provide specific answers to your questions in the near term. No, there is no single gene or trait that codes for "intelligence" as we define it. But, that does not mean we can't come up with intelligence tests which correlate strongly with that definition and also correlate strongly with various measures of success in life. Such measures also correlate strongly with society-wide success (measured by a group's progress along the tech tree).
Actually I’m gonna repeat a couple of paragraph from the first post you responded to: https://news.ycombinator.com/item?id=35517130
> Your [faeriechangling] anecdotal evidence of high IQ parents (ugh!) having high IQ children is the same anecdotal evidence that sociologists have been describing for decades that high SES parents have high SES children, and is the main reason for why parents with high SAT scores are likely to have children with high SAT scores.
> What IQ researchers discovered was basically the same thing that Marx described in 1867, class, however the eugenics were no communists, and instead of providing the simpler explanation, that society rewards the ruling elite, and wealth inherits, the eugenics went all conspiratorial and blamed other races for their perceived decline in society.
(For what it's worth: research suggests that adopting low-SES children into high-SES households is associated with as much as an 18 point increase in IQ test scores.)
You're selectively citing research on adoption. In fact, there's plenty of research showing that gains are transitory and parental IQ is a better predictor of IQ in late teen years than is the high-SES environment. This whole "mystery" is what prompted folks to ask Jensen to start studying Head Start, as it wasn't clear it was doing any good. The problem is these interventions don't work. They don't work because IQ is genetic.
"That doesn't work because IQ is genetic" doesn't even make sense as a sentence. It implies that something being "genetic" means it's immutable. That's not even how genes work. But it's how people thought they worked in the 1960s, which is where your cite comes from.
Here's a nice take-down of him that took me 3 minutes of googling to find: https://cremieux.medium.com/is-eric-turkheimer-a-scientist-e...
I remember my first university assignment when studying psychology back in 2008. It was an essay on the nature vs. nurture debate. I remember going through the sources and deeming the debate kind of stupid. Then I got to Turkheimer, particularly the legendary 2000 article of “Three Laws of Behavior Genetics and What They Mean” which begins with:
> The nature-nurture debate is over. The bottom line is that everything is heritable, an outcome that has taken all sides of the nature-nurture debate by surprise.
And concludes with:
> The gloomy prospect [non-shared environment between siblings accounting for a large part of behavioral variability] looms larger for the genome project than is generally acknowledged. The question is not whether there are correlations to be found between individual genes and complex behavior—of course there are—but instead whether there are domains of genetic causation in which the gloomy prospect does not prevail, allowing the little bits of correlational evidence to cohere into replicable and cumulative genetic models of development. My own prediction is that such domains will prove rare indeed, and that the likelihood of discovering them will be inversely related to the complexity of the behavior under study.
Later in a 2003 study he then goes on and demonstrate that almost all of the variability can be explained by environmental effects (E) and genetic and environmental interaction effects (G × E). None of the previous readings even considered interactions and always concluded with x% E + (100 - x)% G for some x. (EDIT: Catching up my reading I actually see that more recent behavioral geneticists are even using G × E² in their models, that is, the environment also interacts with it self, and that interaction also interacts with you genotype, making for much richer models).
I turned in my paper concluding that obviously there was a flaw in previous studies that don’t look at interactions. Like why is this even being debated any more? I off course got a failing grade for the essay, being of low SES (sorry IQ) my essay skills obviously lacking as I didn’t have the skill (sorry intelligence) to formulate a coherent argument. Thankfully my boy Eric Turkheimer came to the rescue by concluding that actually in a high learning environment like a university in a country which grants equal education to everybody that my skills can be improved (sorry, I mean, my intelligence is malleable), so that I could graduate 3 years later with a first grade.
No, nobody can talk bad about my boy Turkheimer.
* Good genetics, bad environment = bad outcome
* Bad genetics, good environment = bad outcome
* Good genetics, good environment = good outcome
* Bad genetics, bad environment = bad outcome
So, it's basically an "and" gate.
I see nothing wrong with this reasoning, and it makes perfect sense to me. A couple points, however.
1. You'd still have to ask the question of which of the variables is malleable.
2. There would remain this question along the lines of, "let's say you took 1000 children from low-SES environments and put them in high-SES environments. What happens?" My recollection of the literature on this is it's somewhat sparse (because this doesn't happen that often), but that there's a strong regression to the genetic intelligence in the teenage years. BUT, even if you argue all such studies are methodologically flawed, the US government, with its $N trillion budget could easily simply run this experiment and find out what happens. Why don't people advocate to run this experiment?
Edit: Just to sidestep bad-faith responses, here's how the experiment would work. You run a program where all low-SES babies put up for adoption starting on a random day become eligible for something such that high-SES families who adopt them get some massive tax break or even subsidy while raising them. They would be required to show proof they spent $Nk per year on private schools, that they live in a high-SES neighborhood the entire time, and there would be home visits to ensure the kid is being treated appropriately by the parents. Any families where this isn't the case would be excluded.
Now just to clarify, G + E is a different model from G + E + G×E. Many twin studies in the past century were done on a pretty homogeneous demographic, across a very slim slice of SES (mostly inside high SES; as you correctly pointed out). This skewed the models such that it completely missed the G×E part, this is, if you don’t measure across different SES, you’ll miss how SES interacts with genotypes. What Turkheimer did was actually measure heritability inside low SES, and his results were that in a G + E model, the proportions were flipped. That is, instead of G=60% and E=40%, he and his team found E=60%. When your get results that flip in this way, it is a pretty clear indicator that you have interactions between your main effects (G and E), so Turkheimer fitted a model which includes the G×E interaction[1] (which all researchers with some level of statistical literacy would do) and found that almost all of the variance previously attributed to genes, would perish into the interaction effects.
You can read the study here. The methodology is not that far off from what you are proposing (just without the controlled interventions; which is bound to cause some biases anyway). https://www.researchgate.net/publication/8997472_Socioeconom...
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1: Note the models are a bit more complicated than G+E. Usually they use an ACE model, with Genotype (A), shared environment (C), and non-shared environment (E; also known as gloomy prospect), and than model A + C + E. In Turkheimer, et. al. (2003) the model was s*SES + A*(a + a'*SES) + C*(c + c'*SES) + E*(e + e'*SES) where a,c,e are the main effects of A, C, E; s the main effect of SES; and a', c', e' are interactions of a,c,e with respects to SES.
The interaction effect only failed to replicate in countries with less SES disparity than the USA.
> The estimated size of the interaction varies between countries, which may result from a narrower range of socioeconomic deprivation in the countries where the effect is not found (Tucker‐Drob & Bates, 2016). If the hypothesis were true, the ability to detect genetic variants associated with educational attainment would be attenuated by a limited range of socioeconomic variation, which may explain discrepant findings in different contexts.
> As a consequence, social policy resembles the cycles and epicycles of Ptolemy's cosmology. Namely, all manner of social, economic and historical outcomes which are explained parsimoniously by understanding IQ as heritable are instead attributed to a Rube-Goldberg machine of racism, class warfare and the like.
Now I find it interesting you would say this while also believing that “High SES correlates with IQ” and “You're just measuring the same thing, going round and round in circles.”
Now a sibling post goes into why IQ and SES aren’t the same thing, but suppose for the sake of argument that it is. SES is pretty much just a function of wealth, it can be measured by things like your family income, education and occupation, all pretty straight forward. You don’t need constructs such as intelligence, g-factors, you don’t need to do factor analysis to find correlations within massive tests etc. You just take the income, education, and occupation, and you have your SES.
Now, if I were to look for epicycles within a model which predicts “success”, IQ would be a prime candidate here. Nothing predicts you income as well as your parent’s income, the same applies to education and occupation. So if these are the things you’d define as “success”. Or as you put it:
> If jumping on chairs were what advanced modernity, we would test for that instead. And, that too would "work" because it would surely be a marker for people who were likely to be successful in life.
Now ponder this for a moment. What if instead of creating a construct called intelligence and using that as the predictor for this “success” as you call it, instead we allow society to be unequal. That we grant different people different access to things like good jobs, healthcare and education. Now if said society would enforce this limited access by using something we can actually and objectively know runs in families, say money, fame, and valuable assets, that those that have less of these things get less access to the tings which grants you “success”. Wouldn’t we have a pretty good model to predict “success”.
Now leaving aside this thought experiment (and snark on my part) IQ seems like a giant epicycle of you theory of success. Instead of forming our social policies around intelligence, wouldn’t it be better to form them around something we know is a prime cause of hindrance, inequality.
Now you know my political stance here, so I’m not afraid to say: Solidarity among the working class! Eating the rich! Those are the real solutions. Not being gaslit by the wealthy elite that we are stupider then they.
What people want to understand is the preconditions of the high SES status. Not everyone who achieves high SES has rich parents. Take Japanese people in America. They were placed in internment camps in the 1940s, yet today they have substantially higher median incomes than whites. How is this possible?
Ashkenazi Jews faced unimaginable hardship for centuries, yet they manage to have remarkable success. Jews have won 26% of all Nobel Prizes in sciences, more than 100x what would be expected by chance. Arguing that's environmental is just silly. Their environment couldn't have been worse!
Now to your overall political point, I actually disagree there too. I honestly think it's possible that this quarantining of IQ science and cancel culture are looked favorably upon by elites because they know that they preserve the status quo. In fact, policies that embrace IQ and intelligence research would be far more expensive. Rather than pretending an 80 IQ person is going to be able to become a lawyer, society would have to reckon with the hard truth that such a person is probably going to need meaningful monetary assistance his entire life. Accepting IQ would probably mean something like reparations for slavery would actually have to be paid -- not out of some guilt trip, but because many of these folks need the money to keep up in society. And, you're not going to be able to get away with a single lump sum, because they're going to need the help every year.
So, even with an anti-rich ideology, I just don't think your arguments hold water. You're falling for a head-fake. Haven't you ever wondered why so many super-wealthy people embrace liberal politics? This is why.
Before I get into the bulk of my argument I want to address this first:
> Haven't you ever wondered why so many super-wealthy people embrace liberal politics? This is why.
Now I’m not super well versed in polling numbers, but I was under the impression that the ultra-rich voted overwhelmingly conservative, that is, the proportion of conservative voters are higher among the most wealthy group of the population. However, perhaps you know more about polling numbers among demographics than I.
And now to the bulk of my arguments.
So what you are describing in your above post is that there is variation in the system, as people can move across classes. In a previous system, namely feudalism (or the caste system in India), this wasn’t possible. By abolishing feudalism we allowed people to move across the SES spectrum. Although capitalism allows some movement, there is still plenty of friction. Perhaps intelligence is this friction but I need to see more evidence to believe that. Or to apply Marx’s razor: “Never attribute to stupidity that which is adequately explained by class interest.”
Your examples all have simpler alternative explanation. Not all Japanese Americans were detained in concentration camps, some—particularly the wealthier—were able to self-exclude, meaning they had a place outside the exclusion zones, and were than able to return to their wealth after executive order 9066 was rescinded. This was a huge minority of course, but it speaks volumes that it was wealth, not intelligence, which determined who could and could not self-exclude. There have also been thousands of Japanese people that have migrated since 1944, and Japanese internal policies make it so that since 1945 most Japanese migrants are of the mid- to upper classes.
Your example with Ashkenazi Jews is just acknowledging the fact that culture exists and often follows racial lines such that people from a common background seek similar education and occupations. Note that SES includes both education and occupation. Also note that critical race theory explains race as a cultural phenomena instead of biological. So this observation is not surprising in an SES model as long as some horizontal movement between classes is allowed.
Reading about Ashkenazi Jews actually lead me to this excellent summary by Vox in the matter: https://www.vox.com/policy-and-politics/2019/12/30/21042733/... In short, this can be explained with statistics as “Small average differences make big differences to outliers” so even if you believe IQ is a good metric for intelligence (and you shouldn’t), and Ashkenazi Jews do have higher IQ on average (which they might), this is still not enough to establish there is any genetic basis for the group difference, as this is exactly what you’d expect to see given the statistics. When you only look at the extremes, the expected value also becomes extreme. So your statistics about > 100x is simply wrong.
Forbes found they leaned slightly right in a survey with a very low participation rate. The idea that the Democrats are bad for business is wildly overstated. Lots of businesses benefits from things like direct government spending and a highly educated workforce for their businesses to be successful. Others like virtually anybody in Oil & Gas is going to lean way right.
The democrats have been leaning wealthier and wealthier every election though, seemingly because of a partisan split between high-education and low-education voters.
I understand you think your view is scientific, but it just isn't. There is plenty of data on many, many traits being genetically determined, and IQ is no different. IQ absolutely has relatively less research, which enables you to poke holes in what is there. The reason there is less research is because of a quasi-religious belief that studying such a thing is "wrong." That belief would not exist if there weren't a substantial fear that such research would show conclusively that people have predetermined genetic ceilings for IQ (as they do for many other traits such as maximum VO2, height, etc.).
I see no convincing argument here that environmental explanations should be the prior. It's just like religion. Activists have essentially outlawed IQ research, then insisted on compelling evidence to change their minds. Such situations remind me of Galileo and his telescope.
The saddest part of all of this is watching society tear itself apart, laboring under the false assumption that the culture is beset by racist boogiemen. While evil people do undoubtedly exist, the vast majority of people are well-meaning. Being honest about IQ research would enable people to see that.
You suppose IQ to be genetically determined. That's fine, but you stated previously that it was heritable, which is a claim you could marshal evidence for, unlike your current claim. It's for that reason that it's important to distinguish the two concepts. It's you who brought in the claim that the evidence for heritability is "overwhelming". By your new definition of the term, I've reduced "overwhelming" to "hand-wavy" (your new evidence seems to consist of "other things are known to be genetically determined, and research into IQ determination has been "outlawed"). Not great.
It's unsurprising that people are reluctant to talk about this stuff given the level of rigor it's approached with.
I don't think we're really having a productive discussion here, since we're talking past each other, but so I'll just reiterate a key point you're ignoring:
It is virtually impossible to research IQ in Western universities, and doing so risks a loss of tenure.
Now, you're asking for rigor in proving to you that IQ is genetic. I'm arguing that genetic determination of IQ should be the prior, thus a priori no rigor is needed. And, the environmentalists should be saddled with the necessity of disproving genetic determination, not the other way round. You offer no refutation of this argument.
But, your demand for rigor is already preposterous on its face, because researching this topic is virtually impossible! And, those who do research it are immediately slandered as white supremacists and targeted with methodological critiques that, if applied equally to all social sciences, would sink essentially all well-meaning studies in this area.
I genuinely don't understand what mental gymnastics people go through to convince themselves that, in the face of essentially every other important human trait being genetically determined (even sexual orientation!), IQ is somehow exempt. My best guess it's a consequence of wanting to "belong" in a society that has rendered my views taboo. That was a key function of Catholicism in the 1400s in Europe. Groupthink has its place.
In any event, if you reply, please specifically explain to me why I should take your demands for more research data seriously when people who argue what you're arguing have made such research unfundable.
You suppose me to be attempting to refute an argument that IQ is genetically determined. I don't have to do that. No valid argument has been presented that it is. Your original argument supposed that the evidence for genetic determination was "overwhelming", but you believed that because you mistook the term "heritability" as a synonym for "genetic", when it is in fact a ratio "genetic/everything".
As for research funding: you also can't get a grant to prove that the Earth is flat, and that fact is persuasive to some people, who have taken to renaming the atmosphere the "atmosflat". Generally, you want your logic to be stronger than that of flat-Earthers.
That doesn't make your supposition that IQ is genetically determined wrong (I think it's wrong, but don't pretend to have demonstrated that). It just makes your logic faulty.
Responding to your message below. It is the case, as you can see in this screenshot: https://imgur.com/a/q0VjGgJ
Note the lack of a reply button. You must be a real hoot in person.
https://github.com/minimaxir/hacker-news-undocumented#hidden...
I don't understand what is being claimed. Are you suggesting that twin studies show (or would show) that children inherit lipstick-wearing behavior from their parents, even when raised apart from them?
If this behavior is inherited, but is not genetic, what is the claimed mechanism by which it is inherited?
In the case of IQ, we can identify the model through the exogenous quantity "relatedness." We know exactly how related monozygotic twins are (100%) and the expectation for dizygotic twin relatedness (50%), so we can use the fact that these quantities are known to figure out other model parameters.
Since we know that dizygotic twins are exactly half as related as monozygotic ones in the limit, we know the the genetic effect is going to be equal to 2(r_{MZ} - r_{DZ}) and excess resemblance cannot be attributable to genes, since dizygotic twins are not >50% related (on average).
Therefore, we can use it to directly figure out the fraction attributable to genetics, then we can see the excess relatedness as due to shared environments, and the residual as the unshared.
This is a pretty good high-level summary:
Causation can be determined by experiments (either "natural experiments" or intervention studies), but obviously these are both technically impossible and usually immoral to do on humans. Some fields like (…parts of) economics and medicine do experiment design properly, but many others (genetics, psychology, nutrition) just kind of ignore it and hand-wave something about P-values. This is ok if you're only using genetics to create 23AndMe ancestry charts, but it won't be once we actually have gene editing capabilities to inform.
That this happened here is evident from the fact that you've been reduced to arguments like "IQ is genetically determined because my cat can't play chess".
https://www.etymonline.com/word/heritable#:~:text=%22capable....
https://dictionary.cambridge.org/dictionary/english/heritabi...
The Cambridge definition linked just above is particularly on point:
"The ability of a disease or characteristic to be passed from a parent or grandparent to a child through the genes"
--
Yes, I know it's convenient to redefine terms like gender and heritability to fit what's politically popular. I get it. But, don't gaslight me by telling me I'm redefining the words. As you can see, I could have used this word in 1300s France and been understood as speaking about traits derived from one's parents through being their offspring.
--
As for my argument about a cat playing chess, I'm just trying to give you the simplest possible example so you can see that your doctrinaire position on this subject is insane.
I'm happy to keep going on like this, because you're surfacing a lot of pernicious "race science" myths in their absolute most easily rebutted form, which is (and here truly there is no snark intended) a sort of service to the thread.
I quote, from the National Cancer Institute (a scientific institution you may have heard of): "The proportion of variation in a population trait that can be attributed to inherited genetic factors."
You're just lying or misinformed. Either way, it's starting to get hard to be civil with you.
To drive a wedge between these two concepts, he is drawing on examples like the ones put forth in Ned Block's paper, like how wearing of earrings is (or at least used to be) almost perfectly correlated with having XX chromosomes, despite the fact that being biologically female does not directly cause the wearing of earrings. Thus, according to him, your interpretation of heritability is bogus, unscientific, race science, etc.
Is this a good argument? I don't think it is. While XX chromosomes may not directly cause the wearing of earrings (or lipstick), genetics clearly are a link in the causal chain that ultimately creates the variance observed when heritability is measured. Women wear earrings because they are biologically women and we live in a culture where women wear earrings. The two factors combine to produce the effect.
The most charitable interpretation of tptacek's point is that there are other, non-genetic inputs into the directed graph of causes, that these non-genetic factors combine with the genetic factors to produce the variance, and that the non-genetic factors are morally more important. For example, clearly culture plays a role in why only women wore earrings when Block wrote his paper. This is even more clear when we see that this is no longer the case, and now it is reasonably common for men to wear earrings too.
The logical conclusion is that non-genetic factors can interact with a genetic factor to produce a difference that the genetic factor itself could not have produced. For example, you could imagine a scenario where racial prejudice and discrimination caused teachers to give up on black kids based on nothing but their race, causing them never to achieve the IQ they could have achieved if they had been given the same educational attention as a white kid. This would be a case where an IQ difference is heritable, even though the true blame lies with how people are treated based on their race.
But is that the world we live in? Given the strong heritability of IQ, and the enduring disparities that are frustratingly durable even through decades of remarkable social change, I think the onus is on the people proposing such an extra non-genetic factor to identify and measure it, in a way that can be isolated and empirically evaluated. Otherwise the argument is isomorphic to: "you're a race scientist if you think that height differences between population groups could be caused by genetics."
The extra, non-genetic factors that people would propose (socio-economic status especially) can be controlled for, and do not seem to explain the gap. Most teachers seem to value the success of racial minorities as highly, if not more highly, than other students. I think that some cultural anti-patterns in black culture could certainly play a part (like cultural pressure against being a good student), but that has been decreed to be just as verboten as the genetic hypothesis.
https://web-archive.southampton.ac.uk/cogprints.org/230/1/19...
>Your anecdotal evidence of high IQ parents (ugh!) having high IQ children is the same anecdotal evidence that sociologists have been describing for decades that high SES parents have high SES children
No, I've seen people who grew up with low SES but had parents/grandparents who were consistently A students or were employed in prestigious intellectual jobs, and lo and behold, they ended up doing better in things like school than you would expect for somebody of their SES.
>Bias, racism
I'm just going to turn this around on you. Why should I not believe you're bias and racist and simply want to disprove IQ testing so as to undermine the social position and access to societal resources certain groups have as a result of IQ testing and things like it such as standardised testing? There's plenty of profit in painting certain groups as oppressors whose success is actually just robbery, and not an accident of genetic difference, since this consequently justifies racist measures to correct this inequity. People can benefit from such notions both directly and socially through association with a popular movement.
I'm pretty sympathetic to the idea of IQ lacking validity because I can't make strongly convincing arguments that IQ predicts anything besides academic success and it's hard to then argue our measures of academic success aren't themselves arbitrary and disconnected from practical utility. It's arguably too hard and too arbitrary to distill "intelligence" down to a few standardised tests and prove those tests have cross-domain validity.
I don't have much sympathy to the idea that IQ is not heritable based on nothing but ad hominem and the idea this position is anti-racist because it's not what I read from the evidence.
https://www.sciencedirect.com/science/article/abs/pii/S01602...
It's a twin study. Here's a quote: "Mean IQ scores were modestly higher among those from higher SES backgrounds, but the magnitude of genetic influences on IQ was uniformly high across the range of SES." SES means "socio-economic status".
Honestly, the evidence for heritability of IQ is very strong. Arguing against it, in my opinion, borders on arguing that vaccines don't work. I actually understand why people do it (there's a lot of very bad history in how IQ data has been used). But I just think it's more important in the long run to tell the truth and find solutions based on the truth.
This is an interesting opinion. So vaccine research has produced a number of successful trials, the research is keeps furthering more knowledge, we develop new techniques, new models, new successful predictions, and new products which yield more successful trials. I consider this a healthy field of science and engineering.
Now how does IQ research fair next to vaccine research. The first IQ test was authored in 1908, not to measure intelligence among populations, but to assess learning disability. Since then IQ researchers have been trying to prove that IQ differences exists among populations. They have created and standardized new types of IQ tests that are supposed to show this difference exists. They have spent the past 100 years doing this, using fancy statistical methods, but have so far failed to convince the other fields of science (especially other fields within psychology), nor have they convinced policy makers (though they were pretty close during the eugenics craze). They have no theory of behavior other then this hypothetical general intelligence. They have no models that predict behavior, they have no products other then their intelligence tests, the tests are constantly criticized, have no successful double blind trials to show for them selves. The techniques are the same as in the 1970s, just plain old pen and paper tests with some factor analysis to spot the correlation they were hoping to spot (some would say, preconditioned or biased to spot).
If I were to be generous I would categorize IQ research among string theory as a scientific dead end. They had a theory, it didn’t go anywhere, and now the rest of the field has moved on. However given the history of IQ research and their ties to the eugenics movement, I’m not gonna give them this benefits. I believe IQ research, with the exception of Alfred Binet him self, was always about putting people in racial categories to show that one group was superior to another, with a made up construct they call intelligence.
* SAT tests largely amount to IQ tests and are used extensively for college admissions in the US. College degrees from top US universities remain the most sought after degrees in the world.
* Magnet schools in urban areas regularly utilize IQ tests or their equivalents to elevate students into advanced coursework. This enables students to rise above their socioeconomic status.
* European secondary schools regularly use tests that correlate with IQ tests to track students into programs leading to universities versus technical schools. These tests help coordinate society and deploy human capital where it is most needed.
* Even the US military uses IQ tests to avoid accepting recruits who don't meet a certain standard. This aids in ensuring the security of western nations.
IQ testing could be used in additional areas, such as:
* Encouraging higher IQ parents to have more children through subsidies, thereby increasing the likelihood of future technological innovations assisting all mankind.
* Assisting in identifying individuals who need more support from society.
* Better understanding the causes behind social ills like poverty, drug addiction, homelessness and the like. Understanding that an individual's IQ is a stronger determinant of economic outcome than other variables, such as race, is a step toward a society with more solidarity and less friction.
I appreciate that you have a bias against intelligence testing, and I understand its genesis (your mention of the "eugenics craze" makes that clear). I'm suggesting society aim toward an enlightened view of these things where people's IQs don't identify them as "greater" or "lesser". Wishing IQ away is unlikely to work, particularly in a world about to experience the arrival of super-intelligent AI systems.
Do you really view lower IQ individuals as equal if you want them to have less children (at least as a ratio of total births)? The slippery slope argument would be that you're a few steps from sterilizations.
Are we sure that "super-intelligent AI systems" wouldn't displace intelligent individuals? Seems like they'd certainly be the ones wielding a middle-ground (say, GPT-6/7/8) most effectively but if an AI reached 100% coverage of human skills (imo unlikely in our life time) we wouldn't need any theoretical physicists.
This is the crux of your comment and its a huge statement. Do you have evidence supporting this claim?
Although IQ differences between individuals have been shown to have a large hereditary component, it does not follow that disparities in IQ between groups have a genetic basis.[11][12][13][14] The scientific consensus is that genetics does not explain average differences in IQ test performance between racial groups.[15][16][17][18][19][20]
And a quick search on Google Scholar:
https://psycnet.apa.org/doiLanding?doi=10.1037%2F0033-295X.1...
https://web-archive.southampton.ac.uk/cogprints.org/230/1/19...
Sure, but this is not the claim I originally quoted. I was taking about heritability, and you're taking now about disparities between groups.
Nevertheless it seems you agree the heritability of IQ is well established, which you were denying originally.
First of all I do not believe that IQ is a good metric for intelligence, nor that intelligence is a useful scientific construct.
Secondly, there are whole subthreads here that go into the nuances of what heritability means for measured IQ. From what I’ve gathered is that findings which assign 50-80% of the variance to inheritance neglect to account for covariance, or use very biased assumptions about G×E correlations or G×E interactions which skewes the results in favor of genetic explanations, i.e. they are biased.
> Although IQ differences between individuals have been shown to have a large hereditary component ...
You have written both statements ...
It has been shown from biased studies that IQ has a large hereditary component, where these studies failed to account for genetic × environmental interaction and covariation.
By the way the wikipedia article it self goes into these nuances and caveats. Reading it, it is pretty clear that there may be a large inheritance factor to IQ, while at the same time large IQ differences between individuals have no genetic basis.
If you see the latter as problematic, and any research that incorporates it as flawed, then how do you provide scientific basis for the assertion that intelligence is not at all inheritable? Marx certainly isn't one.
I don’t think we can construct a philosophical understanding on what intelligence is, as we are always bound to select an arbitrary set of traits which describes the bias of the researcher more than a useful model of behavior.
How do I provide scientific basis for the assertion that intelligence is not at all inheritable?
I don’t, but others do. If you believe you can select a set of traits which constitute an intelligent personality, which some researchers do (or rather assume for the sake of argument that it exists), then what you get is a large environmental effect on the supposed intelligence, a large cofactor of environment and inheritance, some genetical factor, but a close to 0 genetic bases for any group differences.
This is really a double tier rebuttal which states: Even if you are right (and you are not) that general intelligence exists, and that IQ is a useful measure of general intelligence (which is also false), you are still wrong that there is a genetic basis for any perceived inheritance of this supposed intelligence.
Twin studies [1]. Different parents, socioeconomic statuses, possibly countries. Sustained significant statistical effects. That’s the genetic component of intelligence.
[1] https://www.nature.com/articles/mp2014105 first four references
In plain English: the twin studies show us how similar twins are, but they don’t tell us how true the movie Idiocracy is.
"Individual differences in intelligence tend to cluster in families" [1].
There are studies which include "parents in a twin design." They found "no significant shared environmental influence [between the adoptive and non-adoptive children]: all variance could be explained by additive genetic factors and environmental factors that are not shared by children raised in the same family" with "significant genetic transmission for intelligence...found at all ages" (§ 1.3).
[1] https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&d...
The previous response did not directly say if those studies suggested high-IQ parents resulted in high-IQ children. So did it?
I get that you're probably trying to take this thread in a different direction from raw heritability numbers, but the parent commenter was, correctly, rebutting a flawed previous argument based solely on heritability.