59 minutes ago, pinball1970 said:

You can look University entrants by ethnicity in the UK too. Whites are the lowest and have consistently been the lowest since 2006.

https://www.ethnicity-facts-figures.service.gov.uk/education-skills-and-training/higher-education/entry-rates-into-higher-education/latest/

10 minutes ago, sethoflagos said:

I wonder how you excuse away the findings of The Socioeconomic Attainments of Second-Generation Nigerian and Other Black Americans: Evidence from the Current Population Survey, 2009 to 2019

How is it that such a cognitively challenged group as Nigerian American women outperform both their menfolk and second-generation Asian men, never mind you bleached, inbred banjo-plucking hillbilly halfwits?

Well one (I would think fairly obvious) explanatory factor for both of these cases would be selection bias. Whites in their native countries come from all backgrounds, while minority ethnic groups are more likely to be fairly recent immigrants who were selected from the higher strata of their home countries. So you're comparing the cream of the crop of Nigerian women (estimates for mean IQ of Nigeria range from 70 to 90) against the entire White American population, or elite Chinese against all White British. There's also the secondary fact for the stats about Nigerian women that educational attainment and raw IQ are not perfect correlates.

For those British university stats there's also no mention of gender as far as I can see.

Edited November 27Nov 27 by xenog123

4 hours ago, exchemist said:

Substantial? I admit it's been years since I last read about this, but my impression was that while IQ tests did measure a difference, it was so small that it seemed just as likely to be to do with aptitude at doing the tests, for reasons of background, culture and upbringing, as it was to any genetic effect. Do you have a source in mind that we can take a look at?

2nd that. Seems to be a persistent ignoring of culture/nurture in this malodorous sidebar.

42 minutes ago, sethoflagos said:

How is it that such a cognitively challenged group as Nigerian American women outperform both their menfolk and second-generation Asian men, never mind you bleached, inbred banjo-plucking hillbilly halfwits?

LMAO. Ah, but those women are an elite group which means... oh wait...they experienced better nutrition and care and a richer stimulating learning environment in childhood and particular cultural emphasis on diligence and task persistence.

24 minutes ago, xenog123 said:

So you're comparing the cream of the crop of Nigerian women (estimates for mean IQ of Nigeria range from 70 to 90) against the entire White American population, or elite Chinese against all White British.

You realize you are supporting the nurture side of the argument with these observations, right? These elites are getting the nurture environments which seem to bring them up to the functional levels common in wealthy nations. How are you missing this?

32 minutes ago, xenog123 said:

Whites in their native countries

Which would clearly exclude the Americas, for example.

34 minutes ago, xenog123 said:

from the higher strata of their home countries

By what measure?

11 minutes ago, TheVat said:

2nd that. Seems to be a persistent ignoring of culture/nurture in this malodorous sidebar.

LMAO. Ah, but those women are an elite group which means... oh wait...they experienced better nutrition and care and a richer stimulating learning environment in childhood and particular cultural emphasis on diligence and task persistence.

You realize you are supporting the nurture side of the argument with these observations, right? These elites are getting the nurture environments which seem to bring them up to the functional levels common in wealthy nations. How are you missing this?

No, that doesn't follow. I just mean elites in terms of useful skills/education, who presumably would be more likely to have the ability to immigrate. If you're assuming that this distinction is due solely to environmental factors then you're begging the question.

7 minutes ago, sethoflagos said:

Which would clearly exclude the Americas, for example.

By what measure?

In general immigrants are more likely to be admitted if they are rich/educated/skilled, all of which correlate with IQ. If you wanted to be super thorough you'd have to look at the relevant country's immigration policies I guess but some basic filtering is evidently there (criminals, super low IQ people).

3 minutes ago, xenog123 said:

In general immigrants are more likely to be admitted if they are rich/educated/skilled, all of which correlate with IQ.

No. The first generation of that population mainly gained entry to the US via the Diversity Immigrant Visa lottery scheme.

ie. by luck. Try again.

A pretty good explanation of the origins and predictions of IQ testing, including the 'corruption' and mis-use by Americans and NAZIs,

Notice that all the 'predictors' that IQ tests provide are all correlations, not causes.
I wonder how a stable and advantaged childhood and teen-age years, with good schooling, would correlate with the metrics of success ( education, income, wealth, etc. ) identified in the video.

Maybe the most important correlation is how responsive caregiving and nutrition, nurturing interactions, and a stimulating educational environment affect IQ scores.

22 minutes ago, sethoflagos said:

No. The first generation of that population mainly gained entry to the US via the Diversity Immigrant Visa lottery scheme.

ie. by luck. Try again.

I mean it says right in that article that applicants have to meet some requirements for education, job training and work experience. There's also the self-selection factor, in that those who choose to apply are more ambitious, driven, higher IQ.

23 minutes ago, MigL said:

A pretty good explanation of the origins and predictions of IQ testing, including the 'corruption' and mis-use by Americans and NAZIs,

Notice that all the 'predictors' that IQ tests provide are all correlations, not causes.
I wonder how a stable and advantaged childhood and teen-age years, with good schooling, would correlate with the metrics of success ( education, income, wealth, etc. ) identified in the video.

Maybe the most important correlation is how responsive caregiving and nutrition, nurturing interactions, and a stimulating educational environment affect IQ scores.

Yeah clearly environmental factors are huge as well, I'm not denying that. The only reasons one should care about heredity or group differences are, imo:

1. Zeal for scientific truth

2. To inform better policy making

In the West the assumption that race or gender based disparities are mostly or entirely due to discrimination has informed a lot of social justice-style corrective policy that is probably just totally wrong-headed or impractical.

1 hour ago, xenog123 said:

Well one (I would think fairly obvious) explanatory factor for both of these cases would be selection bias. Whites in their native countries come from all backgrounds, while minority ethnic groups are more likely to be fairly recent immigrants who were selected from the higher strata of their home countries. So you're comparing the cream of the crop of Nigerian women (estimates for mean IQ of Nigeria range from 70 to 90) against the entire White American population, or elite Chinese against all White British. There's also the secondary fact for the stats about Nigerian women that educational attainment and raw IQ are not perfect correlates.

For those British university stats there's also no mention of gender as far as I can see.

Similar for GCSE results and boys are out performed by girls in every ethnic group except traveller of Irish heritage.

Source: Ethnicity facts and figures Gov. UK.

57 minutes ago, MigL said:

A pretty good explanation of the origins and predictions of IQ testing, including the 'corruption' and mis-use by Americans and NAZIs,

Notice that all the 'predictors' that IQ tests provide are all correlations, not causes.
I wonder how a stable and advantaged childhood and teen-age years, with good schooling, would correlate with the metrics of success ( education, income, wealth, etc. ) identified in the video.

Maybe the most important correlation is how responsive caregiving and nutrition, nurturing interactions, and a stimulating educational environment affect IQ scores.

Veritasium rocks BTW!

6 minutes ago, pinball1970 said:

Similar for GCSE results and boys are out performed by girls in every ethnic group except traveller of Irish heritage.

Source: Ethnicity facts and figures Gov. UK.

The ethnic factor there could still be explained by immigrant selection. The gender trend is quite clear though. As far as I know recent IQ testing hasn't shown a growing disparity between males and females, so my first thought would be to ascribe that to just differences in work ethic or enthusiasm moreso than pure cognitive ability. I think historically males and females had similar mean scores on formal tests line this so that's a remarkable divergence, especially if IQ hasn't changed. But I'd have to do more research.

Anyways I've got to take a break from this for a bit.

7 hours ago, exchemist said:

There are several instances of them coming to believe their opinions must be right, just because of who they are. Linus Pauling and vitamin C? H

There is something I think called the Nobel syndrome, where Nobel price winners go off on the deep end once they get it. Curie was a notable exception (as she went on to win a second price, instead). But I also meant that hi grew up in a different time, where gender and racial differences were just accepted as facts and are therefore less inclined to review information that counters it, as a good scientist should. The issue is often that scientists might inadvertently provide credibility to such notions, though they are way outside of their expertise.

3 hours ago, xenog123 said:

Well for IQ differences between Blacks and Whites in America the data is pretty much everywhere - here's one source though: https://www1.udel.edu/educ/gottfredson/30years/Rushton-Jensen30years.pdf

As I mentioned before, Rushton (whom you seem to cite here) has been pretty much outdated and he created a body of literature who tried to link IQ with race. It was fairly prominent in the 90s I would say. A key issue even then was that he was a psychologist and tried to invoke biological concepts (such as reproductive strategies) which he clearly only poorly understood. His contemporaries already questioned some of the results based on their own studies (there has been a quite some exchange with Nisbett, for example). And in the later works Rushton increasingly seemed to slice and dice his data to accommodate his view while dismissing other studies, which created some bad blood with his colleagues. There is a huge spinoff, many questioning suitability of standardized IQ tests in various contexts (there was a paper from Wicherts discussing it in the Sub-Saharan context). The long and short of it is that certain psychometric measures considered to be universal, are not. Only once certain environmental components are fulfilled (e.g. nutrition, basic schooling, stable environment, as @MigL mentioned) do this measures become comparable. One especially strong correlated was also found in vocabulary development (which in turn is associated with education). In multiple studies using IQ test without vocabulary tests the IQ gap pretty much vanished (studies from the 2000s).

But even some of the basic assumptions you have mentioned are not quite correct. For example:

3 hours ago, xenog123 said:

Interestingly what you actually find is that this disparity between Black and White scores persists even with the Flynn effect - so even as the measured IQ of both groups increases over the decades the gap remains roughly the same.

I believe that is what Jensen and/or Rushton have repeated in their papers. Yet in Flynn's work back dating back to the 90s have already talked about the diminishing gap, which Rushton later tried to argue away (which in turn lead to a whole slew of related discussions). The point is that Rushton's work keeps cementing a hard delineation, something that is not found by most other researchers and, importantly, makes little biological sense, from our understanding of population genetics. Even if disregarding ongoing gene flow, Rushton's hypothesis was delineated among black as the lowest racial IQ group, whites in-between and Asians the highest. Yet, studies have shown that folks closer related to the Asian's, such as Indigenous Americans, as well as Asians with low socioeconomic status, have similar scores as black folks.

So from first principles, the biological argument was already weak, but there was a fairly recent work (I forgot the author, but could dig it out) using genome wide associated studies based on the 1000 genomes using a range of cognitive tests have failed to find any genetic links. Ultimately there is a huge body of lit that disputes this rather old claim, bolstered by improvements in our understanding of genetics. On the other side, we have Rushton and a few other researchers who not only claim a racial element, but even a hard racial delineation, essentially re-using their own arguments they came up with, when we knew less. Reviewing the full body of literature, this hard delineation is simply not supported and should at this point (or really, since around 2000) should not be taken as fact. It goes a fair bit into old men's pet theory territory (and I know a fair bit about old men and their scientific theories).

4 hours ago, sethoflagos said:

[...] never mind you bleached, inbred banjo-plucking hillbilly halfwits?

Who are you addressing here exactly? That's kind of out of line whoever the target may be. And it doesn't even really make sense to refer to a White person as "bleached" if they were born that way, if that's what you meant.

2 hours ago, CharonY said:

There is something I think called the Nobel syndrome, where Nobel price winners go off on the deep end once they get it. Curie was a notable exception (as she went on to win a second price, instead). But I also meant that hi grew up in a different time, where gender and racial differences were just accepted as facts and are therefore less inclined to review information that counters it, as a good scientist should. The issue is often that scientists might inadvertently provide credibility to such notions, though they are way outside of their expertise.

As I mentioned before, Rushton (whom you seem to cite here) has been pretty much outdated and he created a body of literature who tried to link IQ with race. It was fairly prominent in the 90s I would say. A key issue even then was that he was a psychologist and tried to invoke biological concepts (such as reproductive strategies) which he clearly only poorly understood. His contemporaries already questioned some of the results based on their own studies (there has been a quite some exchange with Nisbett, for example). And in the later works Rushton increasingly seemed to slice and dice his data to accommodate his view while dismissing other studies, which created some bad blood with his colleagues. There is a huge spinoff, many questioning suitability of standardized IQ tests in various contexts (there was a paper from Wicherts discussing it in the Sub-Saharan context). The long and short of it is that certain psychometric measures considered to be universal, are not. Only once certain environmental components are fulfilled (e.g. nutrition, basic schooling, stable environment, as @MigL mentioned) do this measures become comparable. One especially strong correlated was also found in vocabulary development (which in turn is associated with education). In multiple studies using IQ test without vocabulary tests the IQ gap pretty much vanished (studies from the 2000s).

But even some of the basic assumptions you have mentioned are not quite correct. For example:

I believe that is what Jensen and/or Rushton have repeated in their papers. Yet in Flynn's work back dating back to the 90s have already talked about the diminishing gap, which Rushton later tried to argue away (which in turn lead to a whole slew of related discussions). The point is that Rushton's work keeps cementing a hard delineation, something that is not found by most other researchers and, importantly, makes little biological sense, from our understanding of population genetics. Even if disregarding ongoing gene flow, Rushton's hypothesis was delineated among black as the lowest racial IQ group, whites in-between and Asians the highest. Yet, studies have shown that folks closer related to the Asian's, such as Indigenous Americans, as well as Asians with low socioeconomic status, have similar scores as black folks.

So from first principles, the biological argument was already weak, but there was a fairly recent work (I forgot the author, but could dig it out) using genome wide associated studies based on the 1000 genomes using a range of cognitive tests have failed to find any genetic links. Ultimately there is a huge body of lit that disputes this rather old claim, bolstered by improvements in our understanding of genetics. On the other side, we have Rushton and a few other researchers who not only claim a racial element, but even a hard racial delineation, essentially re-using their own arguments they came up with, when we knew less. Reviewing the full body of literature, this hard delineation is simply not supported and should at this point (or really, since around 2000) should not be taken as fact. It goes a fair bit into old men's pet theory territory (and I know a fair bit about old men and their scientific theories).

Yeah that was just the first study a search turned up. I haven't read Rushton's work directly but am familiar with Jensen's. As for the gap narrowing there is some evidence it might have narrowed a bit, perhaps from 1 to roughly 0.7 standard deviations below the mean, but the most recent studies that I looked at are still kind of mixed. Even if it's narrowed that much due to an improvement in the (presumably) asymmetrical life conditions that caused the disparity in the first place it still seems like a pretty massive gap. And I kind of wonder at just how much you have to equalize environmental factors anyways - does education actually improve fluid intelligence (one would think not by definition), or is it enough that one has adequate nutrition and other material necessities?

I would agree that the hard delineation idea is simplistic though.

Does the 1000 genome study you mention refer to genetic links between races and IQ or just genes and IQ in general?

51 minutes ago, xenog123 said:

Who are you addressing here exactly?

You and your kind.

52 minutes ago, xenog123 said:

That's kind of out of line whoever the target may be.

In what way?

53 minutes ago, xenog123 said:

And it doesn't even really make sense to refer to a White person as "bleached" if they were born that way, if that's what you meant.

Our local word is 'oyinbo' which literally means 'peeled'. Would that make more sense to you?

33 minutes ago, sethoflagos said:

You and your kind.

In what way?

Our local word is 'oyinbo' which literally means 'peeled'. Would that make more sense to you?

Why are you even assuming I'm white? And yes it's pointlessly rude.

4 hours ago, xenog123 said:

In the West the assumption that race or gender based disparities are mostly or entirely due to discrimination has informed a lot of social justice-style corrective policy that is probably just totally wrong-headed or impractical.

An assumption can still be correct even if some policies derived from that assumption are ineffective. And the assumption you mention is robustly supported by social science studies that look at how outcomes and disparities change when discrimination is lessened for minorities and outreach programs support childhood nurture. You haven't produced a shred of evidence that programs supporting things like nutrition, literacy, stable family life, healthy housing, arts after school, etc are "wrong-headed." And resorting to vague phrases like "social justice style" doesn't advance your position. It's just hand-waving.

2 minutes ago, xenog123 said:

Why are you even assuming I'm white?

LOL.

4 minutes ago, TheVat said:

An assumption can still be correct even if some policies derived from that assumption are ineffective. And the assumption you mention is robustly supported by social science studies that look at how outcomes and disparities change when discrimination is lessened for minorities and outreach programs support childhood nurture. You haven't produced a shred of evidence that programs supporting things like nutrition, literacy, stable family life, healthy housing, arts after school, etc are "wrong-headed." And resorting to vague phrases like "social justice style" doesn't advance your position. It's just hand-waving.

LOL.

Those kinds of programs aren't the ones I'm talking about - I'm referring to things like affirmative action. If you look at university admissions in the States, for example, you'll find that in an effort to yield a "fair" distribution ethnic groups that are more objectively qualified as measured by metrics such as GPA and exam results are discriminated against in favour of those with inferior qualifications (Chinese-American males are actually the most severely discriminated against in this regard). So in this case the idea of meritocracy is being jettisoned in favor of equity or whatever, obviously not an ideal policy.

25 minutes ago, xenog123 said:

Why are you even assuming I'm white?

A wild stab in the dark.

27 minutes ago, xenog123 said:

And yes it's pointlessly rude.

Just plain facts. I've met many of your kind over the years, and with very few exceptions, they've been bleached, inbred, hillbilly halfwits. Though I admit, most were actually crap on the banjo so for the sake of good science, I withdraw the unjustified slur.

Edited November 27Nov 27 by sethoflagos

2 hours ago, xenog123 said:

And I kind of wonder at just how much you have to equalize environmental factors anyways - does education actually improve fluid intelligence (one would think not by definition), or is it enough that one has adequate nutrition and other material necessities?

Ok, there's the vagueness again. What precisely is meant by education? Generally, when the wealthy in Nigeria are, thanks to wealth, now providing childhood nurture at what are norms in the Western middle class, there is a broad palette of educational advantages beyond just larger vocabulary and better reading skills. The best schools that wealthy families afford would offer student projects and problem-solving tasks which would impact fluid intelligence as well as crystallized intelligence. And students, not having to go to dull repetitive laboring jobs or similar after school would better integrate those cognitive skills. Again, when these Nigerian women were raised with Western norms of access and education and nurture, their scores rose to parity. If there is ambition to emigrate, that's not a selective effect for IQ but for personality traits that may not relate to IQ at all. After all, if ambition and drive correlated closely with IQ, the current US government would look vastly different.

37 minutes ago, sethoflagos said:

A wild stab in the dark.

Just plain facts. I've met many of your kind over the years, and with very few exceptions, they've been bleached, inbred, hillbilly halfwits. Though I admit, most were actually crap on the banjo so for the sake of good science, I withdraw the unjustified slur.

Uh okay man

2 hours ago, xenog123 said:

Yeah that was just the first study a search turned up.

And work from the same authors will dominant in the first couple of your searches (e.g., Rushton, Lynn, Jensen). And there is a reason for that.

It is also important that these resurgences of eugenics line of thinking happened when the "big narrative" type research saw an upswing, which includes the rise (and eventual fall) of disciplines such as sociobiology and evolutionary psychology. Lack of reproducibility and inability to resolve cofounding factors ultimately challenged the disciplines wholesale.

I would suggest to follow up your reading with folks like Nisbett, Wicherts and I think Litman for very extensive critiques to issues ranging from methodology to poor reproducibility.

2 hours ago, xenog123 said:

Does the 1000 genome study you mention refer to genetic links between races and IQ or just genes and IQ in general?

There have been quite a few on GWAS and IQ, but the one that I was thinking of, specifically looked at that in a racial context. Other studies have found SNPs that are associated (if frequently weakly) with educational attainment. If the genetic link is strong, techniques like polygenic techniques should be able to estimate heritability of such a trait. Estimates from those GWAS found that maybe around 10ish% of the variation in certain intellectual measures could be explained by genetic differences. There are similar studies looking similar and different sibling groups, trying to account for the environment (published by Lee et al In Nature Genetics, I think maybe around 2018). The follow-up I am thinking about used similar techniques to specifically look at black white divide and found an even smaller impact.

I think it is suffice to say that the stated premises are very much mired in the findings of some influential groups around the 90s and still have some proponents, but the cumulative work of many more folks have failed to validate those claims.

And again, from a biological perspective this type of category is not terribly meaningful without additional qualifiers, making the strong results purported by certain folks at least somewhat suspect.

16 hours ago, TheVat said:

Ok, there's the vagueness again. What precisely is meant by education? Generally, when the wealthy in Nigeria are, thanks to wealth, now providing childhood nurture at what are norms in the Western middle class, there is a broad palette of educational advantages beyond just larger vocabulary and better reading skills. The best schools that wealthy families afford would offer student projects and problem-solving tasks which would impact fluid intelligence as well as crystallized intelligence. And students, not having to go to dull repetitive laboring jobs or similar after school would better integrate those cognitive skills. Again, when these Nigerian women were raised with Western norms of access and education and nurture, their scores rose to parity. If there is ambition to emigrate, that's not a selective effect for IQ but for personality traits that may not relate to IQ at all. After all, if ambition and drive correlated closely with IQ, the current US government would look vastly different.

Well the logic is basically something like this - assume you have two groups of identical IQ distributions. If you're selecting some subset of one to move to the other based on even rudimentary selection criteria (high school education, some work experience, no criminal record, knowledge of opportunities in other countries) you're implicitly filtering out people below some IQ threshold, and so the minority population in the new country will have a higher average IQ than the natives.

16 hours ago, CharonY said:

And work from the same authors will dominant in the first couple of your searches (e.g., Rushton, Lynn, Jensen). And there is a reason for that.

It is also important that these resurgences of eugenics line of thinking happened when the "big narrative" type research saw an upswing, which includes the rise (and eventual fall) of disciplines such as sociobiology and evolutionary psychology. Lack of reproducibility and inability to resolve cofounding factors ultimately challenged the disciplines wholesale.

I would suggest to follow up your reading with folks like Nisbett, Wicherts and I think Litman for very extensive critiques to issues ranging from methodology to poor reproducibility.

There have been quite a few on GWAS and IQ, but the one that I was thinking of, specifically looked at that in a racial context. Other studies have found SNPs that are associated (if frequently weakly) with educational attainment. If the genetic link is strong, techniques like polygenic techniques should be able to estimate heritability of such a trait. Estimates from those GWAS found that maybe around 10ish% of the variation in certain intellectual measures could be explained by genetic differences. There are similar studies looking similar and different sibling groups, trying to account for the environment (published by Lee et al In Nature Genetics, I think maybe around 2018). The follow-up I am thinking about used similar techniques to specifically look at black white divide and found an even smaller impact.

I think it is suffice to say that the stated premises are very much mired in the findings of some influential groups around the 90s and still have some proponents, but the cumulative work of many more folks have failed to validate those claims.

And again, from a biological perspective this type of category is not terribly meaningful without additional qualifiers, making the strong results purported by certain folks at least somewhat suspect.

That's interesting to hear about new research in the field. I didn't get the impression when reading Jensen that he was actually manipulating data. In terms of "grand narrative" fallacy it seems there might be the opposite trend now towards an egalitarian spin that sees everything as socially constructed.

Those SNP studies are really not conclusive in my view, since we still have such a poor understanding of which genes are linked with measured intelligence. And I just can't fathom anyone who would do away with any hereditarian ideas entirely. Look at something like twin studies, for example. Or even the idea that you could have identical twins whose every physical trait is identical (clearly because of their shared genes) but their brains are somehow immune to this.

2 hours ago, xenog123 said:

"grand narrative" fallacy it seems there might be the opposite trend now towards an egalitarian spin that sees everything as socially constructed.

I disagree, not fully but some extent. The pendulum is moving and the issue is that it is a bit unclear if we know where to stop it. There are some isolated papers who are excessive, but they pale in contrast to the existing body of lit of strong narratives. But the egalitarian spin is not the claim that everything is socially constructed, especially if you read the papers carefully. Rather, the claim is that the social overlay is so strong, that you need extraordinary amount of data from several disciplines (and not just a simple measure as per Rushton, Jensen, Lynn and others, who are all psychologists but try to make biological arguments). I.e. the former assumption was basically everything is pre-ordained by evolution and dominated by genetics. However, biologists have moved away from that quite a bit quicker than some areas of social sciences, after realizing the complex interplay between genetics and the environment, even on the cellular level.

2 hours ago, xenog123 said:

Those SNP studies are really not conclusive in my view, since we still have such a poor understanding of which genes are linked with measured intelligence. And I just can't fathom anyone who would do away with any hereditarian ideas entirely. Look at something like twin studies, for example. Or even the idea that you could have identical twins whose every physical trait is identical (clearly because of their shared genes) but their brains are somehow immune to this.

Regarding SNPs, you wouldn't need to know which are associated with intelligence if you use GWAS methodologies. If the basis is some hidden genetic pattern, you should be able to delineate high-intelligent from low-intelligent folk across all socioeconomic and racial groups. That attempt has failed.

Regarding twin studies, in order to separate out environmental factors you would need to separate twins and e.g. have one placed in a developing country and another in a, say rich household in a developed country. Those studies have small cohorts and almost always have children originated from poor countries (adopted into a developed one), that is already being under potential harmful influences and I don't recall studies with the reverse setup. There are studies however, that have shown that heritability in twins can vary which indicates that development is not fixed. But again, there hasn't been really an argument that IQ has no heritability (which is a slightly different argument whether certain genes are associated with higher IQ, as it measures generational transmission and cannot really make a functional association), but rather the relative role between genetics and environment.

2 hours ago, xenog123 said:

Or even the idea that you could have identical twins whose every physical trait is identical (clearly because of their shared genes) but their brains are somehow immune to this.

You forget the single most important element: the plasticity of the brain. Even if if we found a genetic pattern that is directly and clearly responsible for high IQ, take this child and rear it in the dark with no social input. It would not only do badly but utterly fail an IQ test.

The point is that there is still discussion an what the psychometric measures really measure. The good thing is that some seem to measure something stable but there is a broad discussion about what they mean. And we are not even touching the biological aspects of it. And then there are the limits of natural experiments where you always slice and dice cohorts. And finally, looking at genetic traits that can bring advantages the big questions is how and how they are distributed.

Assume that there is a set of genes that make you very good at reading (say some sort of pattern recognition and recall). In a setting where reading and writing is common, that person might excel in written tests. However, the same trait in a hunter society may also be of benefit, such as for hunting. Yet, if illiteracy is the norm it might never translate to written tests. And even if folks apply a culturally appropriate test (which in itself if problematic) they might do it verbally, a test for which those genetic traits suddenly do not provide a benefit anymore.

From a biological point of view, the issue is fairly obvious, traits only manifest themselves by interaction of the molecular machinery (which adds flexibility to the genetic underlining) with the environment. It is always both and there are scenarios one or the other contributes more. These shifts tend to be dynamic and require a lot of work to untangle, even if we just use cells. To me it was always baffling that folks think that they can make strong theories and assumptions on the vastly more complicated, much vaguer and much less well understood concept of intelligence (and not to mention the issue with defining racial boundaries on top).

And another thought here. A key issue is that in social sciences, models for how these things work in concert (genetics, environment, IQ test, g test, economic status, educational attainment, etc.) are mechanistically coupled. All they see are correlations. Take this model: let's assume that there different genetic traits that somehow is attracted to another set of genetic traits. You just like folks a bit more who have a certain genetic constellation. You are more likely to give them good grades or a job. And there might be genetic traits that do the opposite. Depending on how prevalence and how social hierarchies are formed, over time you might get a genetic stratification. Then you develop tests and low and behold you see folks with certain traits on top and some on the bottom. You then decide that these traits cause the rise (which is not entirely wrong) and those also are also stably associated with psychometric measurements and twin studies would support it and so on. The issue here really is that you are really testing stratification, but without understanding the why. The latter is then filled with assumptions, which can and has in the past led to problematic outcomes.

I will end with adding that one should not overestimate the reach and meaning tests that have been designed in a specific context (again, something you learn in biological studies early on). IQ tests on certain groups like the San people would put them in categories akin to someone with high levels of mental disabilities. However put a high IQ person and a San person into their environment (wilderness Southern Africa) there is little doubt who would survive. And a person with an actual disability would likely fare even worse. In short, we do not know enough and the issue with using genetics especially in a social science context, is that the links are unclear and folks are prone to overextrapolate things (and not to knock a whole discipline, but I see psychologists being some of the worst offender here). To me a null model where you first assume no genetic influence and then try to test out how much and where and in which context, makes much more sense and seems more methodologically sound.

8 hours ago, CharonY said:

The issue here really is that you are really testing stratification, but without understanding the why. The latter is then filled with assumptions, which can and has in the past led to problematic outcomes.

8 hours ago, CharonY said:

In short, we do not know enough and the issue with using genetics especially in a social science context, is that the links are unclear and folks are prone to overextrapolate things (and not to knock a whole discipline, but I see psychologists being some of the worst offender here).

I knew a psych professor who liked to say "halo effects are everywhere."

People frequently observe traits they like and make dubious correlations with general intelligence. And video culture can promote such halo effects, causing (often unconscious ) mental associations between certain phenotypes and cognitive skills.

18 hours ago, CharonY said:

I disagree, not fully but some extent. The pendulum is moving and the issue is that it is a bit unclear if we know where to stop it. There are some isolated papers who are excessive, but they pale in contrast to the existing body of lit of strong narratives. But the egalitarian spin is not the claim that everything is socially constructed, especially if you read the papers carefully. Rather, the claim is that the social overlay is so strong, that you need extraordinary amount of data from several disciplines (and not just a simple measure as per Rushton, Jensen, Lynn and others, who are all psychologists but try to make biological arguments). I.e. the former assumption was basically everything is pre-ordained by evolution and dominated by genetics. However, biologists have moved away from that quite a bit quicker than some areas of social sciences, after realizing the complex interplay between genetics and the environment, even on the cellular level.

Regarding SNPs, you wouldn't need to know which are associated with intelligence if you use GWAS methodologies. If the basis is some hidden genetic pattern, you should be able to delineate high-intelligent from low-intelligent folk across all socioeconomic and racial groups. That attempt has failed.

Regarding twin studies, in order to separate out environmental factors you would need to separate twins and e.g. have one placed in a developing country and another in a, say rich household in a developed country. Those studies have small cohorts and almost always have children originated from poor countries (adopted into a developed one), that is already being under potential harmful influences and I don't recall studies with the reverse setup. There are studies however, that have shown that heritability in twins can vary which indicates that development is not fixed. But again, there hasn't been really an argument that IQ has no heritability (which is a slightly different argument whether certain genes are associated with higher IQ, as it measures generational transmission and cannot really make a functional association), but rather the relative role between genetics and environment.

You forget the single most important element: the plasticity of the brain. Even if if we found a genetic pattern that is directly and clearly responsible for high IQ, take this child and rear it in the dark with no social input. It would not only do badly but utterly fail an IQ test.

The point is that there is still discussion an what the psychometric measures really measure. The good thing is that some seem to measure something stable but there is a broad discussion about what they mean. And we are not even touching the biological aspects of it. And then there are the limits of natural experiments where you always slice and dice cohorts. And finally, looking at genetic traits that can bring advantages the big questions is how and how they are distributed.

Assume that there is a set of genes that make you very good at reading (say some sort of pattern recognition and recall). In a setting where reading and writing is common, that person might excel in written tests. However, the same trait in a hunter society may also be of benefit, such as for hunting. Yet, if illiteracy is the norm it might never translate to written tests. And even if folks apply a culturally appropriate test (which in itself if problematic) they might do it verbally, a test for which those genetic traits suddenly do not provide a benefit anymore.

From a biological point of view, the issue is fairly obvious, traits only manifest themselves by interaction of the molecular machinery (which adds flexibility to the genetic underlining) with the environment. It is always both and there are scenarios one or the other contributes more. These shifts tend to be dynamic and require a lot of work to untangle, even if we just use cells. To me it was always baffling that folks think that they can make strong theories and assumptions on the vastly more complicated, much vaguer and much less well understood concept of intelligence (and not to mention the issue with defining racial boundaries on top).

And another thought here. A key issue is that in social sciences, models for how these things work in concert (genetics, environment, IQ test, g test, economic status, educational attainment, etc.) are mechanistically coupled. All they see are correlations. Take this model: let's assume that there different genetic traits that somehow is attracted to another set of genetic traits. You just like folks a bit more who have a certain genetic constellation. You are more likely to give them good grades or a job. And there might be genetic traits that do the opposite. Depending on how prevalence and how social hierarchies are formed, over time you might get a genetic stratification. Then you develop tests and low and behold you see folks with certain traits on top and some on the bottom. You then decide that these traits cause the rise (which is not entirely wrong) and those also are also stably associated with psychometric measurements and twin studies would support it and so on. The issue here really is that you are really testing stratification, but without understanding the why. The latter is then filled with assumptions, which can and has in the past led to problematic outcomes.

I will end with adding that one should not overestimate the reach and meaning tests that have been designed in a specific context (again, something you learn in biological studies early on). IQ tests on certain groups like the San people would put them in categories akin to someone with high levels of mental disabilities. However put a high IQ person and a San person into their environment (wilderness Southern Africa) there is little doubt who would survive. And a person with an actual disability would likely fare even worse. In short, we do not know enough and the issue with using genetics especially in a social science context, is that the links are unclear and folks are prone to overextrapolate things (and not to knock a whole discipline, but I see psychologists being some of the worst offender here). To me a null model where you first assume no genetic influence and then try to test out how much and where and in which context, makes much more sense and seems more methodologically sound.

Well regarding the nature vs. nurture debate it seems kind of obvious it's a combination of both. I would think genes set the upper limit on IQ and then environmental factors determine the rest.

Twin and adoption studies are pretty telling - from what I recall reading if you take, say identical twins from a lower SES and place one with an upper middle-class family and one with a family of low SES, the one raised in the richer environment will end up with a higher IQ than his twin, but still lower than that of his adopted family. If environment was purely the determining factor you'd think his IQ would rise to exactly that of the adoptees.

As for what IQ measures the whole point is that it's supposed to be general intelligence, since most cognitive abilities are found to strongly inter-correlate (see culture-fair tests). For the example of the survivalist bushman with the 70 measured IQ, that sounds like saying that like, a sea sponge with no brain rivals a human's intelligence because it can survive on the ocean floor where a human being would just drown.

Edited November 29Nov 29 by xenog123

https://onlinelibrary.wiley.com/doi/abs/10.1002/ajpa.24216

American Journal of Physical AnthropologyVolume 175, Issue 2 pp. 465-476

Abstract

Objectives

Debate about the cause of IQ score gaps between Black and White populations has persisted within genetics, anthropology, and psychology. Recently, authors claimed polygenic scores provide evidence that a significant portion of differences in cognitive performance between Black and White populations are caused by genetic differences due to natural selection, the “hereditarian hypothesis.” This study aims to show conceptual and methodological flaws of past studies supporting the hereditarian hypothesis.

Materials and methods

Polygenic scores for educational attainment were constructed for African and European samples of the 1000 Genomes Project. Evidence for selection was evaluated using an excess variance test. Education associated variants were further evaluated for signals of selection by testing for excess genetic differentiation (F_st). Expected mean difference in IQ for populations was calculated under a neutral evolutionary scenario and contrasted to hereditarian claims.

Results

Tests for selection using polygenic scores failed to find evidence of natural selection when the less biased within-family GWAS effect sizes were used. Tests for selection using F_st values did not find evidence of natural selection. Expected mean difference in IQ was substantially smaller than postulated by hereditarians, even under unrealistic assumptions that overestimate genetic contribution.

Conclusion

Given these results, hereditarian claims are not supported in the least. Cognitive performance does not appear to have been under diversifying selection in Europeans and Africans. In the absence of diversifying selection, the best case estimate for genetic contributions to group differences in cognitive performance is substantially smaller than hereditarians claim and is consistent with genetic differences contributing little to the Black–White gap.

2 hours ago, xenog123 said:

Twin and adoption studies are pretty telling - from what I recall reading if you take, say identical twins from a lower SES and place one with an upper middle-class family and one with a family of low SES, the one raised in the richer environment will end up with a higher IQ than his twin, but still lower than that of his adopted family. If environment was purely the determining factor you'd think his IQ would rise to exactly that of the adoptees.

A couple points:

One, please provide citations rather than "what I recall reading," as our forum rules require you to do when requested. We need to see the data you're seeing and how it's being interpreted.

Two, twin studies are prone to sloppiness in isolating causal factors. Adopted children generally, for example, receive somewhat differential treatment from biological children in a given family no matter how good the parental intentions or the degree of wealth. There can also be overseas effects for children adopted into richer Western families, where a shift in various environment features in the first year or two of life (ambient allergens or pathogens, for one) can affect the child's development.

15 minutes ago, TheVat said:

If environment was purely the determining factor you'd think his IQ would rise to exactly that of the adoptees.

This is shifting the goal posts. No one has argued that environment is the sole determining factor. G comes from an interaction between many gene variants and the environment. The issue is whether genes are significant in differences in G between human groups.

DNA analysis has found hundreds of genetic variants that each have a very tiny association with intelligence, but even if you add them all together they predict only a small fraction of someone’s IQ score.

And heritability, whether low or high, implies nothing about modifiability. The classic example is height, which is strongly heritable (80 to 90 percent), yet the average height of 11-year-old boys in Japan has increased by more than 5 inches in the past 50 years. A similar historical change occurs for intelligence.