39 ms·

"The Bell Curve" is, let's say, highly controversial and not a good introduction into the topic. Its claim that genetics are the main predictor of IQ, which was

"The Bell Curve" is, let's say, highly controversial and not a good introduction into the topic. Its claim that genetics are the main predictor of IQ, which was very weakly supported at the time, has been completely and undeniably refuted by science in the thirty years since it's publication.

brabel 1y ago
Really? If not genetics then what is it? Just random??
- smokel 1y ago
  If it isn't nature, then it probably is nurture. Averaged over the entire population, that is indeed mostly random.
- mdp2021 1y ago
  Personal development. It's a "subtle" skill. You train it (though maybe less directly than other skills).
- pona-a 1y ago
  Education? Or more directly, socio-economics. The many of the subjects tested never had any experience with this kind of formal testing, had little to no education, and of course predictably failed on several abstract tasks. It might be that the very pattern of sitting down and intensely focusing on apparently meaningless problems isn't as innate as expected.
  - A4ET8a8uTh0_v2 1y ago
    Eh, I wish we could retire socioeconomics as a valid term. It can mean just about any factor and for it to be used it scientific publications and even normal discourse that goes beyond Facebook level discussion, feel a little counter-productive. What, exactly, did you mean though?
    - pona-a 1y ago
      I thought I was being clear. Access to education, which is a function of wealth, race segregation, and/or cultural expectations, or in other words, economic + social factors. For example, if a family encourages their child to work from the earliest allowed age at the expense of schooling, that's a manifestation of both economic and social pressures.
- qayxc 1y ago
  The brain has pretty high plasticity. A large host of factors contribute to the final outcome, from mental stimulation to training to overall health, stress (both physical and mental), and nutrition. It has been shown that IQ scores improve significantly just by taking them multiple times (training) [1]. They also vary if the tested person is sleep deprived, sick, or stressed. [1] https://pmc.ncbi.nlm.nih.gov/articles/PMC7709590 https://pmc.ncbi.nlm.nih.gov/articles/PMC7709590
  - nialse 1y ago
    You do have to consider that g is the amount of plasticity though, which is mainly genetic. A better way is to think of it is that genetics provides a potential capacity which may or may not be fulfilled. Training helps individuals to varying degrees.
    - matthewdgreen 1y ago
      That seems intuitive to me, but lots of other things in science seemed intuitive because I wanted to believe them. If the measured IQ difference in individuals can be overwhelmed by simple factors like “have I taken the test before”, we don’t really have a useful empirical measurement to say these things and we’re just stating our hopes and dreams.
      - nialse 1y ago
        The training effect in test-retest is dependent on g as well. It is intelligent to learn from past experiences. Measuring g is hard and taking shortcuts is tempting. A reasonable repeatable g factor test takes hours, and is too often replaced by a single test. There are ways around the test-retest issues but they are roads less travelled.
        thechao 1y ago
        My high school was right across from a branch of a university (UHD) where the PhD candidates developed IQ tests. We (the HS students) could take them for extra credit. My favorite example was a block-arranging test (there was a set of blocks & some pictures). Anyways, they printed the blocks "symmetrically"; once I figured that out, making the picture was limited only by how quickly I could move. (The test normally had you looking at all sides of the cube, repeatedly.) My "IQ" was well over 200 on that test. The candidate said that it was going to set their lab back bag years.
- gus_massa 1y ago
  Nutrition: just remove a few vitamins and watch the IQ drop like a stone. Even a "balanced" diet with 500kcal/day will be harmful. Education: in spite of the claims, a good education raise the IQ measurement. The test leak and school add similar tasks.
  - nialse 1y ago
    Counter point: does not nutrition and education help some people more than others? That’s the g factor which is mainly genetic.
    - gus_massa 1y ago
      >>> They then hypothesized a general factor, “g,” to explain this pattern. >> what's the point of all the intervention in the form of teaching/parenting styles and whatnot, if g factor is nature and immutable by large? What's the logic of the educators here? > does not nutrition and education help some people more than others? That’s the g factor which is mainly genetic. Yes, if you ignore or compensate everithing else, it's mainly genetic.
      - nialse 1y ago
        That is correct. The null hypothesis tested is: if you compensate for everything the result is the same for everyone, given that genetics have no effects on g. Hence, the null hypothesis is rejected. Thus, mainly genetic factors underlie the g factor.
        gus_massa 1y ago
        I think everyone is using a different definition of the g factor.
        nialse 1y ago
        One is certainly not, unless one is not well read. The g-factor is one of the most stable findings in psychology. It is well established and well defined.
- deleted 1y ago
  [deleted]
- hemabe 1y ago
  IQ is largely genetic, even if some people claim otherwise. The evidence for this is now overwhelming: even when different ethnic groups grow up in very similar conditions in the same country, the PISA (which correlates r=0.9 with IQ) scores measured vary greatly. For example, among second-generation children in Germany, there are significant differences in PISA scores. Polish children achieve similar or even better scores than German children. Turkish children, on the other hand, remain at the same poor level that their parents (the first generation of immigrants) achieved in the tests. Twin studies and studies of adopted children also leave no doubt that there is a very strong genetic component that determines IQ. Even Wikipedia assumes that heritability can be as high as 80%. Links https://en.wikipedia.org/wiki/Heritability_of_IQ https://en.wikipedia.org/wiki/Heritability_of_IQ https://www.welt.de/wirtschaft/article174706968/OECD-Studie-So-schwer-haben-es-Migranten-an-deutschen-Schulen.html https://www.welt.de/wirtschaft/article174706968/OECD-Studie-...
  - aredox 1y ago
    And it doesn't occur to you the parents may help their kids during their studies? You never went to your father of mother to ask them to explain a concept you struggled with in class? Now imagine your parents didn't get an education and couldn't help you. Where would you be now?
  - flir 1y ago
    https://en.wikipedia.org/wiki/Flynn_effect https://en.wikipedia.org/wiki/Flynn_effect
  - froh 1y ago
    especially Germany is a very poor example for this claim as school performance (PISA) in this country correlates with the parents academic background more than anything. if your parents aren't educated you can be intelligent AF and still will fail the German school system while you can be dumb as a brick but still make Abitur if your parents drill you through. in Germany. and Welt is a media source with a right conservative agenda pushing the genetics narrative.
    - robwwilliams 1y ago
- deleted 1y ago
  [deleted]
- flir 1y ago
  Consider genetics as a ceiling. An upper bound. Take the same child, give it an "ideal" upbringing or an abusive upbringing. You're going to get different IQ scores out of the adult. I believe you can see this in the Flynn Effect.
- robwwilliams 1y ago
  The simple answer that is usually right: “A god-awful complex mixture of genetic variation, stochastic variation during development, and innumerable environmental influences, all interacting in a big recursive hairball.” I hope that satisfies everyone ;-)
  - deleted 1y ago
    [deleted]
nialse 1y ago
Do note that The Bell Curve is not considered controversial in general. The part about race and genetics is. Also genes being the sole predictor of IQ is not an accurate description of the book’s premise.
- breakyerself 1y ago
  No the whole book is controversial. It's a political argument for dismantling the welfare state disguised as a review of science. They laundered a bunch of work by racial eugenicists along with a bunch of other junk science methodology. https://youtu.be/UBc7qBS1Ujo?si=bzVMwGU4XjPrk4sr https://youtu.be/UBc7qBS1Ujo?si=bzVMwGU4XjPrk4sr
  - nialse 1y ago
    I hear you are invested in this line of thought, and that is okay. I just don’t agree with the analysis, and not with the labeling.
    - breakyerself 1y ago
      It doesn't rely on work by Eugenicists?
      - nialse 1y ago
        Fortunately, science does not rely on the character of its purveyors but on the quality of the evidence.
        breakyerself 1y ago
        The quality of the evidence wasn't any better than the character of the purveyors. You're an apologist for bullshit.
  - machomaster 1y ago
    Calling something "controversial" is a total non-argument. The book's science about IQ is solid. In actuality, the content of the book was simply a collection of mainstream scientific consensus ideas at that time, without specific controversial add-ons. It's only after the book was published, the book unexpectedly was attacked by proto-woke people.
alphazard 1y ago
This is misleading. Anyone who wants to learn about IQ should Google it. It's the most replicated finding in psychology, and any questions you have about twins or groups with similar or different genes have probably been investigated. There is a lot of noise online in the form of commentary about IQ, so it's important to look at actual data if you are skeptical/curious.
- robwwilliams 1y ago
  Not sure what you mean precisely. Yes lots if work in IQ, but that does not mean there is a grand consensus. I am a geneticist who studies cognitive function. The single most common misunderstanding about estimates of heritability is that a high heritability implies full genetic causation without potential malleability. That is total wrong. Heritability is always measured in the context of Environment X. If you change to Environment Y or Z then the heritability will often change greatly.
  - cakealert 1y ago
    Unfortunately most of the malleability is non-systematic (can't be engineered by a third party). Which means it's caused by the nonlinear dynamics between the genes and environment.
  - hirvi74 1y ago
    As a geneticist who studies cognitive function, if you get a moment, do you mind reading this blog [1] and stating if you think it's factually correct or not? My genes are too poor, and thus, my IQ is likely too low for me to be certain I can trust my own opinions on the matter. [1] http://bactra.org/weblog/520.html http://bactra.org/weblog/520.html
  - EnPissant 1y ago
    > Heritability is always measured in the context of Environment X. If you change to Environment Y or Z then the heritability will often change greatly. That's not a very meaningful statement. If you took two twins and severely malnourished one of them it would not be useful to say: "See! IQ is mostly environmental!". You have to assume some kind of baseline environment that nearly everyone will share, and that can be full-filled just by the virtue of growing up in a country like America. Otherwise, you are just concerning yourself with insignificant outliers. Here is a twin study that places the heritability at ~80%: https://www.cambridge.org/core/journals/twin-research-and-human-genetics/article/wilson-effect-the-increase-in-heritability-of-iq-with-age/FF406CC4CF286D78AF72C9E7EF9B5E3F https://www.cambridge.org/core/journals/twin-research-and-hu...
hemabe 1y ago
And yet, in the US, the first start-ups are offering the possibility of testing embryos for their IQ. https://www.theguardian.com/science/2024/oct/18/us-startup-charging-couples-to-screen-embryos-for-iq https://www.theguardian.com/science/2024/oct/18/us-startup-c...
- breakyerself 1y ago
  So if a start up makes a claim it must be real? Theranos investors would like a word.
- torginus 1y ago
  > they claimed selecting the “smartest” of 10 embryos would lead to an average IQ gain of more than six points Ethics aside this sounds like BS - how do you measure the IQ of someone against someone else who was never born?
  - nradov 1y ago
    It's at least mostly BS. Researchers have found certain genes which have a weak statistical correlation with high IQ but the mechanism of action is unknown. And it's not an additive thing: the interactions and relationships between individual genes must play some role but that has barely been studied at all. There's no guarantee that an embryo with those genes will grow up to be intelligent, or that they won't have other problems. But there's enough "dumb money" in Silicon Valley to provide a customer base of insecure suckers for these startups. https://www.wsj.com/us-news/silicon-valley-high-iq-children-764234f8?st=7D1Dp1&reflink=desktopwebshare_permalink https://www.wsj.com/us-news/silicon-valley-high-iq-children-...
    - whatshisface 1y ago
      One of the dark comedies playing out in the world right now is that if random physical features are correlated with IQ testing due to co-heritability, users of IVF selection will be imprinting them on their own kids.
  - Spooky23 1y ago
BoingBoomTschak 1y ago
How much of that controversy is manufactured, though? https://en.wikipedia.org/wiki/The_IQ_Controversy,_the_Media_and_Public_Policy https://en.wikipedia.org/wiki/The_IQ_Controversy,_the_Media_... (if even Wikipedia can't drag this through the mud...)
- breakyerself 1y ago
  It's well deserved. The bell curve isnt a good work of science.
A4ET8a8uTh0_v2 1y ago
It is not controversial at all. It was deemed inappropriate due the amount of 'wrongthink' it causes. We can argue about what followed and whether its claims have been nullified, but given how much conversations started with it, I sincerely doubt the argument that it should not be the introduction is reasonable. In a sense, it is the source of the debate.
holbrad 1y ago
> has been completely and undeniably refuted by science in the thirty years since it's publication. This is literally the exact opposite.
- aredox 1y ago
  This is exactly the case. The only thing IQ tests measure is the ability to score well at an IQ test. Just look at what MENSA has produced: buffoons.
fortran77 1y ago
I've read the book. I says that aspects of IQ can be heritable, but doesn't ever say "genetics are the main predictor of IQ". Quoting direcly from the book: "It seems highly likely to us that both genes and the environment have something to do with IQ differences” and the book states that "the exact contribution of genes versus environment is unknown."

brabel 1y ago

Really? If not genetics then what is it? Just random??

smokel 1y ago
If it isn't nature, then it probably is nurture. Averaged over the entire population, that is indeed mostly random.
mdp2021 1y ago
Personal development. It's a "subtle" skill. You train it (though maybe less directly than other skills).
pona-a 1y ago
Education? Or more directly, socio-economics. The many of the subjects tested never had any experience with this kind of formal testing, had little to no education, and of course predictably failed on several abstract tasks. It might be that the very pattern of sitting down and intensely focusing on apparently meaningless problems isn't as innate as expected.
- A4ET8a8uTh0_v2 1y ago
  Eh, I wish we could retire socioeconomics as a valid term. It can mean just about any factor and for it to be used it scientific publications and even normal discourse that goes beyond Facebook level discussion, feel a little counter-productive. What, exactly, did you mean though?
  - pona-a 1y ago
    I thought I was being clear. Access to education, which is a function of wealth, race segregation, and/or cultural expectations, or in other words, economic + social factors. For example, if a family encourages their child to work from the earliest allowed age at the expense of schooling, that's a manifestation of both economic and social pressures.
qayxc 1y ago
The brain has pretty high plasticity. A large host of factors contribute to the final outcome, from mental stimulation to training to overall health, stress (both physical and mental), and nutrition. It has been shown that IQ scores improve significantly just by taking them multiple times (training) [1]. They also vary if the tested person is sleep deprived, sick, or stressed. [1] https://pmc.ncbi.nlm.nih.gov/articles/PMC7709590 https://pmc.ncbi.nlm.nih.gov/articles/PMC7709590
- nialse 1y ago
  You do have to consider that g is the amount of plasticity though, which is mainly genetic. A better way is to think of it is that genetics provides a potential capacity which may or may not be fulfilled. Training helps individuals to varying degrees.
  - matthewdgreen 1y ago
    That seems intuitive to me, but lots of other things in science seemed intuitive because I wanted to believe them. If the measured IQ difference in individuals can be overwhelmed by simple factors like “have I taken the test before”, we don’t really have a useful empirical measurement to say these things and we’re just stating our hopes and dreams.
    - nialse 1y ago
      The training effect in test-retest is dependent on g as well. It is intelligent to learn from past experiences. Measuring g is hard and taking shortcuts is tempting. A reasonable repeatable g factor test takes hours, and is too often replaced by a single test. There are ways around the test-retest issues but they are roads less travelled.
      - thechao 1y ago
        My high school was right across from a branch of a university (UHD) where the PhD candidates developed IQ tests. We (the HS students) could take them for extra credit. My favorite example was a block-arranging test (there was a set of blocks & some pictures). Anyways, they printed the blocks "symmetrically"; once I figured that out, making the picture was limited only by how quickly I could move. (The test normally had you looking at all sides of the cube, repeatedly.) My "IQ" was well over 200 on that test. The candidate said that it was going to set their lab back bag years.
gus_massa 1y ago
Nutrition: just remove a few vitamins and watch the IQ drop like a stone. Even a "balanced" diet with 500kcal/day will be harmful. Education: in spite of the claims, a good education raise the IQ measurement. The test leak and school add similar tasks.
- nialse 1y ago
  Counter point: does not nutrition and education help some people more than others? That’s the g factor which is mainly genetic.
  - gus_massa 1y ago
    >>> They then hypothesized a general factor, “g,” to explain this pattern. >> what's the point of all the intervention in the form of teaching/parenting styles and whatnot, if g factor is nature and immutable by large? What's the logic of the educators here? > does not nutrition and education help some people more than others? That’s the g factor which is mainly genetic. Yes, if you ignore or compensate everithing else, it's mainly genetic.
    - nialse 1y ago
      That is correct. The null hypothesis tested is: if you compensate for everything the result is the same for everyone, given that genetics have no effects on g. Hence, the null hypothesis is rejected. Thus, mainly genetic factors underlie the g factor.
      - gus_massa 1y ago
        I think everyone is using a different definition of the g factor.
        nialse 1y ago
        One is certainly not, unless one is not well read. The g-factor is one of the most stable findings in psychology. It is well established and well defined.
deleted 1y ago
[deleted]
hemabe 1y ago
IQ is largely genetic, even if some people claim otherwise. The evidence for this is now overwhelming: even when different ethnic groups grow up in very similar conditions in the same country, the PISA (which correlates r=0.9 with IQ) scores measured vary greatly. For example, among second-generation children in Germany, there are significant differences in PISA scores. Polish children achieve similar or even better scores than German children. Turkish children, on the other hand, remain at the same poor level that their parents (the first generation of immigrants) achieved in the tests. Twin studies and studies of adopted children also leave no doubt that there is a very strong genetic component that determines IQ. Even Wikipedia assumes that heritability can be as high as 80%. Links https://en.wikipedia.org/wiki/Heritability_of_IQ https://en.wikipedia.org/wiki/Heritability_of_IQ https://www.welt.de/wirtschaft/article174706968/OECD-Studie-So-schwer-haben-es-Migranten-an-deutschen-Schulen.html https://www.welt.de/wirtschaft/article174706968/OECD-Studie-...
- aredox 1y ago
  And it doesn't occur to you the parents may help their kids during their studies? You never went to your father of mother to ask them to explain a concept you struggled with in class? Now imagine your parents didn't get an education and couldn't help you. Where would you be now?
- flir 1y ago
  https://en.wikipedia.org/wiki/Flynn_effect https://en.wikipedia.org/wiki/Flynn_effect
- froh 1y ago
  especially Germany is a very poor example for this claim as school performance (PISA) in this country correlates with the parents academic background more than anything. if your parents aren't educated you can be intelligent AF and still will fail the German school system while you can be dumb as a brick but still make Abitur if your parents drill you through. in Germany. and Welt is a media source with a right conservative agenda pushing the genetics narrative.
  - robwwilliams 1y ago
deleted 1y ago
[deleted]
flir 1y ago
Consider genetics as a ceiling. An upper bound. Take the same child, give it an "ideal" upbringing or an abusive upbringing. You're going to get different IQ scores out of the adult. I believe you can see this in the Flynn Effect.
robwwilliams 1y ago
The simple answer that is usually right: “A god-awful complex mixture of genetic variation, stochastic variation during development, and innumerable environmental influences, all interacting in a big recursive hairball.” I hope that satisfies everyone ;-)
- deleted 1y ago
  [deleted]

nialse 1y ago

Do note that The Bell Curve is not considered controversial in general. The part about race and genetics is. Also genes being the sole predictor of IQ is not an accurate description of the book’s premise.

breakyerself 1y ago
No the whole book is controversial. It's a political argument for dismantling the welfare state disguised as a review of science. They laundered a bunch of work by racial eugenicists along with a bunch of other junk science methodology. https://youtu.be/UBc7qBS1Ujo?si=bzVMwGU4XjPrk4sr https://youtu.be/UBc7qBS1Ujo?si=bzVMwGU4XjPrk4sr
- nialse 1y ago
  I hear you are invested in this line of thought, and that is okay. I just don’t agree with the analysis, and not with the labeling.
  - breakyerself 1y ago
    It doesn't rely on work by Eugenicists?
    - nialse 1y ago
      Fortunately, science does not rely on the character of its purveyors but on the quality of the evidence.
      - breakyerself 1y ago
        The quality of the evidence wasn't any better than the character of the purveyors. You're an apologist for bullshit.
- machomaster 1y ago
  Calling something "controversial" is a total non-argument. The book's science about IQ is solid. In actuality, the content of the book was simply a collection of mainstream scientific consensus ideas at that time, without specific controversial add-ons. It's only after the book was published, the book unexpectedly was attacked by proto-woke people.

alphazard 1y ago

This is misleading. Anyone who wants to learn about IQ should Google it. It's the most replicated finding in psychology, and any questions you have about twins or groups with similar or different genes have probably been investigated. There is a lot of noise online in the form of commentary about IQ, so it's important to look at actual data if you are skeptical/curious.

robwwilliams 1y ago
Not sure what you mean precisely. Yes lots if work in IQ, but that does not mean there is a grand consensus. I am a geneticist who studies cognitive function. The single most common misunderstanding about estimates of heritability is that a high heritability implies full genetic causation without potential malleability. That is total wrong. Heritability is always measured in the context of Environment X. If you change to Environment Y or Z then the heritability will often change greatly.
- cakealert 1y ago
  Unfortunately most of the malleability is non-systematic (can't be engineered by a third party). Which means it's caused by the nonlinear dynamics between the genes and environment.
- hirvi74 1y ago
  As a geneticist who studies cognitive function, if you get a moment, do you mind reading this blog [1] and stating if you think it's factually correct or not? My genes are too poor, and thus, my IQ is likely too low for me to be certain I can trust my own opinions on the matter. [1] http://bactra.org/weblog/520.html http://bactra.org/weblog/520.html
- EnPissant 1y ago
  > Heritability is always measured in the context of Environment X. If you change to Environment Y or Z then the heritability will often change greatly. That's not a very meaningful statement. If you took two twins and severely malnourished one of them it would not be useful to say: "See! IQ is mostly environmental!". You have to assume some kind of baseline environment that nearly everyone will share, and that can be full-filled just by the virtue of growing up in a country like America. Otherwise, you are just concerning yourself with insignificant outliers. Here is a twin study that places the heritability at ~80%: https://www.cambridge.org/core/journals/twin-research-and-human-genetics/article/wilson-effect-the-increase-in-heritability-of-iq-with-age/FF406CC4CF286D78AF72C9E7EF9B5E3F https://www.cambridge.org/core/journals/twin-research-and-hu...

hemabe 1y ago

And yet, in the US, the first start-ups are offering the possibility of testing embryos for their IQ. https://www.theguardian.com/science/2024/oct/18/us-startup-charging-couples-to-screen-embryos-for-iq https://www.theguardian.com/science/2024/oct/18/us-startup-c...

breakyerself 1y ago
So if a start up makes a claim it must be real? Theranos investors would like a word.
torginus 1y ago
> they claimed selecting the “smartest” of 10 embryos would lead to an average IQ gain of more than six points Ethics aside this sounds like BS - how do you measure the IQ of someone against someone else who was never born?
- nradov 1y ago
  It's at least mostly BS. Researchers have found certain genes which have a weak statistical correlation with high IQ but the mechanism of action is unknown. And it's not an additive thing: the interactions and relationships between individual genes must play some role but that has barely been studied at all. There's no guarantee that an embryo with those genes will grow up to be intelligent, or that they won't have other problems. But there's enough "dumb money" in Silicon Valley to provide a customer base of insecure suckers for these startups. https://www.wsj.com/us-news/silicon-valley-high-iq-children-764234f8?st=7D1Dp1&reflink=desktopwebshare_permalink https://www.wsj.com/us-news/silicon-valley-high-iq-children-...
  - whatshisface 1y ago
    One of the dark comedies playing out in the world right now is that if random physical features are correlated with IQ testing due to co-heritability, users of IVF selection will be imprinting them on their own kids.
- Spooky23 1y ago

BoingBoomTschak 1y ago

How much of that controversy is manufactured, though? https://en.wikipedia.org/wiki/The_IQ_Controversy,_the_Media_and_Public_Policy https://en.wikipedia.org/wiki/The_IQ_Controversy,_the_Media_... (if even Wikipedia can't drag this through the mud...)

breakyerself 1y ago
It's well deserved. The bell curve isnt a good work of science.

A4ET8a8uTh0_v2 1y ago

It is not controversial at all. It was deemed inappropriate due the amount of 'wrongthink' it causes. We can argue about what followed and whether its claims have been nullified, but given how much conversations started with it, I sincerely doubt the argument that it should not be the introduction is reasonable. In a sense, it is the source of the debate.

holbrad 1y ago

> has been completely and undeniably refuted by science in the thirty years since it's publication. This is literally the exact opposite.

aredox 1y ago
This is exactly the case. The only thing IQ tests measure is the ability to score well at an IQ test. Just look at what MENSA has produced: buffoons.

fortran77 1y ago

I've read the book. I says that aspects of IQ can be heritable, but doesn't ever say "genetics are the main predictor of IQ". Quoting direcly from the book: "It seems highly likely to us that both genes and the environment have something to do with IQ differences” and the book states that "the exact contribution of genes versus environment is unknown."