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It's also significantly genetically determined (twin studies) so in this case I meant genetic heritability. Also for some reason people seem to think I'm makin

It's also significantly genetically determined (twin studies) so in this case I meant genetic heritability. Also for some reason people seem to think I'm making a comment about high IQ and elitism. I think low IQ is far more important for poverty discussion. Like sub 80 IQ is a significant percentage of population while being close to or having a mental disability. Sub 100 kind of makes it hard to have a well paying job in today's economy. And not only is genetic factor big here but also having low IQ/poor parents means your environment will likely have a negative impact on your cognitive development.

tptacek 2y ago
No, that's not how this works. You can't just say "twin study" and dispel the environment(s), and, in fact, GWAS is pushing things in the opposite direction (people will argue by how much, but the direction is clear).
- rafaelmn 2y ago
  Split twins strongly backs genetic component, and heritability is also significant. There's nothing to dispell, environment does seem to be a factor in negative direction, so that's undoubtedly a big factor as well. But low IQ people having low IQ children is going to explain a lot of it - no need to be a "social darwinists" to believe that.
  - tptacek 2y ago
    Split twins does the opposite: separated twins IQ-test outcomes track the SES of the families they go to. But "twin studies" is science at the level of "The Bell Curve", which is 30 years old. At this point, you kind of have to want IQ to be genetically determined (in any meaningful amount) to believe it is.
    - rafaelmn 2y ago
      > Split twins does the opposite: separated twins IQ-test outcomes track the SES of the families they go to. Consider me convinced if you can source this - I'm not finding anything but opposite - that they strongly correlate the older they get (IQ test).
      - tptacek 2y ago
        Read Turkheimer.
        rafaelmn 2y ago
        Something more specific ? Couldn't find anything directly saying what you're claiming here. I was interested if my info was out of date so I found this https://www.sciencedirect.com/science/article/pii/S0191886924002113 https://www.sciencedirect.com/science/article/pii/S019188692... which basically again confirms genetic IQ factor in adults is major. Separated twins correlate, siblings corelate less and virtual twins (same age unrelated siblings) corelate way less. Anyway I'm no expert on this, but I've heard this view from multiple credible sources and the more I dig in the more it seems supported.
        tptacek 2y ago
        What were those credible sources?
        rafaelmn 2y ago
        First one that comes to mind is The Blank Slate from Pinker, but I have read that like 15 years ago. But it did shape my view on the subject and I have seen this topic come up many times since. I don't remember anyone disputing strong genetic component of IQ, other than people uncomfortable with implications. And I am not even that interested in the social implications, but more practical issues like IQ improvement (basically 0 impact from what I have seen other than being physically fit/exercising), implications on parenting (you cant imprint your desired outcomes on your children and need to play to their innate interests and strengths/weaknesses), etc.
    - milesrout 2y ago
      The Bell Curve is a great book that is unfortunately maligned by people that dislike what it says but all too often have no actual arguments against what it says. Separated twin studies show conclusively that IQ is (partially) genetically determined as does, yknow, all common experience and intuition.
      - tptacek 2y ago
        Can you name three people who practice in this field (Turkheimer, who I named upthread, is a harsh critic of the book and a giant in this field) who agree with your take here?
sethev 2y ago
> whether or not you wear lipstick has high heritability. Think about this example. The genetic factor here is massive, much higher than anyone is claiming for IQ. Can you imagine how hopelessly lost you would be if your analysis of lipstick distribution in the population focused on its heritability and link to genetics?
- tptacek 2y ago
  An even bigger issue you immediately run into in these conversations: someone will say "I don't mean heritability that way, I mean genetic heritability". Which, whatever, except: now you've discarded all the science. The papers you'd draw these numbers from are referring to heritability in its technical sense, not in some message board sense.
  - sethev 2y ago
    Yes. I mean, either you're talking about statistical properties of a population or you're talking about something else. These discussions usually devolve into "something else" almost immediately.
  - rafaelmn 2y ago
    I mean I still fail to see how comparing these three scenarios - genetic twins separated at birth - genetic siblings raised in same household - genetically unrelated same age siblings adopted in the same household are teasing out anything but an underlying genetic component and reproducing in studies
    - tptacek 2y ago
      You can have intuitions about any of these issues, but you can't use heritability research as evidence for them without understanding the technical meaning of "heritability". That's all that's being said here.

tptacek 2y ago

No, that's not how this works. You can't just say "twin study" and dispel the environment(s), and, in fact, GWAS is pushing things in the opposite direction (people will argue by how much, but the direction is clear).

rafaelmn 2y ago
Split twins strongly backs genetic component, and heritability is also significant. There's nothing to dispell, environment does seem to be a factor in negative direction, so that's undoubtedly a big factor as well. But low IQ people having low IQ children is going to explain a lot of it - no need to be a "social darwinists" to believe that.
- tptacek 2y ago
  Split twins does the opposite: separated twins IQ-test outcomes track the SES of the families they go to. But "twin studies" is science at the level of "The Bell Curve", which is 30 years old. At this point, you kind of have to want IQ to be genetically determined (in any meaningful amount) to believe it is.
  - rafaelmn 2y ago
    > Split twins does the opposite: separated twins IQ-test outcomes track the SES of the families they go to. Consider me convinced if you can source this - I'm not finding anything but opposite - that they strongly correlate the older they get (IQ test).
    - tptacek 2y ago
      Read Turkheimer.
      - rafaelmn 2y ago
        Something more specific ? Couldn't find anything directly saying what you're claiming here. I was interested if my info was out of date so I found this https://www.sciencedirect.com/science/article/pii/S0191886924002113 https://www.sciencedirect.com/science/article/pii/S019188692... which basically again confirms genetic IQ factor in adults is major. Separated twins correlate, siblings corelate less and virtual twins (same age unrelated siblings) corelate way less. Anyway I'm no expert on this, but I've heard this view from multiple credible sources and the more I dig in the more it seems supported.
        tptacek 2y ago
        What were those credible sources?
        rafaelmn 2y ago
        First one that comes to mind is The Blank Slate from Pinker, but I have read that like 15 years ago. But it did shape my view on the subject and I have seen this topic come up many times since. I don't remember anyone disputing strong genetic component of IQ, other than people uncomfortable with implications. And I am not even that interested in the social implications, but more practical issues like IQ improvement (basically 0 impact from what I have seen other than being physically fit/exercising), implications on parenting (you cant imprint your desired outcomes on your children and need to play to their innate interests and strengths/weaknesses), etc.
  - milesrout 2y ago
    The Bell Curve is a great book that is unfortunately maligned by people that dislike what it says but all too often have no actual arguments against what it says. Separated twin studies show conclusively that IQ is (partially) genetically determined as does, yknow, all common experience and intuition.
    - tptacek 2y ago
      Can you name three people who practice in this field (Turkheimer, who I named upthread, is a harsh critic of the book and a giant in this field) who agree with your take here?

sethev 2y ago

> whether or not you wear lipstick has high heritability. Think about this example. The genetic factor here is massive, much higher than anyone is claiming for IQ. Can you imagine how hopelessly lost you would be if your analysis of lipstick distribution in the population focused on its heritability and link to genetics?

tptacek 2y ago
An even bigger issue you immediately run into in these conversations: someone will say "I don't mean heritability that way, I mean genetic heritability". Which, whatever, except: now you've discarded all the science. The papers you'd draw these numbers from are referring to heritability in its technical sense, not in some message board sense.
- sethev 2y ago
  Yes. I mean, either you're talking about statistical properties of a population or you're talking about something else. These discussions usually devolve into "something else" almost immediately.
- rafaelmn 2y ago
  I mean I still fail to see how comparing these three scenarios - genetic twins separated at birth - genetic siblings raised in same household - genetically unrelated same age siblings adopted in the same household are teasing out anything but an underlying genetic component and reproducing in studies
  - tptacek 2y ago
    You can have intuitions about any of these issues, but you can't use heritability research as evidence for them without understanding the technical meaning of "heritability". That's all that's being said here.