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Genes don't even have to boost intelligence for kids from smart parents to be more likely to be intelligent. Just think of a kid adopted out of the nursery by

Genes don't even have to boost intelligence for kids from smart parents to be more likely to be intelligent. Just think of a kid adopted out of the nursery by two smart parents. Is that kid: A) more likely to score higher on tests, B) more likely to score lower on tests, or C) exactly as likely to score high/low on tests no matter who his adoptive parents are?

cjbgkagh 4y ago
Unfortunately intelligence is mostly genetic, look it up... Edit: This is my opinion on what I consider a fact based on a fair bit of research and first hand observation. People are free to disagree with this but if they've made it to this point still holding that opinion then I think it's unlikely anything I could say would change their minds.
- dwringer 4y ago
  Are you suggesting, then, that the answer is C? I would hypothesize A is more likely, even assuming intelligence is genetic. Thus, my only point was there's a confounding variable if we try to use the relative tested levels of intelligence between parents an children as a basis to say whether intelligence is genetic. That's not to say there aren't potentially ways around that by designing studies carefully.
- bee_rider 4y ago
  If you want to make a claim, source it. Given the difficulty of defining an objective measure for intelligence and the confounding factors of upbringing, I think it is almost impossible to find a good source on this sort of thing. Why should we go on a snipe hunt to prove your point?
  - mlyle 4y ago
    > difficulty of defining an objective measure for intelligence IQ is not a perfect metric, but it is a decent predictor of many outcomes. > the confounding factors of upbringing This is why you do twin studies and studies using adoption as a control. We have quite a wealth of them. A good critical review of the evidence on both sides is here: https://humanvarietiesdotorg.files.wordpress.com/2013/05/the-effects-of-shared-environment-on-adult-intelligence-a-critical-review-of-adoption-twin-and-mza-studies.pdf https://humanvarietiesdotorg.files.wordpress.com/2013/05/the... * Identical twins have a much higher correlation coefficient of intelligence than fraternal twins (table 5). * Identical twins raised apart have a correlation coefficient for intelligence of around .73 (MZA studies). * Correlation coefficients of IQs of biologically unrelated siblings raised in the same adoptive environment are approximately 0. There are obvious confounds the paper mentions: * Fraternal twins may not have identical environments. * Adoptive environments may not represent typical parenting environments. * Some of these studies have had poor controls and practices. * Distribution of results from studies looks bimodal which indicates something weird is going on. Still, even if you take the most critical view I think you have to accept that there is still substantial heritability of intelligence. These results cannot be convincingly explained any other way.
- deleted 4y ago
  [deleted]
- dwringer 4y ago
  > Edit: This is my opinion on what I consider a fact based on a fair bit of research and first hand observation. People are free to disagree with this You replied to my comment of "genes don't even have to boost intelligence for kids from smart parents to be more likely to be intelligent" with "Unfortunately intelligence is mostly genetic, look it up..." I'm not sure why you used the word "unfortunately" or what you want me to look up since you didn't even appear to be responding to what I wrote. > but if they've made it to this point still holding that opinion[...] I'm confused as to what this is intended to mean. > [...]then I think it's unlikely anything I could say would change their minds. How can you know to what extent anyone reading this has made up their mind about anything?
  - cjbgkagh 4y ago
    This seems like sealioning to me and I have no incentive to engage.
gwern 4y ago
> Just think of a kid adopted out of the nursery by two smart parents. Is that kid: A) more likely to score higher on tests, B) more likely to score lower on tests, or C) exactly as likely to score high/low on tests no matter who his adoptive parents are? Approximately C. See IQ adoption studies like https://www.gwern.net/docs/iq/2021-willoughby.pdf#page=6 https://www.gwern.net/docs/iq/2021-willoughby.pdf#page=6 for the scatterplot for adoptive parental IQ vs adoptee.
- dwringer 4y ago
  It is quite possible that the standards for adoption are such that only couples able to raise children in a nurturing environment capable of fostering intellectual growth are typically allowed to adopt and raise children. They are not an accurate cross-section of all potential parents by any means. I am imagining if any couple could adopt; taking the same kid (which of course we cannot do) and having them raised by a couple of college professors vs. a couple of meth addicts living in a drug den - I would be absolutely stunned if there were no difference in what kind of test scores the kid would get growing up.
  - PeterisP 4y ago
    > taking the same kid (which of course we cannot do) There were a bunch of studies on identical twins who were adopted in different families, so it can be tested. I think they showed the same thing (kids parents more important than adoptive parents) but I'm not certain and can't quickly find the studies to verify.
    - dwringer 4y ago
      Twin studies are a good way to get another angle on this. Here, unfortunately that doesn't get around the confounding factor that only parents deemed suitable candidates by adoption agencies are able to adopt and raise children, so they are not an accurate cross section of all possible parents. I don't dispute that there may be a threshhold at which some innate traits take over (or fail to do so) from the benefits of a nurturing environment (which may have diminishing returns past a certain point).

cjbgkagh 4y ago

Unfortunately intelligence is mostly genetic, look it up... Edit: This is my opinion on what I consider a fact based on a fair bit of research and first hand observation. People are free to disagree with this but if they've made it to this point still holding that opinion then I think it's unlikely anything I could say would change their minds.

dwringer 4y ago
Are you suggesting, then, that the answer is C? I would hypothesize A is more likely, even assuming intelligence is genetic. Thus, my only point was there's a confounding variable if we try to use the relative tested levels of intelligence between parents an children as a basis to say whether intelligence is genetic. That's not to say there aren't potentially ways around that by designing studies carefully.
bee_rider 4y ago
If you want to make a claim, source it. Given the difficulty of defining an objective measure for intelligence and the confounding factors of upbringing, I think it is almost impossible to find a good source on this sort of thing. Why should we go on a snipe hunt to prove your point?
- mlyle 4y ago
  > difficulty of defining an objective measure for intelligence IQ is not a perfect metric, but it is a decent predictor of many outcomes. > the confounding factors of upbringing This is why you do twin studies and studies using adoption as a control. We have quite a wealth of them. A good critical review of the evidence on both sides is here: https://humanvarietiesdotorg.files.wordpress.com/2013/05/the-effects-of-shared-environment-on-adult-intelligence-a-critical-review-of-adoption-twin-and-mza-studies.pdf https://humanvarietiesdotorg.files.wordpress.com/2013/05/the... * Identical twins have a much higher correlation coefficient of intelligence than fraternal twins (table 5). * Identical twins raised apart have a correlation coefficient for intelligence of around .73 (MZA studies). * Correlation coefficients of IQs of biologically unrelated siblings raised in the same adoptive environment are approximately 0. There are obvious confounds the paper mentions: * Fraternal twins may not have identical environments. * Adoptive environments may not represent typical parenting environments. * Some of these studies have had poor controls and practices. * Distribution of results from studies looks bimodal which indicates something weird is going on. Still, even if you take the most critical view I think you have to accept that there is still substantial heritability of intelligence. These results cannot be convincingly explained any other way.
deleted 4y ago
[deleted]
dwringer 4y ago
> Edit: This is my opinion on what I consider a fact based on a fair bit of research and first hand observation. People are free to disagree with this You replied to my comment of "genes don't even have to boost intelligence for kids from smart parents to be more likely to be intelligent" with "Unfortunately intelligence is mostly genetic, look it up..." I'm not sure why you used the word "unfortunately" or what you want me to look up since you didn't even appear to be responding to what I wrote. > but if they've made it to this point still holding that opinion[...] I'm confused as to what this is intended to mean. > [...]then I think it's unlikely anything I could say would change their minds. How can you know to what extent anyone reading this has made up their mind about anything?
- cjbgkagh 4y ago
  This seems like sealioning to me and I have no incentive to engage.

gwern 4y ago

> Just think of a kid adopted out of the nursery by two smart parents. Is that kid: A) more likely to score higher on tests, B) more likely to score lower on tests, or C) exactly as likely to score high/low on tests no matter who his adoptive parents are? Approximately C. See IQ adoption studies like https://www.gwern.net/docs/iq/2021-willoughby.pdf#page=6 https://www.gwern.net/docs/iq/2021-willoughby.pdf#page=6 for the scatterplot for adoptive parental IQ vs adoptee.

dwringer 4y ago
It is quite possible that the standards for adoption are such that only couples able to raise children in a nurturing environment capable of fostering intellectual growth are typically allowed to adopt and raise children. They are not an accurate cross-section of all potential parents by any means. I am imagining if any couple could adopt; taking the same kid (which of course we cannot do) and having them raised by a couple of college professors vs. a couple of meth addicts living in a drug den - I would be absolutely stunned if there were no difference in what kind of test scores the kid would get growing up.
- PeterisP 4y ago
  > taking the same kid (which of course we cannot do) There were a bunch of studies on identical twins who were adopted in different families, so it can be tested. I think they showed the same thing (kids parents more important than adoptive parents) but I'm not certain and can't quickly find the studies to verify.
  - dwringer 4y ago
    Twin studies are a good way to get another angle on this. Here, unfortunately that doesn't get around the confounding factor that only parents deemed suitable candidates by adoption agencies are able to adopt and raise children, so they are not an accurate cross section of all possible parents. I don't dispute that there may be a threshhold at which some innate traits take over (or fail to do so) from the benefits of a nurturing environment (which may have diminishing returns past a certain point).