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I've never heard a number as high as 70%. Where does that come from? Otherwise: any idea how intelligence was operationalized? I also think we can only accept

by tgv 5y ago

I've never heard a number as high as 70%. Where does that come from? Otherwise: any idea how intelligence was operationalized? I also think we can only accept that we're born different, but human. If we should aspire to anything, it should be to make life good for every individual, taking their capacities into account, not to give everyone an academic degree.

NoImmatureAdHom 5y ago
Here's a relatively recent study: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4270739/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4270739/ I agree with your sentiment in the second paragraph. Human gets a little fuzzy, though...I think you really mean to point at personhood. There are humans who definitely aren't people, like those born without brains. And with the computers our grandkids will install--oh my! I'll cross that bridge when I get to it.
mewpmewp2 5y ago
The percentage without context does not give any actual information. E.g. one could argue that environment affects 99 percent of intelligence as for example if someone dies due to environment there's no intelligence at all. So there must be some poor environment A and good environment B, and some poor genes A and good genes B that a comparison must be made between to understand exactly what this percentage means and of course there must be a definition of intelligence and a way to measure it.
- NoImmatureAdHom 5y ago
  Thanks for asking, I should've explained. The percentage here is percent of variance (https://en.wikipedia.org/wiki/Variance https://en.wikipedia.org/wiki/Variance). What it means, basically, is the extent to which you can predict a child's intelligence just knowing the parents' intelligence--not assuming the child was raised by those parents. In your second paragraph, you've actually hit on one of the apologetic clichés that's popular now. People will say, "Yes, 70-80% of variance...GIVEN OUR CURRENT ENVIRONMENT". And they will act as if they've said something profound. Yes, that's true, and we don't know about the heritability of intelligence in environments that don't exist...but we can make really good guesses. Further, from a public policy perspective, we've got to work in the environment that we've got. And in that environment, the number is 70-80%.
  - Ma8ee 5y ago
    No, from a public policy perspective, the important question is what environment can we create that benefit as many people as possible. The current environment, from prenatal care to availability, cost and quality of higher education is something that is created by public policy. It is certainly not anything given.
    - xyzzyz 5y ago
      > No, from a public policy perspective, the important question is what environment can we create that benefit as many people as possible. The problem is that since there already is substantial variance in environment that different people experience today, but nevertheless the amount of variance explained by shared environment is very, very low, this means that if we want to increase intelligence using environmental interventions, you can’t designate some environment that some (eg. well off people) already experience, and get everyone into that environment, because it simply won’t work. If it did, it would already show in the amount of variance explained by environment. Instead, what you need to do is to intervene by putting people in environments very few if any people today experience. This is the only approach that can work, as it can overcome the low amount of variance explained by environment. Suffice to say, nobody yet figured out what those unusual environments actually would be like, as you can’t simply copy whatever well off or genius people grow up like. If you do come up with something, it might end up being a hard sale too, given that this will be necessarily stranger than what people normally expect. But, if it works, you’ll improve the world massively and make history. Chances are against you though, as millions of people in the education industry worldwide have already tried almost anything you could come up with, and nothing really works.
    - tgv 5y ago
      > what environment can we create that benefit as many people as possible That can't be researched (effectively). Policies affect the current situation, not the desired one.
      - Ma8ee 5y ago
        You create the desired situation by affecting the current situation.
xyzzyz 5y ago
70% is actually on the low side of today’s results. Observed heritability is lower in early childhood (meaning the amount of variance in intelligence among children explained by genes is “only” 20%-50%, “only” in quotes because it’s still large amount, as far as phenotypical traits are concerned), but grows to 80%+ in adulthood, even higher than that if you correct for attenuation (i.e. measurement error, which will always push the heritability down), and consider g factor instead of IQ scores (which is how intelligence is usually operationalized). IQ has been found to be exceedingly good vehicle to study the notion of intelligence, as the (most replicated finding in psychology) existence of positive manifold (google it) and g factor means that all non-contrived ways of measuring what humans usually understand intelligence is, yield pretty much the same thing, especially once you perform factor analysis. Here is an overview paper by one of the leading researchers in the field (and one of the most distinguished researchers in psychology at large) Robert Plomin: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4270739/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4270739/ Unlike the rest of psychology, psychometry as a field does not have any kind of replication problem: all major results have been replicated many, many times on many different data sets. You can go to Google Scholar and find probably hundreds of replications (keyword is “heritability of intelligence”). Here is for example one from Japan: https://link.springer.com/article/10.1007/BF01067719 https://link.springer.com/article/10.1007/BF01067719 which finds heritability to be 50% among 12 year olds, here is one from Norway https://emilkirkegaard.dk/en/wp-content/uploads/On-the-question-of-secular-trends-in-the-heritability-of-intelligence-scores-A-study-of-Norwegian-twins.pdf https://emilkirkegaard.dk/en/wp-content/uploads/On-the-quest... finding 70% among military recruits, you can go on and on. > I also think we can only accept that we're born different, but human. If we should aspire to anything, it should be to make life good for every individual, taking their capacities into account, not to give everyone an academic degree. Clearly, but if the society denies reality, the result is expansion of higher education among people who can’t benefit from it, bullshit degrees, student debt, and general misery.
- qqqwerty 5y ago
  Robert Plomin is not without controversy: https://blogs.scientificamerican.com/beautiful-minds/there-is-no-nature-nurture-war/ https://blogs.scientificamerican.com/beautiful-minds/there-i...

by tgv 5y ago

NoImmatureAdHom 5y ago

Here's a relatively recent study: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4270739/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4270739/ I agree with your sentiment in the second paragraph. Human gets a little fuzzy, though...I think you really mean to point at personhood. There are humans who definitely aren't people, like those born without brains. And with the computers our grandkids will install--oh my! I'll cross that bridge when I get to it.

mewpmewp2 5y ago

The percentage without context does not give any actual information. E.g. one could argue that environment affects 99 percent of intelligence as for example if someone dies due to environment there's no intelligence at all. So there must be some poor environment A and good environment B, and some poor genes A and good genes B that a comparison must be made between to understand exactly what this percentage means and of course there must be a definition of intelligence and a way to measure it.

NoImmatureAdHom 5y ago
Thanks for asking, I should've explained. The percentage here is percent of variance (https://en.wikipedia.org/wiki/Variance https://en.wikipedia.org/wiki/Variance). What it means, basically, is the extent to which you can predict a child's intelligence just knowing the parents' intelligence--not assuming the child was raised by those parents. In your second paragraph, you've actually hit on one of the apologetic clichés that's popular now. People will say, "Yes, 70-80% of variance...GIVEN OUR CURRENT ENVIRONMENT". And they will act as if they've said something profound. Yes, that's true, and we don't know about the heritability of intelligence in environments that don't exist...but we can make really good guesses. Further, from a public policy perspective, we've got to work in the environment that we've got. And in that environment, the number is 70-80%.
- Ma8ee 5y ago
  No, from a public policy perspective, the important question is what environment can we create that benefit as many people as possible. The current environment, from prenatal care to availability, cost and quality of higher education is something that is created by public policy. It is certainly not anything given.
  - xyzzyz 5y ago
    > No, from a public policy perspective, the important question is what environment can we create that benefit as many people as possible. The problem is that since there already is substantial variance in environment that different people experience today, but nevertheless the amount of variance explained by shared environment is very, very low, this means that if we want to increase intelligence using environmental interventions, you can’t designate some environment that some (eg. well off people) already experience, and get everyone into that environment, because it simply won’t work. If it did, it would already show in the amount of variance explained by environment. Instead, what you need to do is to intervene by putting people in environments very few if any people today experience. This is the only approach that can work, as it can overcome the low amount of variance explained by environment. Suffice to say, nobody yet figured out what those unusual environments actually would be like, as you can’t simply copy whatever well off or genius people grow up like. If you do come up with something, it might end up being a hard sale too, given that this will be necessarily stranger than what people normally expect. But, if it works, you’ll improve the world massively and make history. Chances are against you though, as millions of people in the education industry worldwide have already tried almost anything you could come up with, and nothing really works.
  - tgv 5y ago
    > what environment can we create that benefit as many people as possible That can't be researched (effectively). Policies affect the current situation, not the desired one.
    - Ma8ee 5y ago
      You create the desired situation by affecting the current situation.

xyzzyz 5y ago

70% is actually on the low side of today’s results. Observed heritability is lower in early childhood (meaning the amount of variance in intelligence among children explained by genes is “only” 20%-50%, “only” in quotes because it’s still large amount, as far as phenotypical traits are concerned), but grows to 80%+ in adulthood, even higher than that if you correct for attenuation (i.e. measurement error, which will always push the heritability down), and consider g factor instead of IQ scores (which is how intelligence is usually operationalized). IQ has been found to be exceedingly good vehicle to study the notion of intelligence, as the (most replicated finding in psychology) existence of positive manifold (google it) and g factor means that all non-contrived ways of measuring what humans usually understand intelligence is, yield pretty much the same thing, especially once you perform factor analysis. Here is an overview paper by one of the leading researchers in the field (and one of the most distinguished researchers in psychology at large) Robert Plomin: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4270739/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4270739/ Unlike the rest of psychology, psychometry as a field does not have any kind of replication problem: all major results have been replicated many, many times on many different data sets. You can go to Google Scholar and find probably hundreds of replications (keyword is “heritability of intelligence”). Here is for example one from Japan: https://link.springer.com/article/10.1007/BF01067719 https://link.springer.com/article/10.1007/BF01067719 which finds heritability to be 50% among 12 year olds, here is one from Norway https://emilkirkegaard.dk/en/wp-content/uploads/On-the-question-of-secular-trends-in-the-heritability-of-intelligence-scores-A-study-of-Norwegian-twins.pdf https://emilkirkegaard.dk/en/wp-content/uploads/On-the-quest... finding 70% among military recruits, you can go on and on. > I also think we can only accept that we're born different, but human. If we should aspire to anything, it should be to make life good for every individual, taking their capacities into account, not to give everyone an academic degree. Clearly, but if the society denies reality, the result is expansion of higher education among people who can’t benefit from it, bullshit degrees, student debt, and general misery.

qqqwerty 5y ago
Robert Plomin is not without controversy: https://blogs.scientificamerican.com/beautiful-minds/there-is-no-nature-nurture-war/ https://blogs.scientificamerican.com/beautiful-minds/there-i...