3 ms·

We do know that genes are a cause of IQ (we can see this comparing our nearest non-Homo relatives. But yes, we are far away from saying which genes do cause it,

We do know that genes are a cause of IQ (we can see this comparing our nearest non-Homo relatives. But yes, we are far away from saying which genes do cause it, much less how they cause it, and how they interact with the environment and other genes to cause it.

mjburgess 3y ago
IQ is a test, it isnt intelligence and isnt even a measure of intelligence. It is valid only for establishing certain sorts of mental retardation in a human population. To say that "genes cause IQ" is several levels of confusion. The claim has nothing to do with whether genes determine the physiological body structure, the claim is whether relevant aspects of human intelligence are a product of the at-birth or developmental structure -- or of that acquired from the environemnt, ie., neural plasticity / brain structure / etc. Almost all evidence we have is that relevant aspects of human intelligence are environmental, ie., acquired. There is little evidence of the alternative because the experiments needed to establish it are large impossible or unethical. So it might be true, but we have no evidence of it. Insofar as any claims are made about genes and IQ they amount to associating markers of geographical-historical migration (ie., breeding across time) with a very bad proxy measure of abstract reasoning which, at best, only detects deficits with any reliabiliy. So we have proxies on top of correlations on top of terrible measures of anything with zero reliability in the range of interest. This whole thing is operating nearly at fraudulent levels of "research". There's very very little this field can say scientifically, since there arent any experiments. It's all pseudoscientific uses of stats. To simplify matters, suppose that we know for sure that all above-average differences in IQ are 100% environmental/acquired-during-lifetime. Now, so what do twin studies show, on this assumption? They show that genes must be correlating with these environmental measures, and twin studies give us an 'effect size' for geographical-historical patterns of reporduction. So twin studies, even if they were valid (and their assumption of linearity renders them invalid), do not decide the matter. You need indpednent evidence of causal mechanisms from experiments, which doesnt exist.
- sokoloff 3y ago
  > IQ is a test, it isnt intelligence and isnt even a measure of intelligence. Are you sure about that? If I find someone that we all agree is “pretty damn smart” and they regularly score 115+ and we find someone that we all agree is “not very smart at all” and they regularly score < 90. And we repeat that dozens of times, it seems like the IQ test is a measure of intelligence. It may be imperfect, and pretty clearly does not have three significant digits of precision, but it seems it’s still a measure of the thing we’re trying to estimate, same as a set of mixed stones and a playground seesaw can provide a comparative measure of weight.
  - mjburgess 3y ago
    Er, sure, if you can define some objective measures of performance that are taken to be symptomatic of intelligence and correlate those with IQ test results -- and then show test-retest validity across a wide population (etc. etc.), then you'd have a case. But all attempts to do this, i'm aware of, show in fact IQ tests don't behave this way. That all correlation with objective measures of performs, with reliable measures, end up random >100 -- and weakly non-random <100. So what we, in fact find, is that IQ tests only reliably correlate in the 'mental retardation' region of performance. There is, possibly, a sort of non-objective culturally feeling to the kinds of people who might do well on IQ tests. Call these personalities, "puzzler bureaucrats" it isnt clear that even for people in this population we're percing any sort of objective intelligence-related performance. Eg., suppose we had an objective measure of intelligence based on a deep causal model of the brain and how it interacts with body/environment. Suppose we found out that a population who score 100-110 on IQ tests were vastly more intelligent than another scoring 120-130. Now, could we find independent measures of performance to substantiate that? Yes, trivially. Take, eg., a group of CEOs and a group of maths undergrads. The former, could by supposition, have a much higher performance on a variety of objective measures.
    - sokoloff 3y ago
      > So what we, in fact find, is that IQ tests only reliably correlate in the 'mental retardation' region of performance. Even assuming we agree that that’s the only usefulness of an IQ test, in what way does that make them not a measure of intelligence? A ruler is still a measure of length even if it can’t measure the size of an atom or the distance to the moon.
deleted 3y ago
[deleted]

mjburgess 3y ago

IQ is a test, it isnt intelligence and isnt even a measure of intelligence. It is valid only for establishing certain sorts of mental retardation in a human population. To say that "genes cause IQ" is several levels of confusion. The claim has nothing to do with whether genes determine the physiological body structure, the claim is whether relevant aspects of human intelligence are a product of the at-birth or developmental structure -- or of that acquired from the environemnt, ie., neural plasticity / brain structure / etc. Almost all evidence we have is that relevant aspects of human intelligence are environmental, ie., acquired. There is little evidence of the alternative because the experiments needed to establish it are large impossible or unethical. So it might be true, but we have no evidence of it. Insofar as any claims are made about genes and IQ they amount to associating markers of geographical-historical migration (ie., breeding across time) with a very bad proxy measure of abstract reasoning which, at best, only detects deficits with any reliabiliy. So we have proxies on top of correlations on top of terrible measures of anything with zero reliability in the range of interest. This whole thing is operating nearly at fraudulent levels of "research". There's very very little this field can say scientifically, since there arent any experiments. It's all pseudoscientific uses of stats. To simplify matters, suppose that we know for sure that all above-average differences in IQ are 100% environmental/acquired-during-lifetime. Now, so what do twin studies show, on this assumption? They show that genes must be correlating with these environmental measures, and twin studies give us an 'effect size' for geographical-historical patterns of reporduction. So twin studies, even if they were valid (and their assumption of linearity renders them invalid), do not decide the matter. You need indpednent evidence of causal mechanisms from experiments, which doesnt exist.

sokoloff 3y ago
> IQ is a test, it isnt intelligence and isnt even a measure of intelligence. Are you sure about that? If I find someone that we all agree is “pretty damn smart” and they regularly score 115+ and we find someone that we all agree is “not very smart at all” and they regularly score < 90. And we repeat that dozens of times, it seems like the IQ test is a measure of intelligence. It may be imperfect, and pretty clearly does not have three significant digits of precision, but it seems it’s still a measure of the thing we’re trying to estimate, same as a set of mixed stones and a playground seesaw can provide a comparative measure of weight.
- mjburgess 3y ago
  Er, sure, if you can define some objective measures of performance that are taken to be symptomatic of intelligence and correlate those with IQ test results -- and then show test-retest validity across a wide population (etc. etc.), then you'd have a case. But all attempts to do this, i'm aware of, show in fact IQ tests don't behave this way. That all correlation with objective measures of performs, with reliable measures, end up random >100 -- and weakly non-random <100. So what we, in fact find, is that IQ tests only reliably correlate in the 'mental retardation' region of performance. There is, possibly, a sort of non-objective culturally feeling to the kinds of people who might do well on IQ tests. Call these personalities, "puzzler bureaucrats" it isnt clear that even for people in this population we're percing any sort of objective intelligence-related performance. Eg., suppose we had an objective measure of intelligence based on a deep causal model of the brain and how it interacts with body/environment. Suppose we found out that a population who score 100-110 on IQ tests were vastly more intelligent than another scoring 120-130. Now, could we find independent measures of performance to substantiate that? Yes, trivially. Take, eg., a group of CEOs and a group of maths undergrads. The former, could by supposition, have a much higher performance on a variety of objective measures.
  - sokoloff 3y ago
    > So what we, in fact find, is that IQ tests only reliably correlate in the 'mental retardation' region of performance. Even assuming we agree that that’s the only usefulness of an IQ test, in what way does that make them not a measure of intelligence? A ruler is still a measure of length even if it can’t measure the size of an atom or the distance to the moon.

deleted 3y ago

[deleted]