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Would you then also argue that two smart parents have a much higher chance of having a smart kid than two of average intelligence? If not, why not?

benj111 7y ago
I think you might be misinterpreting the parent. When they refer to education reducing potential, they mean higher education levels generally correspond with a lower birth rate, for a variety of reasons. So smart parents having smart children does seem to fit with that. Or am I misunderstanding what you're getting at?
- j_wtf_all_taken 7y ago
  I did mean the "genetic heritability" part of intelligence, if all other factors stay the same (i.e. assuming a scenario as described in the paper, where no environmental factors change) and everyone gets the same level of support in education etc. Hope that helps to clarify.
  - j_wtf_all_taken 7y ago
    Since the discussion in the thread here seems to have stopped, I'll skip to the conclusion: Both fertility and intelligence are not as simple as the color of someones eyes. Lots of genes play a role, so the combination of two favorable gene-sets does not necessarily lead to a still favorable gene-set. Therefore, there always seems to be a "regression toward the mean", so don't worry, one or two generations cancel out all "preexisting conditions". Therefore, in every practical sense, both the heritability of intelligence as well as the heritability of fertility are negligible compared to other factors. Of course children of more intelligent parents tend to get a better education, for example, i.e. those children can develop more of their potential, but here we're back to environmental parameters. But hey, this is good news, because it also works the other way around - dumb parents can have smart kids! So even if dumb people breed like rabbits, we just gotta make sure schools are properly funded to educate those children properly so they can develop their potential!
    - DissidentSci 7y ago
      Intelligence and fertility are known as complex traits. The fact they are complex doesn't mean they are not acted on by genetics: they are just highly polygenic. Almost all attempts to measure the heritability of intelligence have reached estimates between 50 and 80%.
      - j_wtf_all_taken 7y ago
        Did you really read my post? Anyway, I often hear that claim of 50-80% but I can never find the publications backing up that claim. Can you list some, please?

benj111 7y ago

I think you might be misinterpreting the parent. When they refer to education reducing potential, they mean higher education levels generally correspond with a lower birth rate, for a variety of reasons. So smart parents having smart children does seem to fit with that. Or am I misunderstanding what you're getting at?

j_wtf_all_taken 7y ago
I did mean the "genetic heritability" part of intelligence, if all other factors stay the same (i.e. assuming a scenario as described in the paper, where no environmental factors change) and everyone gets the same level of support in education etc. Hope that helps to clarify.
- j_wtf_all_taken 7y ago
  Since the discussion in the thread here seems to have stopped, I'll skip to the conclusion: Both fertility and intelligence are not as simple as the color of someones eyes. Lots of genes play a role, so the combination of two favorable gene-sets does not necessarily lead to a still favorable gene-set. Therefore, there always seems to be a "regression toward the mean", so don't worry, one or two generations cancel out all "preexisting conditions". Therefore, in every practical sense, both the heritability of intelligence as well as the heritability of fertility are negligible compared to other factors. Of course children of more intelligent parents tend to get a better education, for example, i.e. those children can develop more of their potential, but here we're back to environmental parameters. But hey, this is good news, because it also works the other way around - dumb parents can have smart kids! So even if dumb people breed like rabbits, we just gotta make sure schools are properly funded to educate those children properly so they can develop their potential!
  - DissidentSci 7y ago
    Intelligence and fertility are known as complex traits. The fact they are complex doesn't mean they are not acted on by genetics: they are just highly polygenic. Almost all attempts to measure the heritability of intelligence have reached estimates between 50 and 80%.
    - j_wtf_all_taken 7y ago
      Did you really read my post? Anyway, I often hear that claim of 50-80% but I can never find the publications backing up that claim. Can you list some, please?