Umm, should we believe that the perhaps the most important attribute of homoSap is not under genetic selection? Everyone that has raised kids and seen their grandkids develop knows that intelligence is not equally granted to all. Everything that could be selected for (because there is a phenotypical difference) is by definition selected.
If you really want to get precise about it, what is being selected for is the capacity to have a given IQ in good environmental conditions. Obviously, there are environmental circumstances (e.g. lead exposure) that can prevent people from reaching their potential.
I am on the left. This doesn't mean that IQ isn't real. It may mean that at a large population level that environmental deprivation can impair people reaching their full potential intellectually. Indeed, there is solid evidence that, e.g., children who test as "gifted" at a young age underperform their potential when they grow up in very bad schools.
What are the odds that some historical alleles for intelligence are not well-represented in modern populations, and thus the estimates for Mesolithic foragers are low? There may also be newer mutations not present in them. I find it hard to believe that with their greater cranial capacities, all that additional material was or naught. Unless perhaps the modern, moderately high correlation between MRI-measured brain volume and intelligence is an artifact of current evolutionary trends.
Good schools are all the same, but each bad school is terrible in its own way. One of the girls, that spent so much time in our house that she refers to us as her parents, got a teaching degree and taught in a downtown Houston high school for five years. She wanted to make a difference for the children who didn't have access to the good schools. This small, petite blond was physically assaulted every year. The school administration/board did nothing as this was accepted as "that's just the way it is". So now she teaches in a rural/outer-suburban school where such behavior doesn't happen. What can a gifted child in a bad school do? Hope your parent move to a good school district I guess. (This is 20 years after the Texas school systems were reorganized to provide equivalent funding for all schools.)
Otanes. This is a fair point. I've thought about it. And, it probably accounts for some of the effect. But probably not much of it. Most phenotype change due to genotype change arises from different frequencies of gene variants within existing variation. "Hard selective sweeps" completely remove a gene variant from a population, but those pretty much happen only when another variant provides a decisive selective fitness advantage when a population size is stable or expanding, which covers most of human history over the last 10,000 years (there were some bottlenecks earlier but those populations aren't present in this sample, and the selective sweeps in the last 10,000 years which are known pretty well, didn't act on IQ index genes, and especially not IQ index genes that favor higher IQ). This possibility would be much more likely if one was looking at say 100,000 year old ancient DNA or Neanderthal DNA where lots of it was lost to random chance from small population sizes and or extinction with only partial genetic introgression.
@Otanes "I find it hard to believe that with their greater cranial capacities, all that additional material was or naught." Mesolithic hunter-gatherers were surely smarter than their archaic hominin ancestors. In the case of Neanderthals, they had bigger brains relative to body size and may have been smarter than early modern humans in one sense, but they seem to have been much less "plastic" (i.e. capable of learning new things culturally and adapting), while Neanderthals were probably more "hard wired." This is evidenced, for example, by the much greater rate of technological change in modern humans than in Neanderthals (until the very end where Neanderthal technological innovation may have been related to modern human admixture and copying modern humans that they encountered).
13 comments:
you believe in iq from dna
Umm, should we believe that the perhaps the most important attribute of homoSap is not under genetic selection? Everyone that has raised kids and seen their grandkids develop knows that intelligence is not equally granted to all. Everything that could be selected for (because there is a phenotypical difference) is by definition selected.
"you believe in iq from dna" yes.
If you really want to get precise about it, what is being selected for is the capacity to have a given IQ in good environmental conditions. Obviously, there are environmental circumstances (e.g. lead exposure) that can prevent people from reaching their potential.
i thought you are on the left. the left knows iq disfavors certain races and is a tool for oppression
I am on the left. This doesn't mean that IQ isn't real. It may mean that at a large population level that environmental deprivation can impair people reaching their full potential intellectually. Indeed, there is solid evidence that, e.g., children who test as "gifted" at a young age underperform their potential when they grow up in very bad schools.
What are the odds that some historical alleles for intelligence are not well-represented in modern populations, and thus the estimates for Mesolithic foragers are low? There may also be newer mutations not present in them. I find it hard to believe that with their greater cranial capacities, all that additional material was or naught. Unless perhaps the modern, moderately high correlation between MRI-measured brain volume and intelligence is an artifact of current evolutionary trends.
Lead in Rome: https://www.sciencedaily.com/releases/2025/01/250106195701.htm
Good schools are all the same, but each bad school is terrible in its own way. One of the girls, that spent so much time in our house that she refers to us as her parents, got a teaching degree and taught in a downtown Houston high school for five years. She wanted to make a difference for the children who didn't have access to the good schools. This small, petite blond was physically assaulted every year. The school administration/board did nothing as this was accepted as "that's just the way it is". So now she teaches in a rural/outer-suburban school where such behavior doesn't happen. What can a gifted child in a bad school do? Hope your parent move to a good school district I guess. (This is 20 years after the Texas school systems were reorganized to provide equivalent funding for all schools.)
Otanes. This is a fair point. I've thought about it. And, it probably accounts for some of the effect. But probably not much of it. Most phenotype change due to genotype change arises from different frequencies of gene variants within existing variation. "Hard selective sweeps" completely remove a gene variant from a population, but those pretty much happen only when another variant provides a decisive selective fitness advantage when a population size is stable or expanding, which covers most of human history over the last 10,000 years (there were some bottlenecks earlier but those populations aren't present in this sample, and the selective sweeps in the last 10,000 years which are known pretty well, didn't act on IQ index genes, and especially not IQ index genes that favor higher IQ). This possibility would be much more likely if one was looking at say 100,000 year old ancient DNA or Neanderthal DNA where lots of it was lost to random chance from small population sizes and or extinction with only partial genetic introgression.
@Otanes "I find it hard to believe that with their greater cranial capacities, all that additional material was or naught." Mesolithic hunter-gatherers were surely smarter than their archaic hominin ancestors. In the case of Neanderthals, they had bigger brains relative to body size and may have been smarter than early modern humans in one sense, but they seem to have been much less "plastic" (i.e. capable of learning new things culturally and adapting), while Neanderthals were probably more "hard wired." This is evidenced, for example, by the much greater rate of technological change in modern humans than in Neanderthals (until the very end where Neanderthal technological innovation may have been related to modern human admixture and copying modern humans that they encountered).
@Guy Texas is particularly bad, but it is a problem in most states. We could do better.
@DDeden Indeed. Good catch.
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