Posted by:
Concrete Zipper
(
)
Date: May 30, 2017 01:53PM
C Wrote:
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> What do we know? Studies of identical twins raised
> apart reveal that intelligence has a mostly
> genetic basis.
There does appear to be a large genetic component to intelligence, yes. You need the right mix of genes to have a higher IQ but, as Tevai pointed out, even with those genes, environmental factors can screw it all up. Intrauterine conditions can be extremely influential on how children turn out.
> Environmental interventions to
> raise IQ (such as raising a black child in a white
> family) have had very limited success.
There are no good, controlled studies of this, probably because such would be next to impossible to accomplish.
> Billions of
> dollars have been spent on the program Head Start
> to help socioeconomically disadvantaged children
> in school but we haven't seen much in the way of
> results.
Head Start programs have not shown lasting increases in IQ scores of the participants, but they were never designed for that. Whether the programs provide other benefits that outweigh their expense is a matter of debate that is unrelated to this conversation. The methods used by Head Start cover only a small portion of the possibly ways in which socioeconomic status could have an effect on IQ, so Head Start's inability to change IQ cannot be used to rule out the possibility that statistical variations in IQ scores have a socioeconomic (or other, non-genetic) basis.
> Charles Murray wrote about average
> differences in intelligence between races in his
> book The Bell Curve. I think we'll see more
> confirmation of his views in the coming years as
> we come to know more about the human genome.
> Evolution did not stop 60,000 years ago when
> certain groups left Africa.
I read The Bell Curve when it came out in 1994, along with Stephen Jay Gould's "The Mismeasure of Man" and Lewontin, Rose and Kamin's "Not in Our Genes". All three are problematic treatments and probably reflect more of the authors' prejudices than they should. Yes, genetics is a strong factor in IQ. No, it is not easy to measure IQ across cultural, language and socioeconomic barriers, even with straightforward tests like Raven's Progressive Matrices.
If you believe that statistical variations in IQ between racial groups are proof of genetic differences, then would you explain the Flynn Effect similarly? You can read about the Flynn effect in Wikipedia.
https://en.wikipedia.org/wiki/Flynn_effectIn a nutshell, the effect is that average IQs have been increasing by about 3 points per decade, worldwide. Are we evolving that fast? No. Other, non-genetic factors are at play, and may have to do with maternal and early childhood nutrition, among other things. The Flynn effect has shown as large a discrepancy between populations over time as other tests have shown between concurrent racial groups. So the Flynn effect can't be genetic but the racial effect has to be? That's a problematic position to take.
And let's look at the possible roots of genetic differences between those with African ancestry and those with other ancestry. Sub-Saharan Africa is where humans evolved and there is more human genetic diversity there alone than on the rest of the planet. Some 50 to 100 thousand years ago, various groups of anatomically modern humans left African and populated Europe, Asia and Melanesia. When did the supposed genetic division of intelligence happen? Did only the smart ones leave and only the dumb ones stay? Did the division happen after they left Africa? If so, why are all the non-African humans statistically smarter? Shouldn't only some of them be smarter and the rest the same as the massive and diverse population left in Africa? Do you think some evolutionary pressure forced the geographically dispersed non-African populations to be smarter while a contrary evolutionary pressure forced the genetically diverse African populations to be dumber? It's difficult to come up with an evolutionary scenario that fits the hypothesis that African genetics provides lower average IQs.
Look, we don't mind discussing difficult topics, but please argue scientific facts instead of repeating inflammatory rhetoric copied from cherry-picked web sites.
CZ