This is a great summary you've written here and worth a second read. In deed there are confounding cultural factors built into standardized IQ testing. You wouldn't expect a white European student, even from another English-speaking country like the UK, to arrive at one of our school and test as highly as children born in the US. There will always be some exceptional cases, but in general environmental and cultural factors make IQ testing highly culture-specific.
What we need to ask ourselves here in the US is why some children get left behind culturally, or why some children live in disadvantaged environments, broken homes or single-parent households. Solving those problems would quickly close the IQ gap by giving more equal opportunity to all children.
As I said, the confounding factors exist, but they seem relatively minor. Attempting to effectively homogenize the diverse human gene pool through education is anything but a new effort. If it was possible to educate the Mbuti pygmies of the Congo into the cognitive equivalent of Great Neck Jews, don't you think someone would have tried this already?
Imagine that the remedy proposed was not educational, but rather pharmaceutical. Someone's selling you a drug that purports to turn Pygmy populations (mean IQ 55 or so - but let's be generous and add 10 points for cultural bias) into Ashkenazi populations (mean IQ 115 or so).
You might ask: has this drug ever been tried before? Is there any evidence that it can work? And what happens if the Beastie Boys take it - do they become the world's leading physicists? These would all be very rational questions.
"If it was possible to educate the Mbuti pygmies of the Congo into the cognitive equivalent of Great Neck Jews, don't you think someone would have tried this already"
Who would try that? The benign, wise rulers of the Congo?
In the Belgian Congo last week massed tom-tom drummers practiced a welcome tattoo. Prosperous Negro shopkeepers climbed up wooden ladders and draped the Congolese flag (a golden star on a blue field) from lampposts and triumphal arches set up along Boulevard Albert I, the spanking concrete highway that bisects the capital city of Leopoldville. In far-off mission churches, encircled by the rain forest that stretches through Belgian territory from the Atlantic to the Mountains of the Moon, choirs of Bantu children rehearsed the Te Deum. African regiments drilled, jazz bands blared in...
If you have a Time subscription (yeah right), you can read the whole thing on line. Otherwise, suffice it to say that (a) the memory hole is a lot deeper than you think, and (b) it's physically possible to teach Bantu children (and perhaps even pygmies) the Te Deum. Not clear that it's a safe and effective method for turning them into the King Ad-Rock, however.
The most interesting, and certainly the most effective, attempt to convert a Stone Age population directly to a civilized lifestyle wasn't even in the 20th century. Or the 19th. Consider the Reductions of Paraguay:
That subsample size is too small - it's just noise.
Although I suppose the Asian adoptees available, as probably with all races, weren't exactly the pick of their gene pool. Blood runs true, you know - on average.
(Ironically, the perspectives on human heredity generally held in the premodern era are generally more accurate than those taught in modern schools today. The traditional ideas of "blood" were after all consistent with a broad cultural understanding of animal husbandry, and the mechanisms of heredity aren't any different in humans than in pigs.)
What we need to ask ourselves here in the US is why some children get left behind culturally, or why some children live in disadvantaged environments, broken homes or single-parent households. Solving those problems would quickly close the IQ gap by giving more equal opportunity to all children.