Dak
mentat
No one's saying there aren't measurable differences, and the author of that piece says as much.
By title alone, finding differences is sold as unethical. It specifically raised South Africa as an example of why such investigation is bad and confounded, and attacks Jewish scientists as being bigots. That's anti-Semitic! Clearly an unethical bias.
The bigger problem with the piece is the author is lying at worst or obfuscating/showing ignorance at best:
The problem was that most of his identical twins were adopted into the same kinds of middle-class families. So it was hardly surprising that they ended up with similar IQs. In the relatively few cases where twins were adopted into families of different social classes and education levels, there ended up being huge disparities in IQ – in one case a 20-point gap; in another, 29 points, or the difference between “dullness” and “superior intelligence” in the parlance of some IQ classifications. In other words, where the environments differed substantially, nurture seems to have been a far more powerful influence than nature on IQ.
A 30 point difference isn't enough to make this difference.
https://en.wikipedia.org/wiki/IQ_classification
The Wechsler Adult Intelligence Scale (WAIS) is pretty much the standard IQ test at this point, and has been for some years now. The scale runs as follows:
130 and above Very Superior
120–129 Superior
110–119 High Average
90–109 Average
80–89 Low Average
70–79 Borderline
69 and below Extremely Low
The biggest boost from "dullness" (whatever that is), which would be at best "Borderline", at 30pts would be "Average" (Even low average would only get to high average). I don't know if Bouchard was using an older version of the WAIS, but neither does the writer apparently, since there were no links (or he doesn't want to show them). Given that changes are supposed to be shown over time, I would assume relatively recent IQ comparisons would be using the WAIS-III or WAIS-IV.
He also lies about IQ tests testing a "sliver":
Yet people have not changed genetically since then. Instead, Flynn noted, they have become more exposed to abstract logic, which is the sliver of intelligence that IQ tests measure. Some populations are more exposed to abstraction than others, which is why their average IQ scores differ. Flynn found that the different averages between populations were therefore entirely environmental.
This finding has been reinforced by the changes in average IQ scores observed in some populations. The most rapid has been among Kenyan children – a rise of 26.3 points in the 14 years between 1984 and 1998, according to one study. The reason has nothing to do with genes. Instead, researchers found that, in the course of half a generation, nutrition, health and parental literacy had improved.
The only subtest on the WAIS to test verbal abstraction is the "Similarities" test.
https://en.wikipedia.org/wiki/Wechsler_Adult_Intelligence_Scale
Information & Vocabulary are based on English/Western history canon (although not specifically history about western hist), but not abstract. The rest test either symbolic reasoning or numeric based memory. Separately, the Wechsler Memory Scale tests numeric, symobolic, and linguistic memory if one has trouble with numeric memory only.