Chanda Chisala wrote an article in the Unz Review claiming to have falsified racial hereditarianism. Chisala bases his claim on the lack of “regression to the mean” seen in African immigrants to the UK. This lack of regression to the mean is not a falsification of the hereditarian position.
How much regression to the mean should you expect?
Chisala cites the Journal of Blacks in Higher Education which provided the following chart of 2008 SAT scores by race and income:
Chisala uses this chart to argue there is substantial regression to the mean in African Americans, consistent with the hereditarian hypothesis. This regression to the mean is missing in African immigrants, “disproving” the hereditarian hypothesis. He writes:
To make this totally clear, we can perform a short thought experiment. Let’s say we took a number of black American elites to the UK as expatriate workers, selected only from those professionals who make 200,000 dollars a year in their homes. Would their children perform significantly above the white average in the UK on academic tests? No. It is the same children who perform below the poor white children in America; a plane ride would not suddenly make them smart. This means that there will also be a gap between black American children and black African children (especially the English-speaking ones) in the UK that is similar to (or even larger than) the persistent gap between blacks and whites in America, thus confirming that their regression in America has nothing to do with racial IQ genetic potentials (it’s not a black and white issue).
But do the children of Black professionals really score lower than American poor Whites? No they don’t. To see why, I’ll convert those SAT scores onto an IQ like scale with a mean of 100 instead of 1017, which is what it was in 2008, and a standard deviation of 15 instead of 231, which is what it was in 2012(I couldn’t find the SD data for 2008):
Now you see what’s wrong with that graph. It’s not a representative sample. Not everyone takes the SAT and the higher income kids are more likely to take it than the lower-income kids. How many of the kids whose parents make more than 200k take the SAT? Probably almost all of them, no matter how dull they are their parents will make them take the test. Of the kids whose parents make under 20k only those who expect to go to college take the test. So this data does not prove that the children of Black American professionals are not as smart as the children of the White lower class. In fact it shows that they have a score that is probably similar to that of the average White, note that the score of 97.7 is compared to other students who take the SAT, a population that is smarter than average. So if we “took a number of black American elites to the UK as expatriate workers, selected only from those professionals who make 200,000 dollars a year in their homes” we should expect their children to score similar to White Britons, just as the children of the African cognitive elite do.
In the Bell Curve a similar pattern is reported for the relationship between race, IQ and socio-economic status. From The Bell Curve page 288:
Note that at the 10th decile the Black children have slightly above average IQs.