Chisala’s Last Word
By James Thompson
[. . .] To summarize the general debate: under what circumstances do real world achievements call into question group tests of intellect? One answer is: when more of the group in question have real-life achievements above what would be expected from their measured average intelligence. In my view there should be no doubt that real world achievements are a better measure of intelligence than predictive assessments.
One straightforward approach is to follow a standard procedure. Take the average intelligence score for the nation; then take the best estimate of the nation’s total population; then calculate how many citizens are above a criterion, say Greenwich Mean Intelligence plus two standard deviations (IQ 130) and then compare that number of bright persons with the number of persons who win intellectual prizes.
[. . .] African Americans should have more high-performing outliers than Africans, per head of population. When corrected for population size the pool of talent to be drawn from is 41 million African Americans and over 1 billion Sub-Saharan Africans (reportedly between 1,014 million and, from the World Population Review, 1023 million). I assume that African Americans at IQ 85 and Africans at IQ 70 and have to compete against each other for IQ 130 occupations, then there will be 167,124 African Americans against 55,345 Africans at that level, so I agree with Chisala that the former should predominate. If Africans do better than African Americans on a broad range of intellectual indicators in the US, this is an important anomaly. We can check this against a common standard school leaving examination in the US.
[. . .] A 130 IQ Sub-Saharan African is a lonely person in terms of having contact with people of that ability. He’s probably more likely to end up running a very efficient smuggling/poaching gang than winning a chess championship. The society around him will be an average 70 IQ society and he will adapt to that environment. Meanwhile, an European of the same 130 IQ ability will be surrounded by people who are as smart as him and the societal structure will reflect that.
Ultimately, it’s the density that counts. The table below http://archive.is/ZV0m8 shows (at 15 SD) that a 100 IQ country will have a 130 IQ (and above) persons everywhere (1:44) while in a 70 IQ country they’ll be very rare (1:31,560).
[. . .] Isn’t it likely that sub-Saharan Africa is simply a lesser version of India? Instead of assuming a uniform population with some mean and SD, it seems to me more likely that sub-Saharan Africa is racially diverse, with certain subgroups like the Igbo ahead of others on the continent in terms of aptitude.
We resolve the paradox of low average IQ scores in India partly by realizing that there are probably high IQ castes from which high achieving Indians are drawn from. Wouldn’t this also imply a regression to a higher sub-group mean for the children of these upper caste Indians? Could not a lesser version of this apply to sub-Saharan Africa? I feel like that would go a long way towards explaining many of the data points Chanda points out…