Brain size correlates with IQ.
Jayman writes: There are global differences in brain size. Brain size is certainly related to intelligence, both on the individual level (Pietschnig et al 2015) and (even more so) on the group level (though the both the group level and individual level correlations are less than 1.0). In order for Chisala’s idea to work, these environmental insults must also cause certain racial group differences in brain size.
But, as we know, it’s not outside the realm of possibility that environmental insults can affect brain size (see the Zika virus). And sure, sub-Saharan Africa is loaded with pathogens and other environmental insults. But racial differences in brain size are seen between people of European, African, and Asian ancestry in the United States (from Rushton & Jensen, 2010):
…brain structure differs detectably by race….
As we’ve seen before, and as Bryan Caplan recounts, the differences between human groups in development goes back thousands of years – such that level of development as far back as 1000 B.C. is predictive of development today…
It’s not like the poor performers and the strong performers of today are a new thing. They’ve been poor performers and strong performers throughout history (by and large). Indeed, in sub-Saharan Africa:
Why this meandering reminiscence of mine about a random ruin in Turkey? Because sub-Saharan Africa has remarkably few ruins for its immense size.
This fact is not well known. It is so hazy in the contemporary mind that Henry Louis Gates managed to sell PBS on a six episode miniseries about African ruins called The Wonders of Africa without, apparently, anybody in PBS management calling his bluff about the lack of wonders that his camera crew would wind up documenting in one of the most boring documentary series of the 21st Century.
