In much of Africa, it can be argued that from the burden of intestinal parasites and malaria, the nutrients literally consumed by pathogens hurt brain development across the board - causing 10-20 point reductions in AVERAGE IQ.
In much of the Middle East, where over half the population marries a paternal cousin, inbreeding depression lowers overall IQ, plus malnutrition for girls because the food is preferentially given to boys.
In the parts of Asia where malnutrition is bad enough to have several million kids go blind from lack of vitamin A, insufficient micronutrients and protein also crimps brain development.
It is estimated that if everyone got a good multivitamin, sufficient iodine, anti-malaria drugs and deworming every month, the average IQ in much of Africa and Asia would go up 10-15 points.
Whether this is enough to raise the African IQ to the Western average isn’t certain, but it would certainly close the gap.
But no amount of schooling will turn a kid left brain damaged by five bouts of malaria into a genius.
Wow! Now I almost feel guilty for Scam Baiting those Nigerian princes. No wonder it was so easy!