I've read about widespread inbreeding among Muslims, and can agree that the practice is very probably causing a decline in average intelligence amongst them, but that cause/effect pattern doesn't exist in any significant presence among American blacks.
Again, the burden of proof isn't on me, because I'm not the one making the claim that blacks have lower average intelligence than other racial groups. I don't see any evidence of your assertion, though I readily admit that a large percentage of blacks have educational and cultural deficits.
What interests me is what it is the gives that spark that drives the climb and sustaining, and indeed, the continuing rise, of civilization.
All around the world there is evidence of great innovations, great ideas, and engineering feats, whether ancient or modern, but very little in Africa.
Cultural and education “deficits” (especially in America) exist for what reason?
IMO, they are merely an excuse.
Not saying if I was living in a tropical paradise that my interest in “improving” things would be that great. But presented with information on how to improve things, I’m pretty sure I would use that information, with capacity.