It is very politically incorrect to say this, but low average cognitive ability seems to be involved. When a population has an IQ average in the 70s or 80s, which many African populations seem to, having well run nation states is difficult. I can’t think of a reason why an entire continent would be developmentally retarded, especially when the genetic evidence tells us that everyone outside of Africa belongs to a common ancestor that left Africa and hybridized with other species of humans (those that remained in Africa did not). The san people in South Africa are actually the oldest population of sapiens genetically speaking.
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