That's just your instinct telling you not to waste your genetic materials on a completely worthless and incompatible mate, or else you'll produce something less than the sum of it's parts. Seriously - I've seen and interacted with niglets spawned from mudsharks. The intelligence and the potential for it is simply lost. Africans carry many different genes that negatively impact intelligence in serious ways. The poor children spawned from these disgusting women have no chance. I honestly feel terrible writing this but it's the truth.