asians are smart and had a more developed civilization than the west at a point, blacks have never been civilized, also the slaves were a more aggressive people rejected by other blacks in africa
another thing from the large populations of say india and china the very smartest even as a small % are a lot of people and tend to immigrate to the west, this is a good thing as they give us an advantage and those other nations lose their best, the unhinged immigration of millions flooding in is the problem