Jewish culture has a very strong and extremely ancient tradition of networking and giving to the community, one that Afro-Americans lack. With Asian-Americans it's largely similar, plus consider that the Asian immigrants to the US must have already been the most driven and novelty-seeking of their class back home.

U.S. Blacks carry a unique history of slavery and such. They did not know how to choose between cooperation and defection, because sticking together had never been a choice before.