Why to then immigrants coming here in poverty worse than blacks do well within a generation while blacks can't despite preferential treatment and quotas?
Because the Africans came from a tribal society.
Not only did the Europeans come from countries with much more developed technology.
But these societies were also much more developed, generally.
Africans didn't have a civil tradition, didn't have social organisations, networks, et al.
It was all tribal.
Putnam's study in Italy showed how important developed social networks in a society are.
South Italy is much less democratic than north Italy. Lower participation in elections et al.
The difference, concluded Putnam, was that in the north there had been a lot of networks for several hundred years, eg church choirs, sport clubs and what not. In the south - not so much.
I would bet anything that African-Americans are less involved in social networks than other ethnicities in general.
