Time to get hammered for sounding like a racist....
Race has nothing to do with anything.
Culture has everything to do with everything.
You cannot blame oppression for the lack of family structure, education and acheivement.
Want proof? Look at the Jews...had it JUST as bad (perhaps worse?) than anyone and for a MUCH longer period of time (lets say at least 1500 years of oppression).
So why have the Jews (just one example, think of others if you like) been able to thrive, maintain a healthy family structure, sense of education and civilization?
Their culture. Even in the ghettos of Eastern Europe, midst pogroms, or during the Crusades midst slaughter, rape, kidnapping etc, even after (and DURING) the Holocaust (throw in countless other intensely difficult times of oppression) they had an advanced culture unique unto themselves. They had an educational and pedagogical system which they (created?) used since before the Roman conquest. They had their own language, religion, ideology, etc.
Unfortunately, most native peoples (those from Africa, the New World etc) had none of this. Many had not invented an alphabet! Most lived in small tribal communities which were at constant war with other tribal communities.
So when you take a group of people away from a tribal community, that has no writing system, no clear distinct self identity, none of the strong marks of culture, beat them down and oppress them, they have nothing to cling to in order to combat said oppression.
I think much of the "ethnic disparity" you see in South Africa and the United States is due to this. Unfortunately, these tribal cultures had simply not been advanced enough, culturally, to be able to withstand the horrors that they went through.
"Knowledge alone is transitory, the outcrop subsequent to 'I desire all things'". - A. O. Spare