Great thread.
I grew up and went to school in a predominantly white suburb where the median household income was ~$90k. The situation I saw w/ the blacks there was pretty unique, I think it would have been an incredible sociological study. From what I observed there, I think hip-hop plays a big part in the black middle class underachieving-- but it's only able to do so because of deficiencies in parenting and/or knowledge of black history.
I've never been able to come across any press on it, but the story was that a large percent of the black population in this suburb came in after the city of Atlanta tore down some projects to make way for the Olympics in 1996. Supposedly, the city of Atlanta wanted to do right for the people that were being displaced, so some arrangement was made so that these people would get some sort of subsidized housing and relocation to this affluent suburb w/ great schools.
As a consequence, there was a dynamic at the high school I went to where you had black kids whose parents were doctors and lawyers rubbing shoulders with black kids from single parent families w/ hoodish backgrounds. In addition, the black kids composed ~10% of the population of this HS that was ~70 if not 80% white...in a county that went for McCain by ~70% in '08.
I had black friends and classmates who ended up underachieving because they gave in to attacks on their identity both white people and other black people (I remember one of the black dudes from a less well-off background yelling "Black people steal! That's what we do!" in a locker room after getting caught stealing something from someone's locker). Luckily enough, I started reading about sociology & black history early enough to just get pissed off when some white kids suggested I was acting white by not acting out stereotypes. It was also infuriating to hear this from white proto-conservatives for a number of reasons.