Bingo. There is none -- hence why disparity exists.
My parents cared very much about me taking advantage of every opportunity and "caring" about education. I'm sure many of the poeple who are on here had parents who did the same, or else you probably wouldn't be here.
And I'll do the same for my kids. The cycle will continue on.
I do not agree that this adequately explains disparity. It is a factor, of course. Since this discusison is about affirmative action we'll focus on disparity between blacks and whites.
From what you said, I ask two questions:
If we assume that black parents do indeed push their children less, why is this the case? Is it because black parents are somehow inherently less driven to push their children? Asserting that is borderline racist, and difficult to substantiate at best; I hope you'll agree with me that that is not the reason for the lessened emphasis on academics. So from where does it arise? I would argue that it arises out of a long history of not seeing the education system work for them, a relatively recent access (a few generations, maybe two for it to be widespread) to higher education and more limited opportunity after that education is completed - that is to say, directly out of the history of systematized racism in America.
Second, if two children, one black, one white, have the same emphasis on academics at home, would they end up the same? My money is that, on average, you would see less acheivement, however defined, from the black children, on average. This points to a systemic mechanism of producing disparity.
What I'm trying to say is, blaming the parents for not pushing the kids is an oversimplification.
EDIT: As for the personal accountability aspect, I think my response is easily translatable into those terms.