Who's Right; Cosby or Sharpton?

A new poll of Black Americans reveals some interesting information. It states that, for the first time, more Blacks believe that Black people's lack of economic progress stems from lack of personal responsibility and not racial discrimination. It goes on to say that 61% of respondants believe that more differences stem from class then from race,and 57% of Blacks with less then a high school education believe that middle-class Blacks are more like middle-class whites than poor Blacks. That said, most Blacks still thought that discrimnation plays a part in hiring and housing decisions (the vast majority of whites did not), and fewer Black Americans see life getting better in the future.
The one that got me though was the statistic that 45% of Black children in middle-class families slip into lower economic brackets in adulthood, while only 16% of white middle-class children do the same. Are there that many more Black kids that won't take enough personal responsibility to stay afloat in the middle-class waters? Or are there more systemic, structural forces at work that keeps Black Americans from keeping the wealth that they may attain?

What'd'ya think???