Those who study sociology will be familiar with Tony Sewell's thesis on the educationally underachievement of black students - in particular black boys from Caribbean backgrounds. In a nutshell, the working class culture in which they are embedded narrows their horizons and limits their aspirations. It's all about class, not race. While I think Sewell may underplay the structural aspects of working class culture and economic relations which limit the possibility of opportunities, he is (obviously) onto something.

Here's an article written following David Cameron's criticism of Oxford University for the low level of black undergraduate recruitment.