I recently ran across a book called Basic Concepts of Intercultural Communication. It is a bit long, and many of the articles don't interest me, focused as they are on the different business cultures of the US and Japan (I think it was published at a time when the private sector in the US was still very worried about the competitive threat posed by Japan's economy).
There is one article though that caught my attention on Black and White cultural styles in the workplace. I'm sure some of the author's assertions can be questioned, but I thought it was a useful, honest approach to describe some of the differences in cultural style, and how that can either cause friction or constructive tension in the workplace. The main differences the author highlights are that black culture accords a more protagonistic and semi-autonomous creative role to the individual, while white American culture stresses the uniformity of work processes and the interchangeability of each person (read: the discouragement of too much individual protagonism or flair). Another difference is the black comfort with heated discussion as a means to get to the truth, versus the white suppression of emotion in order to avoid conflict and thus maintain a relative unity and harmony.
You'll have to read the article yourself in order to judge its merit, but one thing I reflected on after reading it is how we're all on a continuum. Some of the traits ascribed to white Americans by this author with respect to black Americans, are precisely the traits ascribed to non-American cultures vis-a-vis general US culture. In other words, where Americans as a whole (when compared to many Europeans or Japanese) are more direct, more independent and individualized, more willing to engage in argument, and less beholden to maintaining harmony and unity, within the US the reference point changes, so black Americans may embody these traits to a greater degree than whites. This is pretty consistent with my very idiosyncratic reading of US culture as basically being what happens when you take a bunch of predominantly European people and inculcate West African values and traditions in them.