[pron]

Probably, but I'd like to point out that this subject has been studied for the past forty years or so, so we can do better than conjecture. While it is true that minorities often feel left out in homogenous groups, there is a big difference between cases where that minority is simply a numeric difference and those where that minority has less power[1] in society. We now know that the discussion of sexism and racism is not about numbers and differences but about certain groups having more power than others, and that causes some very specific behaviors.

[1]: http://en.wikipedia.org/wiki/Power_(social_and_political)