Not that I feel I need to do km any favors, but I remember clearly from one of those oh so useful sociology classes I took:

"A minority is a sociological group that does not constitute a politically dominant voting majority of the total population of a given society. A sociological minority is not necessarily a numerical minority it may include any group that is subnormal with respect to a dominant group in terms of social status, education, employment, wealth and political power. To avoid confusion, some writers prefer the terms "subordinate group" and "dominant group" rather than "minority" and "majority", respectively."

It came from wiki b/c that's always the easiest source, but I am sure there are others.
We are what we repeatedly do - Aristotle