My school is like Alex's- its racial makeup is maybe 92% white, 6% Native American, 1% Asian, and 1% black- extremely undiverse racially. Because there are so few minorities, there really isn't much segregation (any person who only made friends with other minorities would be very lonely indeed), but there is a kind of clumping. For example, an Asian person would probably know the most of the other Asian kids in school and would be friends with some of them, but most of their friends wouldn't be Asian. There's pretty bad discrimination against Native Americans, but not so much against other races, if my view from the outside is accurate.

I think race is an example of human beings' propensity to pick out patterns and make generalizations. People from the same area historically TEND to share some physical characteristics and people from the same area also TEND to share customs- this is the entire basis of our idea of race. It leads to stereotyping and ignores individuality because generalizations are never completely true, but it's hard to get past it because some generalizations can have some element of or basis in truth.