I'm lily-white, from a largely lily-white (mostly German, Irish and a little Italian) small town in IL (around 10,000 population). There's a very light sprinkling of nonwhites, but not enough to teach us to recognize one group from another. Without external media coming in and various generations of military veterans, we'd probably do little better than to be able to distinguish blacks from Hispanics from Asians.
I've covered a lot of ground since then and I'm doing better at telling different groups apart. But it looks like I'm not the only one who has a heck of a time distinguishing Chinese, Koreans and Japanese.
Let's see how well you do. Har har - I did better than Razib...
Stolen from Gene Expression.