In my 20s I worked with a girl from India. I didn't know anything about India but had read some history of the Caste system. I asked which caste she was from. I expected she'd tell me and I wouldn't even understand what it meant (because I only knew there were castes, not what each one was) and the conversation would move on. Instead, she became visibly upset--indeed, I had never seen her upset. I apologized quickly and we let it drop.

Seems her parents must have prefered the generalized racism of Americans to the specific racism of their own country ;)