[the_omegist]

> And, I'm pretty sure this is true everywhere. In a highly competitve place (mostly due to population), they'll say something like, "he's from the janitor class, but thats okay, because he's a doctor" to justify marrying outside the caste.

Well, I don't think there is a concept of "janitor class" "everywhere"...

Of course social classes exist everywhere, but I think your example just shows what a caste system is : if a son-of-janitor becomes a doctor the in-laws in most modern societies will see a doctor, whereas in a caste system they will see a (son-of-) janitor.