In the post below Zach had a strange, though plausible, comment about how religious differences within South Asia may loom larger than differences which are substantively larger on a host of characteristics. For example, the preference for a Lutheran Finnish daughter in law for a Punjabi Muslim man than a Hindu or Sikh Punjabi daughter in law. I’m still mildly skeptical about this proposition, but I’m not as embedded in a FOBy/”ethnic” subculture as Zach is, so I can’t disagree too strongly. It is also entirely plausible from the media I’ve seen; there was a scene in Bend in Like Beckham where Parminder Nagra’s character notes how angry her parents would be if she dated a black or Muslim boy. There’s a lot of negative history here, and to some extent it seems that various South Asian groups sometimes define themselves by negation (what they aren’t), than what they are.
Another aspect of South Asian identity is the fixation on foreign origins as markers of distinction. Zach alluded to it below. Muslims are explicit about it, with a focus on their Middle Eastern (hypothetical origins). But I’ve heard plenty of high caste Hindus talking about possible Persian origins for their group, due to their light skin and features. And of course there is the constant degradation, usually implicit, of South Indians, to the point where people from Andhra Pradesh take pains to point out that they’re not Madrasis!
All of this is ironic. Because you know what they call South Asians outside of South Asia, no matter your nationality, caste, or shade of brown? Indians! Own it.