cry havoc

I think as long as the questions are somewhat objectively clear -- I mean, nationality = name-on-passport, that's pretty cut-and-dried, and the options for selection make it clear that there's a wide range of potential ethnicities, then at least that much doesn't require the self-evaluation. It's when you get into whether a person self-identifies (and is externally-identified) as a privileged person vs non-privileged that, wow, suddenly gets harder. And only exponentially moreso, the more cultures you try to make allowances for.