While the accepted answer seems to be "don't ask" -- the researcher in me wants to improve the corpus of knowledge in the world.
If you were hypothetically providing a quality of service that would genuinely be improved be asking for this information, a way could be as follows:
- Optional
- Dropdown
What's in the dropdown is what makes it interesting: Whereas the 3 major "race" descriptors are serious trigger words, the "subrace" descriptors have a level of granularity that makes it more interesting (without using the C, M or N words) and potentially less judgmental.
Aryan
Semitic
Hamitic
African Negro
Khoikhoi
Melanesian
Negrito
Australoid
Dravida & Sinhalese
North Mongol
Chinese & Indochinese
Japanese & Korean
Tibetan
Malay
Polynesian
Maori
Micronesian
Eskimo
American
Also this level of granularity, being more technical implies that it will be used for a technical purpose.
People are generally obsessed with themselves and may not even know what sub-race they are yet have a curiosity, so in that spirit provide the information.
Also the time to ask for this is the first time that a diagnosis is being asked for. This both:
- confirms that you're asking for technical reasons.
- is asking at a time when a service is expected to be returned.
Note: the more interesting question to me is that personally I'm straight-up 50%/50%* ... how do you handle that?
*moreover I just learned what my non-obvious half actually is!