>>>Unless you pin down what you mean by ethnicity, I can't even begin answer.

Let's go with common genealogy or phenotype.

>>>Ethnicity seems a social construction

So in the absence of society you would not be able to physically distinguish between these two gentlemen [1][2] and would classify them as the same ethnicity? You cannot discern objectively-measurable distinctions between the appearances of these two faces? Facial recognition software demonstrates otherwise. [3] Every face has measurements, which cluster with other similar faces. I doubt it would be difficult to map each of those clusters with what we consider an "ethnicity".

>>>But, maybe. After all an american indian guy decided to 'identify' as a tiger <https://en.wikipedia.org/wiki/Stalking_Cat>. While that's a very odd decision to me, I'm not going to step in and physically stop him. Would you?

Did he receive any LEGAL benefits normally given to large predatory felines? If no, then intervention isn't required. If yes, then absolutely I would oppose it. "Sticking feathers up your butt does not make you a chicken" - Tyler Durden.

>>plesse leave politics out of this, ta, it's complex enough.

Regardless of her politics, Elizabeth Warren is a public, high-profile figure and a perfect example of an American using their "internal" identity for legal gain. Rachel Dolezal is an alternative example. Both demonstrate that these aren't really hypothetical issues, but present-day issues crossing the spectrum of not only social issues but also medical and cosmetic technology (elective, plastic surgery, skin treatments, etc...).

>>>This is about people who feel they don't fit their body and you try to drag in this?

I try to keep a long-term, macroscopic view on social issues. But honestly, if I were to elaborate on my position it would be a long, kinda-rambling mess, so I'll table that point of the discussion.

>>>And why do you assume I'm from the US?

Oddly enough I'm usually fighting the same bias inherent in a US (and especially SFV/SFBA-heavy) website. I'm American but don't live there. So....touché on that one.

>>>Final question, have you ever met a trans person?

Of course. I live in Asia. Anyone who has spent more than a few minutes in a bar in Thailand, Philippines, or the bigger cities in Japan has been hit on by a trans person.

>>>Or understand what they can choose to undergo because they feel so wrong - they can go through a lot, it's not an easy thing.

Every human is operating within the restrictions of their physical form. My rackmate at OCS was a short dude (like 5'4") and years later he told me he considered leg extension surgery....the same kind that killed the guy in [4]). Short guys experience all sorts of emotional abuse and nobody really gives two shits about them either. Should my friend declare that he is 6'1" because he FEELS taller? Should we update all of his government documents and forms of identification as such? Of course not. Feelings are ephemeral, fleeting, and subjective. Step off a cliff and say to yourself "I FEEL like I shouldn't fall...I identify as a bird." Does gravity comply? No. Life is hard. Get harder.

[1]http://thewarriorfitness.com/wp-content/uploads/2015/09/Warr...

[2]https://tinyurl.com/yyoamjl4

[3]https://github.com/ageitgey/face_recognition

[4]https://news.ycombinator.com/item?id=21082702