I guess my point is that if we make it a law that trans men and trans women must be treated indistinguishably from biological men/women under all circumstances, that even more bias in favor of biological males is going to creep into society anywhere physical strength or endurance matters (sports, military, manual labor, search and rescue, firefighting, etc.).

I think it's totally acceptable that your success in those areas (with the possible exception of sports, i.e. due to weight classes) should be determined by your performance and not at all by your category. After all, it sounds absurd to even point out that there are no welterweight wars.

Possibly. A few other hypotheticals:

Do you think a biological male would be tempted to self-ID as a trans woman if he thought it would give him an advantage getting into a prestigious university like MIT?

Do you think a biological male would be tempted to self-ID as a trans woman if he thought it would give him an advantage getting into a prestigious diversity-conscious STEM company like Google?

Basically, I'm just concerned that if self-IDing has no downsides and only advantages, it will be gamed to the detriment of biological females.

Diversity-conscious admissions/hiring is essentially about trying to compensate for past disadvantages. Gender and race are used as proxies, but they're obviously lacking in many ways (the woman's parents could have both been engineers, she could have been surrounded by pro-STEM culture, the native pacific islander could be a millionaire, he could have been to the most expensive private schools in existence) - so I think the right thing to do would be to detach disadvantage estimation from narrow self-reporting and base it on credible signs of disadvantage, like growing up in a neighborhood with a lot of crime.

That's probably never going to happen, though - anything that cut across the real lines of advantage and disadvantage would mean the Google executives establishing the policy would be hurting their own kids the most.

> Do you think a biological male would be tempted to self-ID as a trans woman

Tempted to? Yeah, sure. Actually go through with it—identify themselves to others as a woman, live as a woman, and so on? Probably not. I don't think many could pull it off. And if you messed up, boom, fraud—out the door you go.

Couldn't you just self-ID to one gender, have your cake, self-ID back to your original gender and eat it too? It's not like there's a centralized record enforcing your gender. It's all the honor system. In this day and age you just declare your new gender/preferred pronouns/preferred name on Twitter and that's that. No prescription from a doctor, no legal name change, nothing. Just a tweet and you are done. Nothing is falsifiable.

> Couldn't you just self-ID to one gender, have your cake, self-ID back to your original gender and eat it too? It's not like there's a centralized record enforcing your gender. It's all the honor system.

No, I don't think you could. There's a certain assumption of good faith on the parts of the people you interact with—but once you demonstrate that you aren't acting in good faith, I'm not sure why anybody would believe you, or keep you around.

> No prescription from a doctor, no legal name change, nothing. Just a tweet and you are done. Nothing is falsifiable.

That's kind of like any sort of fraud—when you're applying for a school or a position, you can make up all sorts of things about yourself. If that's the route you want to go, I'm sure there are easier things to lie about. Just—don't claim that you invented post-it notes.