I want to point out this: many transphobes will claim that misgendering is essentially harmless. When I point out that trans people who’re repeatedly misgendered have significantly worse mental health than cis people, transphobes double down and claim that:
Misgendering is harmless. Evidence: cis people who are misgendered aren’t negatively effected.
If a harmless thing causes you mental suffering, that’s because you’re mentally ill.
Trans people suffer when they’re misgendered.
Therefore, trans people are mentally ill. The problem is their transness, not misgendering.
I have a method to destroy this transphobic argument: attack the first premise. Specifically, I claim that misgendering a cis person harms their mental health. (And yes, there IS evidence indicative of this.)
Transphobes usually respond with something along the lines of “You’re wrong, I was misgendered and I came out fine!”. To which I answer: “You’re comparing yourself - who got misgendered a few times, very rarely, by people who then corrected themselves; with trans people who have been repeatedly misgendered for pretty much their entire life, by a lot of people. That’s not a valid comparison.”
Then I offer the transphobe a solution: “I have an idea for an experiment. We’ll take some little cis kids, and we’ll misgender them repeatedly for their entire childhood, just like trans kids in transphobic environments are repeatedly misgendered throughout their entire childhood. Then we check the kids’ mental health. If the kids are significantly affected, it means that misgendering is harmful to EVERYONE, cis or not. What do you think?”
At this point the transphobe will claim that what I’m proposing is basically child abuse. Which implies that misgendering would be harmful to cis kids.
Which means that their entire transphobic argument - which hinges on the premise that misgendering is essentially harmless, and that only non-cis people are negatively affected by it - falls apart.
(No, I wouldn’t actually do or promote that experiment.)