If you're interested in the tension between biological and social identity, this discussion is fascinating:
The Left Hand of Darkness by Julian Vigo
These Are Not the Radicals You’re Looking For by Dorian Adams
It inspired this question: Are you entitled to claim a social identity if you reject the one you were raised with?
For transfolk who want to be accepted as full members of the gender they feel they belong in, the answer is "yes".
But I reject whiteness. Does that mean I get to identify as black and have the black community accept me as black? If not, would I get to identify as black if I used drugs to darken my skin like John Howard Griffin did to write Black Like Me?
Should white, black, or Asian people who feel they are American Indians be accepted as American Indians by American Indians? Groups like the Seaconke Wampanoag think so, but the Cherokee Nation’s Fraudulent Indians Task Force disagrees, saying, "False tribes distort genuine Indian history."
Who gets to decide who belongs in a social identity? My answer is that's up to the people who were raised in that social identity. Rejecting a social construct that had been imposed on me doesn't give me the right to claim someone else's.
But it does give me the right to claim a new one.
And better yet, it gives me the right to live without claiming any, to simply be a human among humans. Why agonize over which social identity fits you? Reject them all. Sex and skin color are biological, but gender and race are equally artificial—in the terms of my favorite religion, they're granfalloons. Rejecting them is hardly a new notion—for a two-thousand-year-old example, see Galatians 3:28.
Standard notice: Lest anyone think I'm dissing transfolk, I'm not. What adults do with their bodies is their business. Everyone should be equal under the law and treated with respect. Body modification is a human right. My question is purely about social identity.
Possibly related: Der Indianer: Why do 40,000 Germans spend their weekends dressed as Native Americans?
Real Indians and wannabes, and American Indian or Native American
ETA: This continues in A note to Roz Kaveney about trans identity: new identity is not erasure.