I'm not sure I want to "wade into" the murky fluid of "trans and gender issues. Some people believe that, contrary to appearances, they are not the sex they were "assigned". First of all, "sex" isn't "assigned at birth"; sex is
identified, based on readily apparent organs. Sometimes, (not very often, .001%) genitals are too ambiguous to make a visual determination. [The term "assigned sex" is employed to support the ideological notion that the identity of male or female is arbitrary.]
Not at all unreasonably or inhumanely, babies are raised to be the sex their unambiguous genitals say they are. More to the point, the genitals are a result of the DNA which has directed a male or female body to exist.
How people
identify themselves in the body they are born with is more complicated then which gender roles any given person performs. As a gay man, I prefer sex with other men, but I have no inclination to think of myself as a woman, or to behave like a woman. Some homosexuals do think of themselves as their opposite sex, at least some time. There are heterosexual men who prefer sex with women who like to behave like women, at least some of the time -- cross dressers. It's quite literally "role play". Some women like to play the same game, dressing as men.
It seems to me that "transgendered people" have adopted an extreme form of homosexual drag, one in which they commit to playing their opposite gender role all the time, and making changes to their body to match their concept of the role. So, for some it is a matter of changing costume and hair. For others, it involves an extensive re-upholstering of their body,
I believe their are limits to this game. One can have the opposite's genitals constructed; one can take hormones to shape the body. The appearances can be changed. But, after all that, one remains one's biologically determined sex.
It's a game of appearances, and as Oscar Wilde said, "It is only shallow people who do not judge by appearances. The true mystery of the world is the visible, not the invisible."