Sure, but the ability is less likely to come up in play if they're trans, though, isn't it? They're likely to settle on the form they're comfortable with and stick with it, just like the cis elves with the blessing.
Assuming they’re binary, sure, but there’s a lot more to the gender spectrum than cis man, cis woman, trans man, and trans woman. A genderfluid person is still trans. A bigender person is trans, even when they are in a gender state that coincides with their assigned gender.
Heh. Ask a sociologist what gender is, and they'll say it's cultural. Ask a neurologist what gender is, and they'll say it's neurological. Ask a psychologist what gender is, and they'll say it's psychological. Ask an endocrinologist what gender is, and they'll say it's hormonal. Ask a linguist... okay, they'll think you're talking about something else entirely. My point is, this kind of reductive analysis has never seemed satisfying. The human brain is a big giant crazy ball of interconnectedness. Nothing is independent.
But ask a trans person what gender is and they’ll say it’s a part of their identity. There is no doubt that neurology, psychology, hormones, culture, and a whole lot of other factors go into forming a person’s identity. But ultimately, when a person’s identity as it relates to gender does not match the one they were assigned at birth, that person is transgender.
This raises all sorts of questions about what gender actually is. I cracked about the linguist earlier, but grammatical gender (and grammar is where the term "gender" originally comes from) really does take forms that have nothing to do with masculinity/femininity. A language might, for example, divide its nouns between living things, artifacts, and natural objects. But if a human(oid) society did something similar with its members -- say, rich vs poor, or rural vs urban -- it would be a stretch to me to call that a "gender system". The first term to spring to mind would be "class system" or "caste system". Are those really the same thing as gender? Interesting to think about.
It is definitely interesting to think about. To draw a parallel to another fictional universe for a moment, one of the things I loved in Destiny’s lore (I know, I know...) was the way the Krill (a species that eventually became the enemies known as the Hive) treated gender. Their species had a 10-year life cycle, and were capable of multiple different metamorphoses after 5 years, with the specific metamorphosis depending on certain external factors like if they ate Mother Jelly (and Mothers could actually live longer than 10 years). All Krill larvae are referred to with “she/her” pronouns, as were Mothers, but Knights and Kings were referred to by “he/him.” The Lore went into the backstory of one of the series major villains, who started out as a Krill larva , and is referred to as “she” in the Lore until the point in her backstory where she takes on the King morph, from which point on he is referred to as “he.” Now, I would absolutely consider that a gender system, and it does contain an element of social class (though admittedly not economic class, and it also contains a bilological element.) I would say that
if Aurash (this character’s original name) had identified as the Krill’s equivalent of male, or Auryx (the villain’s adult name, chosen after taking on the King morph) had identified as their equivalent of female, I would consider them trans. Interestingly, later on Auryx acquires a McGuffin that gives him crazy space magic and he changes his name to Oryx, marking it as a transformation metaphorically equivalent to his earlier physical metamorphosis from larva to King. If he had at that point started using she/her pronouns, I would have considered him trans as well. Shame Bungie didn’t take advantage of the opportunity. Anyway, my point is, I would consider trans-ness a matter of having an identity that lies outside of what one’s society dictates their gender “should be,” by whatever definition that society has for gender.
At any rate, fascinating stuff. Thank you for an engaging and respectful discussion!