It's interesting for me to read the responses to this thread. To clarify, I have no problem reducing gender to a mechanistic of biological functionalist perspective. I view gender and all other manifestations of personality, as an emergent function of neural complexity.
My challenge is with society at large, which I feel relies on dualistic metaphors (two-spiritness, man in a woman's body, etc) to explain (and, by extension, guide response) to trans issues. I'm just saying that, in the larger social discourse, it's time to move beyond metaphors.
Maddy