In one of the posts I linked to in my previous post, Eugene Volokh prints this bit of a letter from a reader:

I happen to be 40 years old, happen to be an economist, and happen to be fertile, but I AM a man. I am not a human who happens to be a man. Being male is fundamental to who I am in a deeper way than any of these other characteristics.

Kieran Healy picks up on this argument for some speculation about what constitutes the essence of one's identity, but doesn't quite get to the good stuff. For me, being a geographer-anthropologist is a more fundamental part of my identity than being a man (or being 22 years old, or [presumably, though I've never put it to the test] being fertile).

The underlying idea in discussion of this quote seems to be that those things that are inborn are more fundamental to the person's identity. It's logical in a way, because those characteristics seem more permanent. But when I think about my own self-image, it doesn't work that way. This may be the existentialism in my worldview showing through. The most important parts of who I feel I am are not the things that I have no control over, like sex or age. Those just happened to me. The important parts are the parts I work for -- my skills, my profession, etc. I am who I make myself.

This gets somewhat more complicated when we consider gender as opposed to sex. Gender is something that is made, rather than inborn, though it often partakes of the feeling of fundamentality that sex has, when social characteristics get linked to biological ones. Being a man isn't terribly important to me -- indeed, I feel a bit strange about even writing "I am a man." I do plenty of things that are typically male, such as being emotionally reserved. But I don't think of those things as things that complement or spring from my maleness. When I try to imagine what a female version of me would be like, I don't imagine that those things would -- or should -- change. I experience them as independent of gender and sex. Perhaps there's a bit of dominant-group privilege working there, so that I, as a male, can easily see gender as less important. Yet I know many men do see many aspects of their lives as tied up in their maleness that I would see as separate and equally applicable to a female version of myself.

Certainly a female, but otherwise identical, version of me would be different in ways I can't guess. The non-permanent aspects of identity are not strictly endogenous -- they come as well from how the world treats you and what options it has open to you. And those exogenous aspects of who you are (as well as the inborn parts) can exert a strong influence on what directions the endogenous aspects want to go. But still, when I imagine alternate versions of myself, the ones that share my aspirations and accomplishments are more "me" than the ones who happen to share my physical makeup.