Personally, a big belief of mine is that gender identity is both nurture and nature.
First off, it seems that studies show that in a billion ways, chemicals and hormones decide both our emotional and physical sex before birth. There's hermaphrodites for crying out loud! The womb is a complete lottery number, and there are facts that truly do identify every portion and probability, and the reality is that not one person ever seems to be born in the same way. We are truly all predisposed to various things way before we are are pushed out, gender identity being one of them.
However, facts also prove that beyond any possible predisposition, children pick up on the positive patterns of life as soon as they come out of the womb. A baby who lives in a family where the father is dominant and treated with most respect will recognize that pattern in just months, if not days. A baby who lives in a family where a mother or sister is treated with most dignity will pick up on that just as quickly. Children learn in just months what positive and negative patterns surround them, and they often do model themselves after what they perceive as being the most positive lifestyle; children often just are indeed more inclined to follow their instincts of patterns rather than listen when Mommy says "It's best if you just act like a boy!."
And the facts are that these patterns account for just as much a person's identity as any chemical predisposition. Stress even often plays a bigger part; the amount of stress a person goes through in life directly influences their strive and will to dig deeper into their own personality instead of simply settling with the world around them. You can dig up personality and identity in a billion different ways, both biological and psychological, and really, the end result is that every single person is different (some more than others) and that there is no reason to discriminate against anyone. We truly are all different in at least one way, and no one would want to be hated for that difference.
Now, GID tends to be classically defined as a person who has a strong dislike of their genitalia, and by classic definitions, GID relates to the syndrome where a person wants a limb to be amputated. The classic definitions make it sound more like a body-part problem, and not an identity problem. However, I believe that most current sources use a definition that describes a person who wants to identify as female socially and aesthetically, not just a genitalia dysfuntion. This describes a person who wants the whole picture beyond the genitalia, and in the grand scheme of money, the danger of surgery, and even sometimes a fondness of the penis, I'd say the majority of trans never go through with genitalia surgery; if they do, it's often the last thing they accomplish. Many just don't seem to let the penis, a very hide-able body part, stop them from transitioning everywhere else, both socially and aesthetically. It's actually very healthy when dysphoria gives way to a detailed and planned-out realism.
And then of coarse, some of us just plain out want to identify as a girl in 99% of our looks and social life aspects, but somehow just plain like having a penis, and some of us enjoy being androgynous, where we can "switch" back and forth from a female and male role quite miraculously. I believe all these variations are equal and very healthy, and that the only problem with the more surgically-or-hormone based side of gender identities is that surgeries and hormone effects are most of the time hard or even impossible to reverse. By definition, it can truly be more realistic to put off any type of surgery or change until one knows that they've tried every alternative way to be happy, but then again, I also am a big advocate that many times surgery or hormones are indeed needed to allow one to both improve or even begin to fit into a male or female role. I know 100% that the majority of the folks out there need a jumpstart, a sign, an improved look.
In terms of facial surgery, I oftentimes support the changes that give a person a more androgynous facial image, an image that will not extremely hinder a male nor female look. I do have to say I'm biased toward believing that every single person is truly predisposed to regretting a choice, and that if that ever happens, it's a miracle when the changes you've made just haven't been too far to either side. I have studied androgyny extensively and many studies come to the conclusion that androgynous peoples tend to have the most freedom in which lifestyles, identities, and careers they can freely choose in a subconcious or physical manner, which tends to result in the least stress and an overall higher rate of happiness than people whom are forced to conform from an early age to a certain gender role or attractiveness level. A good example of this is actor Cillian Murphy, who is known for his chameleon-like roles, playing downright sexy and beautiful transgenders all the way to masculine serial killers. He's the type of guy who could literally be any gender or personality he wanted to be, no fuss. This type of person tends to be most confident and successful in most real-world scenarios; the reality is that no one wants to be stuck in a place they can't get out of. The same goes for absolutely any life choice, I just believe it's "wise" to step into anything with caution, doing minimal steps first; steps that simply create balance, steps that test the waters.
However, that's a bit off subject though, the genitalia is a bit different than the face or body, and the identity with it, well, is more "black or white". However, the audience of the genitalia is not; there are men who like ladies with penises, there are men who like men with vaginas, there are men who like men with penises, and there are men who like ladies with vaginas. There's really a big sexual following with each individual category, as strange as the category may be; I wouldn't say that trans people are usually socially forced to decide on a certain genitalia. Many find partners either way, there are many strange "straight men" out there. The genitalia is truly the part that stems most of all from a person's feelings and it tends to be the person who has to make the choice on what feels right for them. The social force and judgement is usually applied more toward the face or body, but if the trans is truly someone who wants to forget their past entirely and be able to walk into any bar and pick up any straight man without him ever guessing, then genital surgery is just as much a part of the important equation!
