I don't think there is such a thing as "Normal". We are all different and think differently. So if you want to say something like that maybe average would be a better term.
In some ways I would like to see it out of the DSM book, but only if you were able to get your meds without it being in there. True, I don't feel ill nor do I feel crazy (well?) but, like my therapist told me on my last visit with her, "Your just a normal woman". Maybe she should have said average woman. I have always, even in my most male position, have felt female. I don't think there was a minute in my life that I didn't think that I wasn't a female. I was always trying to be a male. It didn't work. I went crazy.
I really think it has to do with our brains and I would think that it is physical. I really believe that a transexual and an intersexed person are the same. No, we didn't have the outside features of the opposite gender, but in the brain we did. Being intersexed was something that was on the outside of your body, something that doctors can see. I really think that if they had a way of probing the brain, they would be able to see that we have female genitalia and in the case of FtoM they had male genitalia in their brains. Our brain runs the show, we are what the brain says we are. For most of us, we have known who we are since we were very little before we even knew a difference. We probably knew when we were in the womb, but who remembers back that far. I believe it is innate and not learning. This has had to have happened while in the womb or during conception. I will never know and I don't care to know. I know that when I came out of the operating room and woke up, I felt whole and right for the first time in all of my life. I felt a great relief. No, the hormones never did that for me, only to make me feel that I'm on the right track, even when I got rid of my testosterone via orchi. did I feel complete. It was making a vagina and feeling right with the world did I feel whole.
So I would have to say it is all physical with in the brain.
Sheila