For me, knowing WHY won't make a big difference in my dressing but I am very curious nonetheless.
Scientifically, there is a lot we do know about gender issues and there are things we do not know. It is well known that many characteristics related to sex arise in response to spikes of hormone levels during particular windows of time during development. Relative levels of feminization or masculinization can result from genes (that encode hormone synthesizing enzymes and hormone receptors), or simply developmental accidents. It is reasonable to hypothesize that issues of sexual orientation, or even the tendency to CD, may also be affected by such factors. Enviromental (i.e. social) factors probably also play a role. Right now there is not a lot of compelling evidence to to explain these particular attributes one way or another.
However, we should not assume that science CANNOT explain these things, rather that the explanation is not YET known. It may never be known, but I don't think that justifies abandoning science altogether. I'll continue to be curious.
That's just me,
Love,
Brenda