That example has a lot to do with homosexuality. Children who say that they were not supposed to be the sex they were born as usually come out later in life and announce that they're gay.
Ok, for the sake of the argument, if people were "born" gay, then where did they get their "gay" DNA at - since "true born gay" homosexuals would never reproduce offspring?
It could never be a trait that could be handed down. Plus, they never can ever seem to find this "gay gene" they talk about so often. It's because it was never there to begin with.
People can choose to cultivate their masculinity or femininity but if G-d made them a man, then it is their job to cultivate their masculinity. It's part of their purpose. To do the opposite would make that person miss out on what life is supposed to be about (especially with children who should have both the masculine and feminine role models to grow up with in order to be mentally healthy).
That, I don't know, Schlomo. After all, as I mentioned before, my dad was gay. But then again, when I was a little kid, around 9 and after being sexually molested for 4 1/2 years at that time, I decided I liked girls because I thought they were less threatening than my uncle (who I thought of as a representative of every evil man). I don't think it was engrained in me to like girls as a child (I found out my dad was gay when I was 13), so there was no direct correlation. I think I liked girls because of the abuse and the fact that I linked the abuse to all men.
With that said, I don't know if there is a gay gene or not. But from what I do know, from the lesbians and gay men I knew in my life, some were born that way, some became gay because of circumstances beyond their control as children. Only God knows for sure. I'm just offering my opinion.