I don't quite know if I believe that, but I do think there is some truth to it, at least. But this post is going to make me go on a tangent, so bear with me...
I think a good deal of transgenderism isn't really valid and is based on social constructs rather than biology. If a transgender person literally feels they have the wrong genitals, that's not what I'm talking about. I'm talking about say, biological men who feel they are women trapped in men's bodies because they want to wear pretty dresses, high heeled shoes, have long flowing hair, love the color pink, etc. Absolutely none of those things are inherently feminine, they are just associated with femininity due to social constructs.