There is absolutely no evidence that gender is innate, and is formed in the womb. Any neurologist will tell you that it is impossible to tell the difference between the brains of a new born baby boy, and that of a baby girl. It is more the brains being soaked in our gendered world that creates differences as humans grow and navigate human society.  As we get older, hormones play a role as well, but girls are not born liking pink and boys are not born liking blue.