though no such thing as a male or female brain has ever been described, there are numerous genes and structures in the brain associated with gendered behavior and sexual attraction. Gender is a nature and nurture thing togethe r . we're born with certain potentials and then we build our identities according to the cultures we live in
Maybe you mean sex? There are two natural sexes and some people feel severe psychological distress at having a sex they don't like, kind of like transracial people who feel severe psychological distress at being a race they don't like or transdisabled people who intentionally cripple themselves because they feel severe psychological distress about not being crippled.
there are three natural sexes. intersex people don't like to be erased.
one theory about those particular psycho neurotic behaviors, as well as others, is that they result from past life experiences leaking into our conscious minds.