>>40613645 (OP)It's just splitting in case of more severe manifestations, sometimes entities take advantage of this propensity in unstable individuals to mind control them. Usually well adjusted people won't have a shadow of the opposite gender unless they're truly a freak. Most people aren't even self aware enough to be suppressing anything other than the usual desires.
The people you see talking about anima/animus undergo either their own groups methods or are initiated by an entity into learning about opposite gender mental dynamics. Both to imitate, act or become more savvy/wise. There are several schools that either ascribe to the barbelo or agender soul, it's seen as completing your inner self.
I would strongly advise against all this inner alchemy stuff, it's just a fast path for some spirit to give you AGP as a joke or make you a "sleeper". You're better off reading about the opposite gender psychology or learning method acting. It's also functionally useless when it comes to pure utility if you can't pass as the opposite gender. The only exception being deceiving people online or anonymously.