That's a very good point! Seeing as gender isn't something tangible, I would have to say that perhaps that imbalance is what causes our gender! Like for instance, transgender people have the physical brains of the opposite sex, that's a pretty big imbalance right there! This is also the reason I started out by taking hormones "to try it out". I had heard that taking hormones was a pretty reliable test to see if you were trans because if your brain started to receive the wrong hormones than you would feel what a trans person REALLY feels like. I hope that's a good answer! Thanks for being curious :)