"healthy multiplicity"

Some people who experience themselves as being two completely different people in one body—not just in the sense that they sometimes feel masculine and sometimes feel feminine—also use the term "bigender" to describe themselves in the event that the two people are of different genders, one male-identified and one female-identified. In this situation, at times when the person who is of the opposite gender to the body sex is dominant, they may experience similar feelings to a transsexual.

This phenomenon is sometimes seen as a kind of healthy multiplicity, that is to say, where a person has experiences similar to those described in dissociative identity disorder (also known as multiple personality disorder), but is able to come to terms with it, usually with the two people being aware of each other and cooperative, and does not wish to be seen as having an illness.