These are some very interesting questions.
Can people have more then 2 genders at the same time, 3 or more multigenders?
Possible though less likely to be identified on a personal level. In that case where you've got more then one persona, you would probably recognize something was wrong eventually because of the change in behavior that would be exhibited from time to time. If you had one boy and one girl, you'd be able to identify for the most part which was which. If you add another boy or girl or even an androgyne persona into the mix, unless that persona opted to be distinquished from the other personas, they would just as likely be subsumed in any other matching gender personas present.
is that much more in the realm of multiple personality? Or would one say bigender is a multiple personality. Or how would it be different or similar?
The biggest difference between Dissociative Identity Disorder(Multiple Personality Disorder) or bigender is the reason for the multiple personas or personalities. Admittedly the line can seem very blurred and at the base level it really comes down to what the person experiencing it feels.
Most experts agree that Dissociative identity disorder is first and foremost a very controversial diagnosis. It is important to mention that DID is in no way related to schizophrenia. DID is probably impossible to actually prove conclusively exists though some experts would argue they've found cases that appear to confirm the existence of such a disorder. The problem lies in that there is currently no way to directly measure thought processes and so any information gained from speaking with a patient is not subjective. They could conceivably be lying or even influenced to behave a certain way just by being interviewed. Many believe it is difficult if not feasible to measure something exactly without influencing your results.
Also DID is believed to occur as a result of early childhood trauma or anxiety as well as extremely traumatic experiences as an adult. If no trauma or significant anxiety was present in the person's life, DID will not occur. Mental health experts theorize the initial split is a way for the individual to cope with those experiences in a way that allows dissociation of self to reduce the strain mentally.
That brings us to the other set of people, those who identify as bigender. This is associated closely with gender identity and much like transsexuals, they are born the way they are and not by choice, in this case with an extra spirit within. Bigender individuals may go through their life never experiencing any sort of trauma or extreme anxiety that might have caused DID. They simply live with an extra perspective within, starting to learn about themselves as early as memory allows.
Two-spirited peoples have been around for as long as there have been people. Recent terms that attempt to define us, such as transgendered or "gender dysphorics" are inadequate to describe what is first and foremost a spiritual state. Sure they are related to gender to some degree but not entirely so.
Although it certainly isn't always the case, the two are capable of not only acknowledging each other, but can work in conjunction/cooperation and in some cases even develop a deep or absolutely love for each other. In such cases, a feeling of balance and peace is present.
When it comes down to it, at the very base level, if you're ok and accepting with who you are, no amount of mental health experts or anyone for that matter can prove you wrong.
And that as they say is that.
Mia and Marq
Harmony - Balance of Opposites