Most of the current literature on multiplicity describes it as something that involves an original personality who gets shattered or fragmented into many different pieces, each of whom is a depleted aspect of a "whole" personality. But does this model help or hurt multiples? It implies that only one fully-developed person can be held in one head at one time, and that any personality which goes on to develop a strong sense of self-identity must necessarily be lesser, a one-dimensional personality capable of only a limited sphere of behavior.
Indeed, most media and psychological literature portrayals of multiples cater to this stereotype; the different personalities are portrayed as being flat caricatures (the sexy seductress, the scared child, the tough protector) who behave not like real people but like poorly-written characters in a trite morality play. The implication is that in order to create a new identity, something must be taken away from an already-existing one.
Of course, this serves to reinforce the notion that having more than one identity is intrinsically disordered; if each one is thought of as being simply a broken part of a whole, then of course it seems as if it would be necessary to put them all back together into one, complete person. And while I believe people can indeed "split off" parts of themselves as a way of dealing with trauma, and don't choose it consciously, the "shattering" model is vastly inaccurate, as well as potentially damaging, as a universal explanation for multiplicity.
Think of the mind as being not something with a set capacity and fixed amount of raw material but as something that grows and changes over time just like the body does. Think of identities as new shoots from a plant rather than something which must remain static. They can change over time and evolve to adapt to their environment.
Maybe personalities should be compared to growing lifeforms rather than to broken objects. All humans begin life as a single cell, which, for the first phase of its existence, does nothing but replicate itself, dividing over and over until it becomes a mass of undifferentiated cells. In this phase of growth, each of the cells-- stem cells, as they are known biologically-- has the potential, if seperated from the others, to grow into a complete human being. If the original cell, when it replicates for the first time, splits itself into two independent cells rather than staying connected, each of the cells will grow into a full physical human body. Identical twins are, from a genetic standpoint, essentially the same body, but their personalities can be quite different indeed. Yet no one would suggest that it is possible for identical twins to be somehow be "put back together" to make one single person, or that they are "broken" and "incomplete."
Maybe seperate identities are not halves of a whole but merely seperate potentials, of the many inhabiting every human mind, which took different paths of development. If they do wish to be integrated, perhaps it should be seen as the fusion of seperate persons to create a new person altogether, rather than putting two broken pieces back together. Since personalities constantly grow and change and adapt throughout life, even a seperate identity which begins as a "split" can go on to become a developed personality in its own right, without any depletion. In a way, keeping different mindsets with seperate and distinct senses of identity can help to refine and specialize particular abilities or talents.
As with so many other aspects of the traditional psychological view, the "shattering" model forces multiples to pigeonhole themselves in order to be believed and taken seriously. Seperate selves cannot act like real people with nuances, moods and variations in behavior, but instead must take flat, caricatured roles-- sometimes very extreme ones-- in order for others to believe that the multiplicity is "real."
The irony in this is that it is often the most autonomous identities with the strongest sense of self who have the most fully-developed personalities, and are the best at keeping up a constant appearance and the impression of being a single self, while the less independent, task-specific selves are the ones who have more flat and predictable personalities that better fit the stereotypes. With the understanding that multiplicity is not a game or a way to garner attention and pity comes the understanding that the simple act of having more than one self can cause one to be institutionalized against their will, fired from their job, ostracized and branded insane by family and friends, and presumed to be too sick to be capable of making reasonable, mature life decisions, and consequently the need to stay "in the closet" and maintain at all costs the illusion of a single personality becomes a foremost priority.
Multiples who are self-sufficient and not part of the therapy culture (or refuse to be a part of it) stand to lose the most from disclosure, because there is no alternate model in our society. Either you accept that you're sick and need to get well, or you're "in denial" about your dysfunctionality and need to have your personal rights taken away from you in order to "help" you.
The "broken parts of a whole" model probably remains the main reason why multiplicity continues to be seen as disorder and not as a valid and functional lifestyle (and, indeed, has forced many people to repress or misunderstand their multiple tendancies). If it could just be reduced down to the simple tenet of "more than one self per body," society might even embrace it-- indeed, if psychological literature hadn't set such a precedent with the "MPD/DID" paradigm, we'd probably find whole shelves of self-help books on "discovering your other selves" in the bookstores today.
Two plants can spring from a single root, two children from a single cell. Why not two (or more) selves from a single brain?