Defining Alters in Multiple Personality
According to psychology, trauma to someone inclined towards dissociation as a defense mechanism results in dissociative identity disorder -- splitting the psyche into "alters" (term from the psychological community when multiple personality disorder was introduced, a term not always preferred by multiples) or "others." Also sometimes called "splits." Compare this with the term "residents" which includes alters or splits. Alters may be called "residents", "myselves", "the people inside me" or "the people in my head" by the multiple.
When someone who is dissociative is confronted by unbearable circumstances -- usually those that occur in traumatic situations -- they have a chance to split into multiple people, one of whom usually avoids the trauma while the other one takes it. Splitting is incredibly complicated and doesn't always happen due to trauma, especially after the initial circumstances in which someone dissociative splits, when it can become a matter of choice or habit rather than the best alternative to unpleasant circumstances.
Alters from the same source may be quite different from eachother, however sometimes their common roots are very obvious. One basic premise given to this concept from psychology is that, since in psychology *all* residents are viewed as alters/splits, there must therefore be a core personality, who is not usually the host personality, and the residents may all be coerced to re-merge into a single person during a process called "integration". Not all multiples believe that everyone in their head is from the same core person, that there's a core person at all, or that integration is even possible for them.
Please note: There is a great deal of contention about whether initial splits can be caused by non-traumatic circumstances, whether people may be "born multiple" and whether people may simply invite people into their head (channeling) without ever having split. All of these may be possible. The explanation common to the field of psychology is only one of many and explains the terminology and the assumptions behind treatment rather than creating a "this is how it happens" expectation for multiples.
Terminology you may encounter
Past Life split - someone who has split along lines of separate past-lives (ie. "past-life split") -- similar to a "form" split.
Form split - someone who has split along lines of separate forms i.e. someone who had once had several past lives (say as an elf, a dragon and a vampire), but now each of them are separate functional persons in the system, even though they are of the same reincarnation lines...they are separate but may share a soul.
the trauma model of splitting -- someone who has split along lines of functionality, often (but not always) in response to traumatic events. This is the typical psychological definition of multiplicity as defined above.
Is it not possible for someone to split in response to traumatic events along past-life/form lines? How does one differentiate? Should they bother?
I believe I split along past-life lines in response to traumatic episodes of sexual abuse by my father between the ages of 3-4. I was aware from at least kindergarten age (after the abuse) that I wanted to be a boy instead of a girl. As I got older, I realized that my primary image of myself in my head was that of a very sensitive, gentle, artistic boy. As a young teenager, I found myself unconsciously and then consciously identifying with male homosexuals, to the point where after going into a reverie while reading a book about teen sexuality that discussed a young homosexual male's problems grappling with his orientation, I was surprised to remember that I was not in fact a gay man.
Later in life I had a past life reading in which I was told that I was in fact a gay man in a previous life that was itself very traumatic. I immediately recognized this past life personality as the personality that had been living in my head since childhood, and began to identify with him more and more now that I was able to begin to recall more of his history and a name.
I now find myself switching back and forth between my adult female identity and this gay male identity -- not to the degree of losing my current identity entirely, but he does have a whole different constellation of emotions and memories that I can slip into at will, or not at will if I am triggered. I do experience phantom body parts, intense emotions tied to events from the past life, etc.
I am currently struggling on how to incorporate this identity into the other aspects of my life.
Recently, writing about my experiences with past life recall, I was immensely triggered and have been having trouble controlling my activities in present-day situations. (My past life alter is addicted to gay porn, possibly because he was sexually abused and currently has no satisfactory physical outlet for his own sexual expression.