Bitterdregs... the research HAS progressed. Dissociative disorders are much better understood these days, and there are several prominent researchers who have come up with respected theories about how and why dissociative disorders develop. The structural theory of dissociation is the one currently upheld by the international society for the study of trauma and dissociation (http://www.isst-d.org/) and there is much information to be found at that site about recent developments in research.

The dissociative community doesn't seem to be very accepting of the latest research though, and I wonder if it is because those who are actively dissociative still have a need to maintain the belief that the alters are indeed separate entities (ie - NOT part of the self). Which of course is only natural... the primary defence is to believe that the parts are all separate entities and the experiences happened to 'them' and not 'me', so assimilating something that refutes that is likely to be too much to take in. I know I couldn't have accepted during most of my time in therapy.

I have noticed people writing that alters are *only* born out of trauma, but that is not true. Of course the initial lack of integration in the developing personality comes from some form of trauma (and it does not necessarily have to be violent or life threatening as is often believed) but once that coping / defence mechanism is in place further dissociation can occur for all manner of reasons - sometimes simply even practical ones. In the theory of structural dissociation there are two main splits - ANPs and EPs. EPs are the dissociated states that hold unintegrated emotions and trauma related events, and ANPs ('apparently normal personalities' - you'd think they would have thought of a better name!) that typically deal with regular day to day events. In some dissociative systems there may be only one 'ANP' who deals with ALL day to day activities, but in others there may be multiple ANPs, each of whom deal with a particular aspect of range of activities. For instance one ANP (alter) may be the holder of music. That may be their only job. This alter may not have been split through trauma, but become a separate state because music is triggering to the host ANP and separation was required to keep the triggered information / material away from the host.

Read up more about the structural theory of dissociation if you can. It forms the basis for the treatment guidelines upheld by the ISST-D, which informs the international community on best practice for the treatment of dissociative disorders.