In the last few decades, the incidence of Dissociative Identity Disorder (DID) has risen significantly. Most research into the aetiology of DID suggests that among other factors, a genetic propensity to pathologically dissociate is present in the development of the disorder. This thesis rejects the "innate predisposition" model of DID and aims to reconceptualise the disorder as an improvised social solution that is activated when external support structures are eroded. Insecure attachment, interrupted identity development and the acquisition of protective mechanisms are all identified as critical factors that, in the presence of trauma, lead to susceptibility to dissociate. The model put forth in this thesis postulates that DID is activated as an autodefault solution in the event of complete systemic psychological collapse. The improvised social solution is multifunctional, providing the illusion of order, the facility for conflict resolution and the provision of an internalised support structure.