Alter Personalities in Dissociative Identity Disorder: Artefacts or Authentic Entities? Re-Evaluating the Available Evidence
An enduring debate has undoubtedly existed with respect to the legitimacy of Dissociative Identity Disorder (DID). While some contend that authentic dissociative experiences are supported by strong associations with a history of childhood abuse, others argue that the purported dissociative experiences are identity enactments sustained and reinforced by states of extreme suggestibility and fantasy proneness. However, the combination of theoretical speculation and empirical findings has thus far failed to provide unequivocal evidence for the existence of alters as either metaphors for different emotional states or truly autonomous entities that are capable of willful action. This article reviews the available evidence from a number of investigations examining the memory performance, behavioral manifestations, and physiological profiles of alters in DID. It concludes that neither memory studies nor psychobiological studies have delivered compelling evidence that alters of DID patients exist in a factual sense. It moreover demonstrates that some studies have suffered from methodological weaknesses, while findings from the overall body of literature are open to multiple interpretations. As such, they do not refute an interpretation of alters in terms of metaphors for disparate affective states. Recommendations for future studies aiming to investigate the phenomenon of alter are discussed.