Simulation of multiple personalities: A review of research comparing diagnosed and simulated dissociative identity disorder

• Twenty studies compared people diagnosed with DID to individuals simulating DID.
• Aspects of symptoms, identities, and cognitive processes differed between groups.
• Interidentity transfer of information occurred at similar rates in both groups.
• Several methodological improvements are needed in simulation research.

Dissociative Identity Disorder (DID) has long been surrounded by controversy due to disagreement about its etiology and the validity of its associated phenomena. Researchers have conducted studies comparing people diagnosed with DID and people simulating DID in order to better understand the disorder. The current research presents a systematic review of this DID simulation research. The literature consists of 20 studies and contains several replicated findings. Replicated differences between the groups include symptom presentation, identity presentation, and cognitive processing deficits. Replicated similarities between the groups include interidentity transfer of information as shown by measures of recall, recognition, and priming. Despite some consistent findings, this research literature is hindered by methodological flaws that reduce experimental validity.