Effects of differential rules on production of verbal behaviour associated with dissociative identity disorder in a mock legal context

Abstract

The role of rule-governance in producing verbal behaviour associated with dissociative identity disorder (DID) was investigated, using a single-factor, between-subjects design. Fifty-two undergraduates role-played the part of an accused murderer undergoing a psychiatric assessment to prepare a legal defense. Participants were assigned randomly to one of three groups, a DID rule group, a self-defense rule group, or a control group. Participants then underwent a mock psychiatric assessment. Specific verbal behaviour of participants during the assessment was analyzed between groups. The hypothesis that individuals in the DID group would demonstrate more verbal behaviour associated with DID than those in either of the other groups was supported by data from a structured interview and a self-report measure; however, a statistically significant difference among groups was observed on only one (initial denial) of six dimensions on an unstructured interview. This latter result suggests that the contextual cues and perceived situational demands associated with the mock psychiatric interview were powerful enough to overcome the effect of the differential instructions.