Deceptive behaviour and instrumental violence among psychopathic and non-psychopathic violent forensic psychiatric patients

Deceptive behaviour and instrumental violence are well-known psychopathic features and as such play important roles in the assessment of psychopathy. This study examined first, the nature of the violence committed by offenders that have been admitted to forensic psychiatric care and whether scores on the Psychopathy Checklist: Screening Version (PCL:SV), Part 1, were associated with the instrumentality of violence. Second, we examined the proneness of offenders to re-frame the instrumentality in their past violent crimes, and whether this was associated with scores on the PCL:SV. The results show that the PCL:SV, Part 1 (interpersonal/affective features), was positively related to the officially coded instrumentality of the violent crimes. As expected, this association disappeared when the instrumentality was self-reported. However, the majority of the patients tended to exaggerate the reactivity of their violent crimes when it was self-reported, indicating that most offenders, independently of level of psychopathy, used deception when questioned about the characteristics of their past violent crimes. The reasons for, and implications of, the use of deception are discussed.