Examining the differences among the MCMI-III profiles of incarcerated sexual offender subgroups and nonsexual violent offenders
Using archival data collected from subgroups of sexual and nonsexual incarcerated male offenders, this research sought to identify any clinically meaningful group differences in Axis I and Axis II psychopathology as measured by the Millon Clinical Multiaxial Inventory - III (MCMI-III; Millon, Millon, Davis, & Grossman, 2009). Statistical comparisons were conducted, first between child molesters (a subgroup of the sexual offender sample involved in this study) and nonsexually violent offenders, and then within the overall sample of sexual offenders, which was divided into subgroups based on each offender's sexual recidivism risk score (higher verses lower risk), as measured by the Static-99 (Hanson & Thornton, 2000). Additional analyses were completed to determine the ability of the MCMI-III scales in predicting group membership between the child molesters and nonsexual violent offenders, as well as in predicting offender Static-99 score. Results generally supported many of the findings set forth by previous literature. In particular, child molesters produced significantly greater mean scores than did the nonsexual violent offenders on the Axis II personality scales of Avoidant, Borderline, Dependent, Depressive, Masochistic (Self-Defeating), Schizoid, and Schizotypal, as well as several of the Axis I scales, while the nonsexual violent offenders scored significantly higher than child molesters on only the Axis II personality scales of Antisocial, Narcissistic, and Histrionic. Overall, the MCMI-III Axis I and II scales were each generally successful at predicting offender membership into these groups, and the significant contributions of individual scales are discussed further. In terms of the comparisons between higher and lower risk sexual offenders, significant differences were identified on the Antisocial and Compulsive personality scales, as well as the Axis I scales of Alcohol Dependence and Drug Dependence, and the Antisocial scale in particular was found to be associated with an increase in offender Static-99 score.