Psychosexual characteristics of sexual offenders and the relationship to sexual reconviction

Abstract

The purpose of this study was to determine if the Multiphasic Sex Inventory (MSI) could be used to predict sexual reconviction. The MSI was administered to 119 convicted male sex offenders. Reconviction data were analysed using the receiver operating characteristic (ROC) over 2-, 5- and 10-year follow-up periods. The MSI scales Sexual Obsession and Paraphilia (Atypical Sexual Outlet) obtained good accuracy in predicting sexual reconviction over 2- and 5-year follow-up periods. A confirmatory factor analysis of the MSI scales yielded a four-factor solution: Sexual Deviance, Sexual Desirability, Dysfunctional/Justification, and Normal. The Sexual Deviance factor demonstrated good accuracy in predicting sexual reconviction at 2-year follow-up while the Normal factor was a poor predictor of sexual reconviction. Compared against an actuarial risk assessment measure for sexual offenders, the Sexual Obsession, Sexual/Social Desirability, and Sexual Dysfunction scales, and Sexual Deviance factor made a statistically significant contribution independent of the risk scale in predicting sexual reconviction. It is argued that rather than using the MSI solely as an assessment measure of psychosexual characteristics of sexual offenders in treatment programmes, it can be used to provide additional information as part of an assessment of risk of sexual reconviction.

Keywords:

• Sex offenders
• MSI
• sexual reconviction
• predictive accuracy
• receiver operating characteristic

Notes

1. A perfectly accurate test would yield a ROC hit rate of 1.0 (no overlap between recidivists and non-recidivists) whereas an index of 0.50 indicates prediction no better than chance. The “curve” for a perfect test would travel up the vertical axis then along the top of the box until it reaches the top right-hand corner. A diagonal line represents an index of 0.50.