Inhibiting Sexual Arousal to Children: Correlates and Its Influence on the Validity of Penile Plethysmography

The current study examined the extent to which 1136 men were able to inhibit their sexual arousal on a phallometric assessment, when instructed to do so. Although the observed changes between the two conditions (i.e., Normal and Suppression) were small to moderate in magnitude, the change was not more than what would be expected by measurement error for most participants (e.g., 83% of pedophilic sex offenders against children did not successfully inhibit their sexual arousal in the Suppression condition). There were very few variables that were associated with the ability to suppress. Higher Pedophilia Index scores in the Suppression condition predicted a greater likelihood of sexual recidivism among sex offenders (hazard ratio = 1.17, 95% CI [1.04, 1.32]), but the ability to suppress sexual arousal was not found to predict sexual recidivism. The current study highlights the importance of accounting for measurement error and found that, when doing so, most sex offenders against children are unable to successfully inhibit their sexual arousal to children when instructed to do so, and that the ability to suppress sexual arousal is not associated with recidivism.

Discriminative and predictive validity of the penile plethysmograph in adolescent sex offenders

The current study addresses the discriminative and predictive validity of the penile plethysmograph (PPG) in a sample of 132 male adolescent sex offenders who were admitted to a sex offender treatment program. The subjects were assessed pretreatment and posttreatment, under two different instructions sets: an Arouse condition, where subjects allowed themselves to become aroused; and a Suppress condition, where subjects attempted to suppress or control their arousal. Under the pretreatment Arouse condition, the group with male child victims demonstrated significantly greater arousal to child stimuli than the group with female nonchild victims. However, the group with female child victims could not be differentiated from the group with female nonchild victims. Under the Suppress condition, there was no evidence of discriminative validity for any of the PPG indices. As for predictive validity, posttreatment arousal to male and female children was significantly related to sexual offense recidivism. Posttreatment inability to suppress deviant arousal to male and female children was also significantly related to sexual offense recidivism over the 6-year follow-up period. In light of these findings, the implications for adolescent sex offender research and treatment are discussed.