Classification of Child Molesters by Plethysmographic Assessment of Sexual Arousal and a Self-Report Measure of Sexual Preference

Abstract

The present study examined the extent to which the use of multiple measures of pedophilic interest improved on the diagnostic accuracy of any single measure. Seventy-two child molesters completed a self-report card-sort measure of sexual interest, as well as direct monitoring of penile response (penile plethysmograph-PPG) when presented with erotic slides or audio material. The reliability of all measures was high (alpha .91-.96). All three measures of pedophilic interest (i.e., card sort, PPG slides, PPG audio) significantly differentiated boy-object (n = 20) and girl-object child molesters (n = 52). The card-sort measure showed the greatest classification accuracy and was the only measure to significantly improve accuracy, once the other two modalities were considered. Consideration of all three modalities provided classification accuracy (91.7%) greater than any single measure.