Current Issues Related to the Assessment of Sexual Deviance in Special Sex Offender Populations

The assessment of sexual deviance among sex offenders represents a mature and robust field of study, and yet there are particular offender populations that have received relatively little empirical attention and that were the focus of the current project. The present studies were archival in nature and utilized offender data from the Regional Treatment Centre (RTC) in Kingston, Ontario. Participants were adult male federal sex offenders who had been referred to the RTC for intensive sex offender treatment. As a requisite component of the program, participants completed a standardized assessment battery which included interviews, phallometric testing, and the administration of various psychometric instruments. Study 1 examined potential differences in phallometric responding based on participant ethnicity and phallometric stimulus type (i.e., visual or auditory). It was found that both White and visible minority offenders demonstrated greater deviant responding to auditory stimuli relative to visual stimuli, with no other significant differences in responding based on stimulus type between the two groups of offenders. These results suggested that both White and visible minority offenders were likely able to imagine their ideal victim when being exposed to auditory stimuli, which may have been influenced by a variety of victim characteristics including, but not limited to, victim ethnicity. Study 2 examined potential correlations between social desirability, IQ, and phallometric responding. The majority of the study hypotheses were not supported, although there was some evidence for the influence of social desirability on phallometric responding. Overall, the results of the study demonstrated the effectiveness of using differential and/or ratio transformations of penile plethysmography (PPG) data in order to accommodate the influence of extraneous variables on phallometric responding. Finally, Study 3 examined the influence of age on phallometric responding and the utility of an alternative measure of sexual deviance, the Multiphasic Sex Inventory (MSI). Age was generally found to be negatively correlated with phallometric responding, and as with Study 2, the results illustrated the importance of using PPG data transformations in order to control for the effects of variables such as age. The study also offered promising findings for the utility of the MSI as a measure of sexual deviance. Strengths, limitations, and implications are discussed