Sexual arousal to nonsexual violence and sadomasochistic themes among rapists and non-sex-offenders.

Twenty heterosexual rapists, 10 non-sex-offender patients from the same maximum security psychiatric institution, and 10 men with low socioeconomic status recruited from the local community were presented with audiotaped narrations while their penile tumescence was measured. The story categories were as follows: female victim/partner (neutral situation, consenting sex, rape, nonsexual violence, consenting bondage and spanking, masochistic bondage and spanking, and nonconsenting bondage and spanking) and male victim/partner (neutral situation, consenting sex, rape, and nonsexual violence). There were no differences between the two non-sex-offender groups, and they were combined. Rapists showed more sexual arousal to rape descriptions and less to consenting sex stories than the control subjects. As predicted, rapists were sexually aroused by stories involving nonsexual violence with female but not male victims. Surprisingly, there were no differences between rapists and control subjects in their responsiveness to the spanking and bondage stories. It was concluded that the amount of violence in the rape descriptions is critical in differentiati ng rapists from non-sex-offenders. A number of investigators have shown that rapists' sexual arousal patterns are different from those of non-sex-offenders (Abel, Barlow, Blanchard, Barbaree, Marshall, & Lanthier, 1979). These differences are shown most clearly by a measure of the relative amount of penile tumescence increase elicited by audiotaped descriptions of rape and descriptions of consenting sexual intercourse. Relative responsiveness to these two stimulus categories is expressed by the rape index, the average response to the rape category divided by the average response to the consenting sex category. Rapists typically show higher rape indexes than non-sex-offenders. In our laboratory, we have replicated this basic finding using different subjects and stories by demonstrating that rapists are differentiable with the rape index from (a) non-sexoffender patients from the same maximum security psychiatric institution and (b) normal control subjects with low socioeconomic status