Sensitivity and specificity of the phallometric test for pedophilia in nonadmitting sex offenders.

The specificity of phallometric testing for pedophilia has been calculated using sex offenders against adult women. Does the offender's actual number of prior sexual contacts with women affect such estimates? To answer this, the authors' studied 82 male sex offenders against adult women, 172 offenders against unrelated children, and 70 offenders against their own biological children or stepchildren. Phallometric testing included visual and auditory depictions of prepubescent, pubescent, and adult males and females. The results for offenders against women showed that those who had had sexual contact with the greatest number of women (consenting or nonconsenting) had the lowest probability of being diagnosed as pedophilic. Specificity, calculated for those who had sexual contact with the most women and thus the most evidence of attraction to them, was 96%. Sensitivity, calculated analogously for men with the most offenses against children, was 61%.

Fraternal birth order and sexual orientation in pedophiles.

Whether homosexual pedophiles have more older brothers (a higher fraternal birth order) than do heterosexual pedophiles was investigated. Subjects were 260 sex offenders (against children age 14 or younger) and 260 matched volunteer controls. The subject's relative attraction to male and female children was assessed by phallometric testing in one analysis, and by his offense history in another. Both methods showed that fraternal birth order correlates with homosexuality in pedophiles, just as it does in men attracted to physically mature partners. Results suggest that fraternal birth order (or the underlying variable it represents) may prove the first identified universal factor in homosexual development. Results also argue against a previous explanation of the high prevalence of homosexuality in pedophiles (25% in this study), namely, that the factors that determine sexual preference in pedophiles are different from those that determine sexual preference in men attracted to adults. An alternative explanation in terms of canalization of development is suggested.