Heterosexual, Homosexual, and Bisexual Men's Pupillary Responses to Persons at Different Stages of Sexual Development.

This study investigated whether pupil size during the viewing of images of adults and children reflects the sexual orientation of heterosexual, homosexual, and bisexual men (n = 100, Mage = 22). More specifically, we explored whether this measure corresponds with sexual age preferences for adults over children in nonpedophilic men. In general, results across three experiments, in which observers freely viewed or rated the sexual appeal of person images, suggest that pupil dilation to sexual stimuli is an indicator of sexual orientation toward adults. Heterosexual men's pupils dilated most strongly to adults of the other sex, homosexual men dilated most strongly to adults of the same sex, and bisexual men showed an intermediate pattern. Dilation to adults was substantially stronger than dilation to younger age groups. Sexual appeal ratings for images of adults and children also correlated with pupil responses, suggesting a direct link between pupil dilation and sexual interest. These findings provide support for pupil dilation as a measure of sex- and age-specific sexual preferences