Sex differences in gaze patterns while viewing dynamic and static sexual stimuli

Faces and bodies serve as important cues of physical attractiveness and reproductive fitness. Previous studies however indicate that there are sex-related differences in the visual processing of erotic stimuli. Here we measured eye movements from 43 male and 67 female subjects to investigate gaze patterns and sex differences during perception of dynamic sexual scenes (intercourse; Experiment 1) and static (nude and clothed men and women; Experiment 2) erotic stimuli. Dwell times were longest for faces in both experiments and faces were most likely to be looked at first. In the video experiment, male participants looked more at female chest, buttocks, and genital areas while female participants looked more at male faces. In the picture experiment faces received more fixations when stimuli were clothed, whereas fixations on chest and genital areas increased when the stimuli were nude. Our results show that i) sex differences during sexual perception are larger for static versus dynamic stimuli, ii) that faces are prioritized over sexual signals both while viewing dynamic sexual scenes and static images of humans, and iii) that visibility of sexual cues increases saliency of the sexually relevant body regions (genitals; chest). The overall preference for faces even when viewing sexual intercourse may reflect both the importance of facial characteristics in mate selection as well as the role of facial expressions in evaluating partner satisfaction while having sex.