Sexual motivation strongly influences mate choice and dating behavior and can be triggered by merely viewing sexually arousing visual images, such as erotic pictures and movies. Previous studies suggested that men, more than women, tend to search for sexual cues that signal promiscuity in short-term mates. However, it remains to be tested whether sex differences in the motivation to view sexual cues can be observed by using robust and well-controlled behavioral measures. To this end, we employed a pay-per-view key-pressing task. Japanese self-identified heterosexual male and female participants viewed images of men, women, or couples with two levels of sexual arousal (sexual vs. less sexual). Participants could alter the viewing time of a presented image according to their willingness to keep viewing it. Male participants were the most eager to view sexually arousing images of the opposite sex, whereas female participants were more strongly motivated to view less sexual images of couples. Such sex differences may reflect differentiated reproductive strategies between men and women in terms of men’s motivation toward promiscuity and women’s motivation toward long-term relationships.

性动机强烈地影响伴侣的选择和约会行为，并且可以仅通过观看引起性欲的视觉图像（如色情图片和电影）来触发。先前的研究表明，男性比女性更倾向于寻找暗示短期伴侣滥交的性暗示。但是，是否有能力通过使用强有力且控制良好的行为措施来观察性暗示动机上的性别差异，尚待检验。为此，我们采用了按次计费的按键操作。日本自我认同的异性恋男性和女性参与者观看了具有两级性唤起（性与少性）的男性，女性或夫妻的图像。参与者可以根据自己愿意继续观看的图像来改变其观看时间。男性参与者最渴望查看引起性行为的异性图像，而女性参与者则更有动力查看较少的夫妻性行为图像。这种性别差异可能反映出男人在滥交的动机和女人在长期恋爱的动机方面在男女生殖策略上的差异。