Available online 20 August 2022

Based on the idea that women are especially attracted to ancestral markers of male genetic quality when conceptive in their cycle, scholars have conjectured that increases in women's extra-pair sexual interests during the conceptive phase of the cycle are moderated by their primary partners' sexual attractiveness. Multiple studies have examined this prediction, with largely supportive but mixed results. The current study is the first to examine whether hormonal influences—thought to mediate cycle shifts—on women's extra-pair sexual interests are moderated by partner attractiveness. 213 naturally cycling, romantically involved women (181 attending multiple sessions) participated in up to four sessions over about a month. Estrogen and progesterone levels were measured multiple times across women's cycles. Male partner attractiveness moderated associations between progesterone levels (though not estrogen levels) and women's extra-pair sexual interests. A negative association between progesterone levels and extra-pair sexual interests, a composite measure, was observed for women with relatively unattractive partners. For women with relatively attractive partners, no clear association emerged. The interaction between progesterone and partner attractiveness was robust for women's interest in extra-pair sex, a component preregistered as exploratory. The interaction effect was also significant for the absolute intensity of women's extra-pair attraction (a component item referenced in the preregistration) but was non-significant for the frequency of women's extra-pair attraction relative to typical days (a composite component specified in the preregistration). These findings inform theoretical understandings of women's sexuality.

Ovulatory cycle

Estradiol

Progesterone

Sexual desire

Attraction

Romantic relationships

log-transformed estrogen

log-transformed progesterone

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