Martie G. Haselton

Mobile software applications (apps) have transformed how individuals oversee and maintain their own health. One way that girls can monitor their menstrual cycles is through the increasingly widespread use of mobile menstrual tracking apps. This study aimed to examine menstrual symptom tracking for adolescents in English and Chinese apps, exploring menstrual literacy, cross-cultural differences, and framing, or presentation, of symptoms. The mixed-methods content analysis involved 15 popular free menstrual tracking apps in English (n = 8) and Chinese (n = 7), sampled from December 2022 to January 2023. A quantitative analysis of qualitative data was conducted through manual coding of content and automatically analyzing sentiment, or emotional tone, using a computational approach. We found that (1) menstrual literacy on symptom management or treatment was generally insufficient, (2) there were more available emotional than physical symptoms in English than Chinese apps, and (3) symptoms were framed more negatively than positively somewhat more in Chinese than English apps. Our findings emphasize the urgency to provide better evidence-informed communication about symptoms, either presented more positively or neutrally, in menstrual tracking apps for adolescent users. Since adolescence is a critical developmental stage that requires ample support, we recommend that digital menstrual trackers be crucially improved and future research should investigate how they can uniquely shape attitudes and experiences, and subsequent sexual and reproductive health empowerment and bodily autonomy.

A surge of recent research has documented effects of reproductive hormones on human sexual behavior. And it now appears that human females—like their mammalian counterparts—experience estrous-like changes in sexual interests and attractiveness to males during the fertile phase of the ovulatory cycle.

In contrast to our closest cousin, the chimpanzee, humans appear at first to lack cues of impending ovulation that would mark the fertile period in which a female can become pregnant. Consequently, that ovulation is “concealed” in women has long been the consensus among scientists studying human mating. A recent series of studies shows, however, that there are discernible cues of fertility in women’s social behaviors, body scents, voices, and, possibly, aspects of physical beauty. Some of these changes are subtle, but others are strikingly large (we report effect sizes ranging from small, d = 0.12 to large, d = 1.20). Moreover, emerging evidence suggests that women’s male partners may adaptively shift their behavior in response to cues of approaching ovulation. These results have far-reaching implications for understanding fluctuations in attraction, conflict, and relationship dynamics.

A commonplace observation in humans is that close genetic relatives tend to avoid one another as sexual partners. Despite the growing psychological research on how antierotic attitudes develop toward relatives, few studies have focused on actual behavior. One prediction, stemming from parental investment theory, is that women should be more vigilant of reproduction-compromising behaviors, such as inbreeding, during times of peak fertility than during times of low fertility. Indeed, females of other species avoid interactions with male kin when fertile—but the corollary behavior in humans has yet to be explored. Here we fill this gap. Using duration and frequency of cell-phone calls, an objective behavioral measure that reflects motivations to interact socially, we show that women selectively avoid interactions with their fathers during peak fertility. Avoidance specifically targeted fathers, which rules out alternative explanations. These data suggest that psychological mechanisms underlying mating psychology regulate sexual avoidance behaviors, and in women they fluctuate according to fertility status.