A new study from the University of Leeds suggests that a woman’s hip width may be linked to her likelihood of engaging in casual sexual encounters, such as one-night stands. The research, which was published in the Archives of Sexual Behavior, found that women with wider hips reported having more one-night stands compared to their peers with narrower hips.
The researchers set out to explore a question that had not been fully answered in previous studies. Past research has long focused on the waist-to-hip ratio as a marker of attractiveness, fertility, and health. However, little attention had been paid to whether the actual width of a woman’s hips could have its own role in influencing sexual behavior.
Given that the evolution of human bodies has been shaped by the competing needs of walking upright and giving birth, the study aimed to find out if hip width itself might serve as a signal related to a woman’s reproductive experience and, in turn, her sexual decisions. The underlying idea was that wider hips may indicate a safer or less difficult childbirth, which could potentially influence a woman’s comfort with engaging in more casual sexual encounters.
To investigate this possibility, the researchers recruited 148 women between the ages of 18 and 26 from the University of Leeds and nearby areas. All of the participants had been sexually active, with each having had at least one previous sexual partner. A trained researcher took several body measurements from each participant. One of the key measurements was hip width, defined as the distance between the upper outer edges of the pelvic bones known as the iliac crests. In addition to hip width, the researcher also recorded hip circumference at the widest point and waist circumference at the narrowest point. With these two measurements, the study calculated the waist-to-hip ratio, a value that has been used in many earlier studies on physical attractiveness and reproductive health.
After the physical measurements were taken, each participant filled out a questionnaire about her sexual history. The questions asked about the age at which they lost their virginity, the total number of sexual partners they had had in their lifetime, and details about their emotionally significant relationships. In particular, the questionnaire aimed to capture the number of casual sexual encounters, or one-night stands, as opposed to relationships that involved a more committed or emotionally involved partner. The researchers also collected information that allowed them to calculate the number of sexual partners per year of sexual activity, which helped account for differences in the ages of the participants and the length of time they had been sexually active.
Once all the data had been gathered, the researchers compared the physical measurements with the information about sexual behavior. They found that the number of sexual partners reported by the women was largely driven by the number of one-night stands they had. More interestingly, this behavior was directly correlated with hip width. Women with hips wider than approximately 36 centimeters, which is about 14.2 inches, had more sexual partners and engaged in more one-night stands than women whose hips were less than about 31 centimeters, or roughly 12.2 inches, wide.
Furthermore, the analysis showed that women for whom one-night stands made up three out of every four of their sexual encounters had hips that were on average at least two centimeters wider than those of women who did not engage in casual sexual encounters as frequently.
In contrast, the waist-to-hip ratio did not show any significant connection with the measures of sexual behavior. This means that while earlier studies have highlighted the importance of waist-to-hip ratio in signaling fertility and overall health, it was the absolute measure of hip width that was related to a woman’s sexual activity in this study.
The researchers suggest that this finding may be linked to the risks associated with childbirth. According to their interpretation, women with wider hips might face a lower risk of experiencing severe complications during childbirth. This possibility is tied to the long evolutionary history of human beings: as our ancestors adapted to walking on two legs, there was a natural tendency for the hips to become narrower to aid in efficient movement.
Yet, at the same time, there remained a need for the hips to be wide enough to allow for the safe passage of an infant during birth. Women with hips that are on the wider end of the spectrum may therefore experience less physical risk during childbirth, a factor that might unconsciously influence their approach to sexual activity.
The findings of the study open up interesting questions about how physical characteristics shaped by evolution can influence modern behavior. The researchers speculate that because childbirth can be dangerous, even in modern settings, women might be naturally inclined to consider the risks associated with sex. If a woman’s body is structured in such a way that the birth process is less risky, she may be more likely to engage in casual sexual encounters without as much concern for potential future complications. While these ideas are still in the early stages of scientific investigation, the current research provides evidence that the width of a woman’s hips may be a factor in her sexual decision making.
Despite the intriguing findings, the study does have some limitations. The sample was relatively small and consisted only of young women recruited from a university and its surrounding areas. This means that the results may not apply to all age groups or to women from different cultural and socioeconomic backgrounds. The researchers also point out that the study was based on self-reported sexual histories, which can sometimes be affected by memory errors or personal biases. In addition, while the study shows a clear association between hip width and one-night stands, it does not prove that wider hips directly cause a woman to engage in more casual sexual encounters. Other factors that were not measured in this study, such as personality traits or social influences, might also play a significant role in shaping sexual behavior.
Looking ahead, the researchers suggest that future studies should include a more diverse sample of women to see if these findings hold true across different cultures and age groups. Further research could also investigate whether other aspects of physical build, as well as non-physical factors, interact to influence sexual behavior. More detailed studies might examine how psychological and social factors work together with physical traits to shape a woman’s decisions about sexual encounters.
The study, “Evidence to Suggest that Women’s Sexual Behavior is Influenced by Hip Width Rather than Waist-to-Hip Ratio,” was authored by Victoria J. Simpson, Gayle Brewer, and Colin A. Hendrie.
