Hip width and risk of birth-related trauma may play a role in a woman's decision to have sex. A recent UK study into how a woman's build influences her sexual behavior showed that women who were more inclined to have one-night stands had wider hips

Women can now blame their one-night stands on their wider hips. Or at least that is what a recent study published in the journal, Archives of Sexual Behaviour, would have us believe. 

Couple making outThe study into whether hip width or waist-to-hip ratio was a better predictor of a woman's sexual behavior was conducted among 148 women between 18 and 26 years old, recruited from around the University of Leeds and its environs. All the participants had their hip width (defined as the distance between the upper outer edges of the iliac crest bones of the pelvis), their hip circumference at the widest point and their waist circumference at its narrowest point measured. All the women also answered a questionnaire about thier sexual histories, including the age at which they lost their virginity and the number of sexual partners they have had in the past. Results from the study showed that the number of sexual partners a woman had was largely driven by one-night stand behaviour, which in turn correlated better with their hip width and not the waist-to-hip ratio.

Overall, women in this study with hips wider than 36 centimeters (14.2 inches) had more sexual partners and more one-night stands than women with hips under 31 centimeters (12.2 inches) wide. More specifically, the women for whom one-night stands accounted for three out of every four of their sexual relationships had hips at least two centimeters (0.8 inches) wider than their counterparts in whose lives such fleeting relationships were not as prevalent.

Lead author Colin A. Hendrie of the University of Leeds and her co-authors Victoria J. Simpson and Gayle Brewer, feel that there is an evolutionary reason for their findings. Women with wider hips are more likely to engage in sex as they have an easier and less traumatic child-birth process as compared to smaller-hipped women. According to Hendrie, "Women's hip width has a direct impact on their risk of potentially fatal childbirth-related injury. It seems that when women have control over their own sexual activity this risk is reflected in their behavior. Women's sexual activity is therefore at least in part influenced by hip width."

However, before women start start measuring their hip widths based on this, the lead author does sound a note of caution saying that further research is required before these conclusions can be generalised to other populations and cultures.

Source: Springer article in Archives of Sexual Behaviour (April 2014)