They have long been known as those with child-bearing hips.
Now a new study has revealed that women with wide hips are more likely to have one-night stands and more sexual partners in general.
This is essentially because they do indeed find childbirth less traumatic, the authors suggest.
The researchers define wide hips as those wider than 36 centimetres and small hips as those under 31 centimetres wide.
This is measured by the distance between the upper outer edges of the iliac crest bones of the pelvis - the widest part of the hip bone.
The measurement is that across, not the circumference.
The 148 women in the study - aged between 18 and 26 - also had their hip circumference at the widest point measured and their waist circumference at its narrowest point.
All the women had at least one sexual partner previously. They also completed a questionnaire about their sexual histories, including the age at which they lost their virginity, the number of sexual partners they'd had, and information about emotionally significant sexual relationships they had had.
The researchers, from the University of Leeds, found women who were more inclined to have one-night stands had wider hips.
More specifically, the women for whom one-night stands accounted for three out of every four of their sexual relationships had hips at least 2cm wider than those who had fewer one-night stands.
The researchers, led by Professor Colin Hendrie, suggest that women with wider hips have more sexual partners because the birth process is generally easier and less traumatic for them than for smaller-hipped women (below 31cm).
"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 behaviour," he said.
"Women's sexual activity is therefore at least in part influenced by hip width."
He explained the study findings relate back to how humans learned to walk upright and the subsequent development of narrower hips to make it easier to walk.
In the process, female hips have become just wide enough to allow childbirth. Infants are born at a less developed stage than most other primates because of this restriction, and therefore need much more care and investment after birth from their mothers and father, they say.
The research is published in the Archives of Sexual Behaviour.
- DAILY MAIL