Thread: Study: Sex Hormone Driving Women's Infidelity

"Research by psychologists at the University of Texas has indicated that high levels of the hormone oestradiol are present in women prone to flirt and have extra-marital affairs.

The conclusion is that raised levels of the sex hormone may make women more likely to cheat on their husbands or partners.

Researchers Kristina Durante and Norman Li suggest that the behaviour, rather than being linked to sex for its own sake, may be driven by a woman's desire to find a mate 'better' than her current partner.

High levels of oestradiol also boost women's fertility. Some studies claim to show that over the course of our long evolution men have become adept, albeit unconsciously, at picking up on certain signals that a woman has high levels of the hormone.

Women who produce high concentrations of oestradiol are likelier to have bigger breasts, more attractive faces and lower waist-to-hip ratios than women who don't. Little wonder then that this group is able to play the field. If they feel like being unfaithful, there'll be no shortage of willing male partners and - after the affair and the divorce - second husbands.

Recording the hormone levels at different points in the menstrual cycle of fifty-two women aged 17 to 30, the researchers asked their subjects to say how sexy they felt they were in relation to other women. They were also asked to say how content they were with their partners and how likely they felt they were to have casual sex outside their relationship. They were also asked for detail of past relationships.

Meanwhile, a separate group of men and women, unaware of the aim of the research, was asked to rate photos of the women, saying how attractive each was judged to be.

The women with the highest concentrations of oestradiol were consistently rated as more attractive. They were also the women who stated they were likeliest to have an affair. And the same group of women reported the greatest number of past relationships.

The researchers concluded that oestradiol-enhanced attractiveness gives women an edge in the competition to find a good mate. Biologically speaking, they reason, men are looking for women who are sexually attractive and fertile while women seek partners who are attractive and 'good providers'.

Durante and Li argue that women evaluate the different benefits of having "a long-term mate who provides continual material resources, and more physically attractive short-term sexual partners with good genetic resources." They conclude that women with higher oestradiol levels "may have fewer reasons to be committed to any particular partner if higher quality potential mates are available."

So although the guy who gets the sex kitten may be having a good time, he may also lose her quite easily to a better-looking, richer male."