Ovulating women unconsciously buy sexier clothes, says new research from the University of Minnesota’s Carlson School of Management. The study finds that ovulating women unconsciously dress to impress — doing so not to impress men, but to outdo rival women during the handful of days each month when they are ovulating.

“The desire for women at peak fertility to unconsciously choose products that enhance appearance is driven by a desire to outdo attractive rival women,” says Kristina Durante, a post-doctoral fellow at the Carlson School. “If you look more desirable than your competition, you are more likely to stand out.”

This research, forthcoming in the Journal of Consumer Research, provides some of the first evidence of how, why, and when consumer behavior is influenced by hormonal factors. Durante and co-authors focused their predictions on the fact that competition for a suitable partner would be influenced by a woman’s fertility status.

“We found that, when ovulating, women chose sexier fashion products when thinking about other attractive, local but not distant women,” says Durante. “If you are in New York, a woman who lives in LA isn’t going to be seen as competition.”

Although the end result is to attract the best romantic partner available, Durante’s research found that ovulating women’s choice of dress is motivated by the other women in their environment. “In order to entice a desirable mate, a woman needs to assess the attractiveness of other women in her local environment to determine how eye-catching she needs to be to snare a good man,” Durante says.

I guess that explains why so many PUAs have had experiences of picking up hot chicks, only to have them unexpectedly “pull away” at the last minute.  In case you haven’t been there, here’s the scenerio:

You go out to a bar or club, find a super-hot girl, do your work, get her attracted to you, start making out and stuff – its on.  You know it.  She knows it.  And yet, at the last minute, she puts the breaks on things.

Some guys might wonder what they did wrong, when in fact – they did NOTHING wrong.  That pesky Aunt Flo was around and reared her ugly head.  So why was a girl on her period out and about?  According to this study, not to hook up with you, but to show up other girls!  lol.  I guess that’s just more proof that women are koo-koo!