Women choose bad boys because their hormones make them, new research suggests. When ovulating a woman's hormones influence who she sees as good potential fathers, and they specifically pick sexier men over obviously more dependable men.

"Previous research has shown in the week near ovulation women become attracted to sexy, rebellious and handsome men like George Clooney or James Bond," study researcher Kristina Durante, of The University of Texas at San Antonio, said in a statement. "But until now it was unclear why women would ever think it's wise to pursue long-term relationships with these kinds of men."

The study was published today, May 14, in the Journal of Personality and Social Psychology.

The researchers had women view online dating profiles of either a sexy man or a reliable man during periods of both high and low fertility. Participants were asked to indicate the expected paternal contribution from the men if they had a child together based on how helpful the man would be caring for the baby, shopping for food, cooking and contributing to household chores. Near ovulation women thought that the sexy man would contribute more to these domestic duties.

"Under the hormonal influence of ovulation, women delude themselves into thinking that the sexy bad boys will become devoted partners and better dads," Durante said. "When looking at the sexy cad through ovulation goggles, Mr. Wrong looked exactly like Mr. Right."

The researchers followed up that find with a second study in which women interacted directly with male actors who played the roles of sexy cad and reliable dad once during ovulation and again at low fertility. Again, ovulating women thought that the sexy cad — but not the reliable dad — would contribute more to childcare, but only as her partner (not if he shacked up with another woman).

"When asked about what kind of father the sexy bad boy would make if he were to have children with another woman, women were quick to point out the bad boy's shortcomings," said Durante. "But when it came to their own child, ovulating women believed that the charismatic and adventurous cad would be a great father to their kids."

"While this psychological distortion could be setting some women up to choose partners who are better suited to be short-term mates, missing a mating opportunity with a sexy cad might be too costly for some women to pass up," said Durante. "After all, you never know if he could be the 'one.'"