Guys: If you want to look more attractive to women, ditch the razor. A survey of more than 8,500 women shows that clean-shaven men don't cut it, and men sporting 10 days of beard growth are the most attractive.

The results of the study, which were published in the Journal of Evolutionary Biology, show that men with that much growth were the most desirable, followed by men with full beards, men sporting stubble, and in last place, men who had no facial hair.

It seems that it all comes down to hard-wired evolution. "Beards may be more attractive to women when considering long-term than short-term relationships," the study out of the University of Queensland said, "as they indicate a male’s ability to successfully compete socially with other males for resources."

Facial hair is associated with masculine social dominance, and age, the researchers said.