Our happy hour fact to amaze your drinking buddies with.

In their efforts to impress attractive females, males take unnecessarily dangerous physical risks.

Australian researchers had men observe a group of male skateboarders performing tricks in a park. Attractive women were next up to watch the extreme athletes. The skateboarders -- who didn't know any of the observers -- performed more aggressive maneuvers, and subsequently suffered more injuries, when the women were watching.

Psychology professor Bill von Hippel, who led the study, suggests "that displays of physical risk-taking might best be understood as hormonally fueled advertisements of health and vigor aimed at potential mates, and signals of strength, fitness and daring intended to intimidate potential rivals."

So if we really want to keep our parks and playgrounds safe, a ban on attractive females may be in order.