Researchers found that female night owls tend to have as much cortisol as men, which results in higher levels of energy and arousability i.e. they're total players i.e. the later you go to bed, the higher your chances of getting laid are!
Basically, if you're still awake when it's late, the chance that you'll meet someone new and hook up with them increases. Which is why you're never going to get married and die alone. In fact, the survey also shows that ladies who stay up late have even more sex partners than dudes who do the same!
348 men and 158 women were surveyed to arrive at these (obvious) results.