Listen up, ladies. The next time you bag a boy and are unsatisfied with his, uh, stamina, keep in mind that his quick shooting style is genetic, not psychological. According to a recent Dutch study, neuropsychiatrist Marcel Waldinger and pharmacological researcher Paddy Janssen at Utrecht University, rounded up 89 subjects who suffer from premature ejaculation, and 92 men who can last for hours and did a little brain compare and contrast. In the time-challenged group a lack of serotonin was the culprit. Serotonin---known as the brain's regulator of mood and sexual appetite---seems to ward off coming when it's more active in the nerves controlling ejaculation. So, the more serotonin the longer the sex. Upon further investigation, the researches isolated the gene 5-HTTLPR, which is responsible for the amount and activity of serotonin, and pinpointed the three variations of the gene: LL, SL, and SS. If you're one of the unlucky guys born with the LL version, than chances are you're the brunch time butt of your past sexual conquests minute man jokes. Men with the SL version are the Ron Jeremy's of the group, having the natural ability to last the longest, where the SS group is average.

Wow. And us ladies curse the powers that be for our finicky orgasms. Turns out penises aren't as simple as we once thought!