How Soon is Too Soon to Have Sex?

"Benefits" used to mean life insurance and 401Ks. Now it means sex.

And, yes, Friends With Benefits is so much more fun than actuaries. But here's the question: If he's a friend, and you're, the benefit-or visa versa, or either way-will it go anywhere? I guess what I mean is, if you like him, will you ruin things by being just a benefit rather than the investment? When Elaine tried it back in the Seinfeld days with Jerry, the whole thing was a big nada, nada, nada.

Anthony Paik, PhD, a sociologist at the University of Iowa, set out to answer that question in his new study. Using 1995 data on 783 adults ages 18 to 60, Paik found that one out of five had gotten together with their most recent partner via friends-with-benefits or hook-up sex. He also found that these weren't particularly faithful couplings. "For women, if you start with casual sex, there's a 44 percent higher chance you'll end up in a non-exclusive relationship in comparison to those who start out in a serious relationship," says Paik. By that he means that you'll have multiple lovers; your partner is even more likely (48 percent) to cat around. Jumping into bed within the first week of meeting a guy similarly predicted a non-monogamous future.

Mind you, this is data from 1995. Today, supposedly, FWBs and hookups are even more rampant. And if drive-through sex is not the best route to the altar, as Paik's study suggests, you can just see the writing on the spreadsheet.... husbands going the way of pay phones, Father Knows Best returns as The Orgy Bunch, the whole, sad, "demise of dating," as one New York Times op-ed put it...

"I don't agree."

Hello? That's Helen Fisher, PhD, on the line. One of the best-known love scientists around (and a biological anthropologist at Rutgers), she's written five books on the subject, the last of which is called Why Him? Why Her?

So why, then, doesn't she agree?

THE WHOLE HOOKUP HYSTERIA: It's ridiculous, Fisher sighs. First of all, people have been hooking up for millions of years as a way of starting long-term relationships. "I'm doing a research project myself now with a graduate student at SUNY, Binghamton," she says, "and he has asked 551 college students why they initiated a hookup. Half of the women and 52 percent of the men said they went into it hoping to trigger a longer relationship. And one third of them succeeded."

THE ONE NIGHT STAND: Fisher explains that any kind of sexual stimulation drives up dopamine in the brain. And dopamine is associated with feelings of romantic love. On top of that, orgasm releases hormones that cause attachment. And then there's the learning curve, or curves as the case may be: "You learn a HUGE amount about somebody when you to sleep with him-just a kiss activates 5 of the 12 cranial nerves," she says referring to the senses. "You see his body, feel his rhythms, discover whether he cares enough for you to listen to your needs."

AN IMPORTANT ASIDE: Condoms, ladies.

BACK TO COURTSHIP: "Basically," Fisher says, "there are two ways to get the boy. Either you bed him right away and try to jump-start these brain systems for romantic love and attachment. Or you spend you spend a lot of time getting to know him and hope you can trigger those systems in other ways; then sleep with him. Each one works."

BOTTOM LINE: As a scientist and girlfriend, what does she suggest? "I've tried both," she tells me, laughing, pointing out that in a FWB situation one partner is probably wishing it will turn into something. "You really have to go with your gut. But personally, I think it's wise to wait a few dates. Get to know him a little. Make sure he won't just dump you. And make sure you actually like him. Something happens in the brain when you sleep with someone. Having sex is playing with fire. You could fall in love."

What do you think? Wait or jump in?

For more on "should you" or "shouldn't you"?...

Three questions to ask on a first date
10 reasons to say no to FWB
Love at first sight

[Photo Credit: Getty Images]