The popular HBO series Sex and the City is coming to the big screen. The series followed relationship columnist and anthropologist, Carrie Bradshaw, as she and her three gal pals indulged in designer shoes and casual sex. As a researcher, Bradshaw somehow missed some important research findings on the subject—and that’s a pity!

For ten years, Dr. Nancy Moore Clatworthy, a sociologist from Ohio State, has been researching couples who have lived together. Clatworthy’s survey asked questions about “finances, household matters, recreation, demonstration of affection, and friends.” In every area, the couples who had lived together before marriage disagreed more often than couples who had not.

Clatworthy also observes, “The finding that surprised me most concerned sex. Couples who have lived together before marriage disagreed about [sex] most often.”

Dr. E. Mansell Pattison, chairman of the Department of Psychology at the Medical College of Georgia, believes the lack of commitment is the reason sexual relationships are the most common break up factor. In marriage, couple have time to work through sexual problems (and sex is never problem free!). But, in a live-in situation, the partners can simply go looking for other willing partners.

Sex and commitment can’t be separated. The research shows that total intimacy without total commitment leads to concerns of breaking up, often “extreme unhappiness,” and more disagreement—especially about sex. As a result, Dr. Paul Pearsall claims “Super sex requires super love, a love that is possible only in a relationship that lasts. . . .”

According to Leo (“Gimme me a hug!”) Buscaglia, living together is “pseudo-intimacy, a caricature of an intimate relationship.” And, again, researchers agree. While there may be good intercourse, there is little intimacy. It’s impossible because both partners know very well that they’re on trial.

(Click here for more of the studies.)

More recent studies on “hooking up,” or sex without any commitments, reveal the same findings:

Adolescent gynecologist, Melisa Holmes, writes in Girlology: Hangups, Hook-Ups and Holding Out, “They don’t learn to build that emotional intimacy before they get physically intimate. In the long term, that develops bad relationship habits. They may grow up not knowing how to connect with a partner on an intimate level.” The new research seems to verify earlier studies on sex that commitment is an essential element in truly satisfying intercourse.

(Click here for more of the studies.)

So, please Ms. Bradshaw, read the research before you write your next column.