New dating site Findyourfacemate.com, set to launch this month, believes it knows what we really want in a partner: one who looks like us. The story behind its novel theory of attraction—and why it accounts for the initial spark but can’t promise lifelong compatibility.

1. THE EUREKA MOMENT

Founder Christina Bloom got the idea from personal experience; friends would tell her that she and her ex-husband “looked like brother and sister.” “I actually became very fixated on the thing,” she says. “Whenever I talked about it, people said I didn’t know what I was talking about. And that I was crazy. But I would see it so clearly!”

2. CUPID’S ALGORITHM

Findyourfacemate.com is powered by facial-recognition technology developed by Face.com, which zeros in on nine points on each face—the eyes, ears, nose, chin, and the corners and center of the mouth—to find similarities.

3. ANCILLARY FACTORS

Once facial matches have been found, users can select candidates who share their values and personal style, which still matter: An L.L. Bean fan “is not going to be interested in a Versace-type person,” Bloom explains.

4. RESEMBLANCES, NOT MIRROR IMAGES

The site won’t always match you with people who look like your twin. “It’s not [perfect] symmetry as much as it is shape and structure,” says Bloom.

5. WHAT THE SCIENCE SAYS

In a 1989 study published in the Journal of Social and Personal Relationships, male and female “raters” were asked to judge the faces of 60 couples (some real, some strangers included as a control) on a nine-point scale, where 1 represented no similarity and 9 indicated the hypothetical case of opposite-sex twins. The average score for non-couples was 3.52; among actual couples, the average was 4.05. Concluded the study: “The results suggest that the observation of facial resemblance among couples appears to reflect a real phenomenon.”

6. THE THEORY IN ACTION

Examples of the dating-your-face dynamic can be found in celebrity couples who share a resemblance (a few of which you’ll find in the slideshow above) and stars serially attracted to men and women who could be their siblings (think of Ryan Phillippe and doe-ish Reese Witherspoon … and Abbie Cornish … and Amanda Seyfried).

7. LIKENESS ISN’T EVERYTHING

The site only accounts for initial attraction. “We say that the chemistry and the face matching is the required first step,” Bloom explains. From then on, compatibility is up to you. Even if you’re almost identical, it doesn’t mean you’ll agree on who should take out the garbage.

Photo: Patrick McMullan

Photo: Olycom/iPhoto/Newscom

Photo: Patrick McMullan