Using genetic information to match singles with potential partners

By Ellen McCarthy
Washington Post Staff Writer
Sunday, January 24, 2010

Eric Holzle would like to help you find love. And to do so, he just needs a little bit of your DNA.

Holzle is the founder of, one of a new generation of online dating companies that use genetic information to match singles with potential partners.

Holzle, a mechanical engineer by trade, came up with the idea several years ago after reading about a Swiss study that's become known as the "sweaty T-shirt experiment." Scientists asked a group of men to wear the same T-shirt to bed two nights in a row. The T-shirts were then given to a group of women who were asked to rate the attractiveness of the scent left on each shirt. Women rated the shirts worn by men whose immune system genes were very different from their own as the most appealing, a result that's been replicated in several subsequent studies.

"When I saw that experiment I thought it was a great idea on which to base a dating service," Holzle says. So now, for $2,000, those who want science to have a hand in their love lives can purchase a lifetime subscription to ScientificMatch, which promises to introduce them to genetically compatible singles., a Swiss company that works with other online dating services around the world, operates on a similar premise.

ScientificMatch subscribers are asked to send in a DNA sample --"just a cotton swab you rub on the inside of your mouth for a few seconds," Holzle explains -- which is then analyzed and entered into a database. Users are still asked to create profiles that include photos and information about their interests and personalities. Genetic information isn't shared with any of the users, but only profiles of people with compatible -- meaning very different -- immune system genes will pop up as matches.

It is, Holzle knows, a prospect many see as jarring, if not creepy. But he argues it's not much different than taking an online personality test and letting a computer algorithm make your matches.

"There are many pieces to the puzzle of love and we are very far from solving that puzzle. We can't predict who is going to fall in love with whom -- we're nowhere close to that. But we know that there are certain pieces," he says, mentioning that people tend to end up with partners from similar socioeconomic backgrounds and who have similar levels of intelligence. "And another critical piece to the puzzle of love is what we're doing -- physical chemistry, sexual chemistry."

Holzle points to other studies showing that people with genetically compatible immune systems have healthier children and more satisfying sex lives.

R. Douglas Fields, a neurobiologist at the National Institutes of Health who has studied the effect of pheromones, says biology can play a profound, if unconscious, role in our mate selection. "But something as complicated as human relationships," he says, "is going to be controlled by more complicated processes than simply that."

ScientificMatch launched its service in December 2007 in the Boston area and is planning to expand around the country through partnerships with traditional matchmakers. Holzle won't say how many users the site has or whether the company is profitable.

And though the 45-year-old is single himself, he hasn't used ScientificMatch because he lives in the Miami area, where they've yet to roll out the service. But he did test the science by collecting DNA samples from previous girlfriends to see if he'd been attracted to women who were genetically compatible.

"And anecdotally," he says, "it's very accurate."

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