They found that a 5-foot-8 man was just as successful in getting dates as a 6-footer if he made more money — precisely $146,000 a year more. For a 5-foot-2 man, the number was $277,000. [For more of these trade-offs, see nytimes.com/tierneylab.]

Image Credit... John Hersey

Online dating reveals the most exquisite calibrations of the Flaw-O-Matic because the daters fill out questionnaires listing more attributes than could ever fit in a personal ad. They can spend all day finding minute faults in hundreds of potential partners. But that’s also why so many people never make a lasting match.

“When you have all these criteria to consider, and so many people to choose from, you start striving for perfection,” Dr. Ariely says. “You don’t want to settle for someone who’s not ideal in height, age, religion and 45 other dimensions.”

It’s the same problem afflicting New Yorkers: with so many prospects in the big city, they refuse to stop searching.

Customers of online dating services typically end up going out with fewer than 1 percent of the people whose profiles they study online. But something very different happens at a speed-dating event. The average participant makes a match with at least 1 in 10 of the people they meet; some studies have found the average is 2 or 3 out of 10. Women are still pickier than men, and in some speed-dating experiments they still prefer affluent, well-educated men, but the preference is less strong — and in some other studies they don’t discriminate at all by income or social status.

What happens to speed daters’ Flaw-O-Matics? The people at these events realize that there aren’t an infinite number of possibilities. If they want to get anything out of the evening, they have to settle for less than perfection. They also can’t help noticing that they have competition, and that their ideal partner just might prefer someone else.