An introduction tells you that you were chosen. Two dating studies show why that gets a yes.

When a friend or a matchmaker sets you up, the first thing you learn about the other person is that someone picked them for you, and picked you for them. A like on a swiping app tells you much less. The person who sent it may have liked dozens of other profiles in the same sitting.

That difference sounds like a feeling. Two studies suggest it works more like information, and that people respond to it. We wrote about the matchmaking revival in July. These studies get at why the introduction works.

People who wanted everyone were wanted less

In 2007, Paul Eastwick, Eli Finkel, Daniel Mochon, and Dan Ariely published Selective versus unselective romantic desire in Psychological Science. They ran seven speed-dating sessions for 156 undergraduates, average age about 20. Each person had four-minute dates with nine to 13 people of the opposite sex and rated every date right afterward: how much they liked the person, how attracted they felt, and how likely they were to say yes.

The ratings showed two kinds of desire. When someone wanted one particular person more than they wanted the others, that person tended to want them back and to report more chemistry. When someone wanted nearly everyone they met, the people they met tended not to want them.

That second pattern held for men and for women. It also held after the researchers accounted for how attractive outside raters judged each person, so it did not come down to looks. The authors found a hint of the reason. The dates of the people who wanted everyone guessed those people would say yes to a larger share of the room, and that guess went with lower desire. A separate study of older adults at commercial speed-dating events pointed the same way.

A rose made a yes more likely

The second study moved the question online, inside a real dating company. Soohyung Lee and Muriel Niederle published Propose with a rose? Signaling in internet dating markets in Experimental Economics in 2015.

In the summer of 2008, a major South Korean dating company ran two special events for college-educated, never-married singles, with men 26 to 38 and women 22 to 34. For five days, each person could browse profiles and ask up to 10 people of the opposite sex for a date. Everyone got two virtual roses to attach to requests, and a randomly chosen fifth of the participants got eight. For the next four days, people decided which requests to accept.

Compared with similar requests, a request with a rose attached was more likely to be accepted. The authors checked whether roses simply caught the eye, or went along with senders who were better catches in ways the profiles did not show, and neither explained it. The rose seemed to work as a message: you are one of the few I picked.

Roses did the most work when the sender ranked higher than the recipient on the company's own desirability measure. They also seemed to add dates rather than take them from requests without a rose, and people who were randomly given eight roses started more dates than people given two.

Plenty of people left that advantage unused. Many of the men and most of the women sent requests without a rose while they still had one left. A sizable share of roses went to the most sought-after people, and in that group a rose did not make acceptance more likely.

What a swipe has trouble carrying

Put the two studies side by side, and an introduction starts to look like a way of delivering chosen interest. The friend who sets you up made a choice on your behalf, and so did the person who agreed to meet you. Nobody receiving that introduction has to wonder whether they were one of 200.

A like on a swiping app is free and often unlimited, so it has a hard time saying the same thing. Long swiping sessions make it harder still. Researchers have found that the longer people go through profiles, the more their default answer becomes no, which we covered in why a feed of strangers makes you feel like inventory.

Both studies have clear edges. Eastwick's team measured attraction among young undergraduates on four-minute, face-to-face, opposite-sex speed dates. Lee and Niederle studied two events at one Korean company in 2008, among college-educated singles in their 20s and 30s. Neither study tested a like button on a swiping app, so applying their results to the apps is our inference.

Sending interest that reads as chosen

In Eastwick's data, desire that singled one person out was returned, and desire spread across the room was not. On an app, the closest version is liking the profiles you would actually be glad to hear from, and saving your attention for those few rather than for the whole stack.

If an app gives you a limited way to show special interest, use it. In the Korean events, many people held roses back, and a rose kept in reserve did nothing for anyone.

Then aim it where it can land. The most sought-after people in the study gave a rose no extra weight, which fits what researchers found about where first messages pile up on a big dating site.

Where Bloom fits

If you want an app that isn't built around swiping, look at how many likes it gives you to send. On Bloom's free plan you get five a day, which is a reason to save them for the profiles you would be glad to hear from. Seeing who liked you is free too, so interest someone chose to send you is never hidden behind a paywall.