You thought you were being so obvious with your jokey comments and playful arm-punches. After all, you don’t brush lint off anyone’s jacket. You don’t gently teaseeveryone when they take an extra-large helping of mashed potatoes.

We flirt with the people we think are cute and might want to date. And yet, so often, the recipients of our overtures seem oblivious. And so, with heavy hearts, we back off, assuming the objects of our affection aren’t interested.

But wait — there could be another reason. It’s very possible that the other person simply isn’t picking up on those signals.

A recent study by researchers at the University of Kansas found that most people are terrible at flirting. We don’t know how to convey interest, and we are incredibly obtuse when it comes to reading other people’s signs — or at least the positive ones.

“If you think someone is not interested in you, you are probably right, they are not interested. But if someone is, you probably missed it,” said Jeffrey Hall, an associate professor of communication studies at KU and author of the 2013 book The Five Flirting Styles.

In the first experiment, 52 pairs of single, heterosexual college students were told they were participating in a study on first impressions. The students talked for 10 to 12 minutes and later completed questionnaires in separate rooms. Along with many other questions, students were asked if they flirted and if they thought their partner had flirted.

In 80% of the cases, participants correctly noted that their counterpart had not flirted with them. However, only 36% of men and 18% of women were aware when their partner was flirting. In one heartbreaking case, both the man and the woman in the pair flirted with each other, but didn’t think the other one was flirting back. Hall explains:

Behavior that is flirtatious is hard to see, and there are several reasons for that. People aren’t going to do it in obvious ways because they don’t want to be embarrassed, flirting looks a lot like being friendly, and we are not accustomed to having our flirting validated so we can get better at seeing it.

And if you think bringing a wingman will help your game, think again. In another study, 250 participants watched short video clips of the pairs in the first experiment, seeing each person one at a time, and were asked if they were flirting. The group was only able to successfully identify flirting 38% of the time.

The least accurate predictions came from women watching men, who were only able to pick up on the guys’ overtures 22% the time.

Hall said that it wasn’t that the men had greater intuition, but the women were more clear about their intentions.

So if you like someone, don’t assume they aren’t interested just because they didn’t pluck a stray eyelash off your cheek. And don’t rely on light arm touches and wry humor to convey your intentions. Sometimes, the only way to know another person’s feelings is to tell them yours.