It is hard for people to detect flirtatious behavior, according to a new study by the University of Kansas.

"If you think someone is not interested in you, you are probably right, they are not interested," Professor Jeffrey Hall said in a statement. "But if someone is, you probably missed it."

Researchers said that just 36 percent of men knew when a woman was flirting with them. While 18 percent of women correctly identified when men were making advances toward them.

"Behavior that is flirtatious is hard to see, and there are several reasons for that," Hall said. "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."

For the study, researchers asked 52 single heterosexual college students to converse with each other for 10 minutes. They then completed a questionnaire that asked them if they had flirted with their partner and whether they thought that their partner flirted with them.

The researchers said that more than 80 percent of the participants guessed it correctly when their partners were not flirting with them.

In the second part of the study, more than 250 participants were asked to watch the couples' interactions and determine whether they were flirting with each other or not.

Hall found that flirtation was indeed difficult to spot. Only 38 percent of the participants correctly guessed when flirting had occurred. On the other hand, two-thirds or 66 percent precisely detected when couples were not flirting with each other.

Hall said that it's tricky to identify a liar because most people are telling the truth most of the time. The same holds true for flirting.

"Most people on most days are not flirting with everyone they come in contact with," Hall said. "But some people are occasionally flirting and maybe a few people are flirting a lot."

The study titled "Accurately Detecting Flirting: Error Management Theory, the Traditional Sex Script, and Flirting Base Rate" is published in Communication Research.