When it comes to the romantic field, women's ''playful'' signals can actually be misleading, warns a new study.
The research found that men and women were equally good at gauging men's interest - and equally bad at judging women's interest.
The Indiana University study, which involved speed dating, expected ladies to have a leg up in judging romantic interest, because theoretically they have more to lose from a bad relationship, but no such edge was found.
"The hardest-to-read women were being misperceived at a much higher rate than the hardest-to-read men. Those women were being flirtatious, but it turned out they weren't interested at all," said lead author Skyler Place, a doctoral student in IU's Department of Psychological and Brain Sciences working with cognitive science Professor Peter Todd.
"Nobody could really read what these deceptive females were doing, including other women," the researcher revealed.
The study has been published in the January issue of the journal Psychological Science.
The research focused on the ability of observers to judge romantic interest between others because this ability has evolutionary benefits when it comes to finding a mate.
Decisions that other people around us make, said Place, can influence or inform our own choices.
"So, if you walk into a room and there's 20 people you've never met before, being able to know which individuals might be available and which are clearly smitten by others can make you more efficient in finding your own romantic interest to pursue," he said.
To reach the conclusion, 28 women and 26 men of college age watched video clips of couples interacting on speed dates. Each participant observed 24 videos, all with different men and women, and after each rated whether the man seemed interested in the woman and the woman in the man.
The speed dating sessions were all conducted in Germany while the observer ratings were all made by students in Indiana. Despite the language difference, observers were still able to judge men's romantic interest accurately using body language, tone of voice, eye contact, how often each dater spoke and other non-verbal cues.
"How people talk might convey more than what they say," Place said.
Observers did not have to see much of this non-verbal behavior. They were just as good at predicting the speed-dating couple's interest if they saw only 10 seconds of the date as they were if they saw 30 seconds.
The researchers say this showed that observers, even with limited information, could make quick, accurate inferences using "thin slices" of behavior.
There was, however, great variability in how well observers could predict the interest of any particular speed-dater, ranging from 90 percent accuracy down to 10 percent.
In five of the videos, 80 percent of the observers thought the women shown were interested when in fact they were not - they were acting friendly even though they had no interest in the men.