But since so many gestures have multiple meanings, even the most highly trained experts only have around a 60 percent success rate of figuring out what physical responses mean.
So what are your chances of reading body language on an average date, especially once you factor in low lighting, two drinks, and maybe some Botox?
A 2016 study tested this phenomenon in two settings: speed dating and online dating.
In the speed-dating experiment, experimenters filmed 144 speed dates, and reviewed them looking specifically at whether people sat still or waved their hands and arms a lot.
"For every single unit increase of expansiveness on the scale, that person was 76 percent more likely to get a 'yes' response from their speed-dating partner," Vacharkulksemsuk said.
In another part of the study, the researchers analyzed thousands of reactions to photos of the opposite sex on a mobile dating app.
And remember your own body language: The time spent changing outfits or planning what you are going to say next would be much better spent making your date comfortable enough to establish a "baseline."To be a human lie detector, you have to establish a baseline or find out what is "normal" behavior for the person in question—so that you can tell when something is off.
Getting to the baseline can take as little as three minutes.
So, how do we put our best foot forward without talking too much or not talking at all?An open posture is "expansive," featuring widespread limbs and a stretched torso that "enlarge" a person's space, Vacharkulksemsuk said.A person with a closed posture, by contrast, keeps limbs close to the body and minimizes himself or herself."Body language isn't as much about the reality of what you're doing, it's about the perceived value of your actions," says Chris Ulrich, senior instructor at the Body Language Institute.Basically, it doesn't matter how into someone you are if you're giving off the wrong signals.