9. They have non-congruent gestures

If the person you’re talking with says “yes” but shakes their head as in “no,” you should doubt their credibility. Dr. Ellen Hendriksen, a clinical psychologist and anxiety specialist at Boston University, points out that non-congruent gestures are body movements that don’t match the verbal message a person sends. When this happens, the gestures are usually the truth-tellers.

So, for instance, if someone says, “Of course I’ll want to hang up with you guys again sometimes” and gives a small head shake, the chances are they don’t tell the truth.

What’s worth mentioning is that gestures tend to come a beat before the words, so if you have a hunch that somebody may be lying, look closely at their body movements.