Why You Can't Spot a Liar Just by Looking

According to deception researcher Maria Hartwig, it's a misconception that you can spot a liar by the way they act.

Despite decades of searching, researchers have found little evidence to support belief about liar's behaviors such as - averted gaze, rapid blinking, talking louder, shrugging, fidgeting, stuttering, movement of the hands, arms, or legs, exaggerated yawning, covering the mouth while speaking, whistling, excessive personal grooming .

None proved reliable indicators of a liar.

Deceivers can successfully hide nervousness. “The whole point is, liars do feel more nervous, but that’s an internal feeling as opposed to how they behave as observed by others.” says Ronald Fisher who trains FBI agents.

Even when the stakes are high, some liars can control their behavior to counter the stereotypes. 

So, behavioral analysis shouldn't be the end rule to decide whether someone is lying or not.