We get lied to all the time. People are dishonest with us out of politeness, to avoid punishment, to protect others, or to deliberately mislead us for personal gain.
Liars can "leak" nonverbal information in telltale "micro expressions" (those genuine emotions that flash across someone's face in less than one-fifth of a second) and "suppressed expressions," which slip out before realized and are then replaced with more acceptable reactions.
Behaviors suggesting deception
Yes, there are behaviors that suggest deception. Some examples are:
- Incongruence between what's being said and the speaker's body language (like saying "no" while nodding "yes").
- An increased blink rate - especially over 50 blinks per minute - or eyelid flutter.
- Gazing downward after asserting innocence.
- Shorter, less descriptive statements.
- Incomplete gestures, like a shrug that uses only one shoulder.
- A decrease in hand gestures, especially those used to illustrate speech - like drawing pictures in the air to help explain what is meant.
- Fidgeting feet that shuffle, wind around each other, stretch and curl or kick out.
- Dilated pupils.
- Face touching - especially around the mouth and nose.
- Discrepancies in timing: When the lie is well rehearsed, deceivers start their answers more quickly than truth-tellers. If taken by surprise, however, the liar takes longer to respond.
It's also true you are already subconsciously picking up on signals of deception. Your ability to do that is one of your basic survival instincts.
And yet, it's not so simple...
But, as innate as this ability may be, and as compelling as the scientific research is, it's not all that easy to catch a liar. Here's why . . .
1) There is no absolute signal for deception. Most cues, including blink rates, vocal tone, pupil dilation, etc., are signs of heightened anxiety and stress. But there is no way of telling if the observed stress is caused by lying or by something else. Likewise, incongruence, where gestures contradict words, may be a sign of deceit or simply an indication of some inner conflict between what the person is thinking and saying.
2) Signs of deceit may differ from individual to individual. Take eye contact, for example: Some liars shift their gaze and won't meet your eyes, while others give too much eye contact. one person may raise her vocal pitch when she lies while another speaks in a flat, unemotional tone.
3) Nonverbal cues need to be evaluated in what is called a "gesture cluster" - movements, postures and actions that (taken together) reinforce a common point. A single gesture can have several meanings or mean nothing at all. So when you are trying to catch a liar, you can never do it from a signal deceit behavior.
4) It's tough to spot deception unless you know a person's baseline behavior under relaxed or generally stress-free conditions. The more you understand which gestures or postures are part of someone's unique repertoire, the more you can spot significant deviation from these patterns. This is why police interrogators begin with a series of broad, non-threatening questions to help establish that baseline.
5) All nonverbal communication is influenced by cultural heritage, and the higher the stress level, the more likely it is that culture-specific gestures will show up. It is extremely difficult to judge nonverbal deception cues in people from another culture.
6) No one, not even with the aid of functional MRIs to track brain activity, can identify liars who believe the lies they are telling.