We’re surrounded by people who are good liars, with long experience of telling lies and half-truths with a straight face – including many politicians.
Good liars can often cover up the well-known signs of deceit – by preparing lies in advance, and avoiding ‘tells’ such as covering their mouths.
But psychologists and trained interrogators look for other, difficult-to-fake signs – such as ‘micro expressions’ which flash across people’s faces.
Look for rapid blinking
Mark Bouton, an FBI agent who served for 30 years, and wrote the book, ‘How to Spot Lies Like the FBI’ says that blinking can be a sign someone is stressed – and possibly lying.
Bouton says, ‘A person will ordinarily blink about five or six times a minute, or once every 10 or 12 seconds.
‘When stressed – for instance, when someone knows he’s lying – he may blink five or six times in rapid succession.’
Look for pauses when there shouldn’t be a pause
Context is everything when looking for lies – and people pausing at odd moments can be a sign that they’re not telling the truth.
Ex-CIA officers Philip Houston, Michael Floyd, and Susan Carnicero, authors of Spy the Lie, say that a pause can be the sign that betrays a liar.
They write, ‘Try this exercise on a friend: Ask her the question, “On this date seven years ago, what were you doing that day?” The person will invariably pause.
‘Now ask her, “On this date seven years ago, did you rob a gas station?” If your friend pauses before responding, you probably need to choose your friends more carefully.’
Look for people who are talking far, far too much
Liars often talk too much – in an effort to ‘flesh out’ the story, they’ll offer irrelevant details, and sometimes repeat themselves.
Dr. Lillian Glass, author of The Body Language, says, ‘When someone goes on and on and gives you too much information – information that is not requested and especially an excess of details – there is a very high probability that he or she is not telling you the truth.
‘Liars often talk a lot because they are hoping that, with all their talking and seeming openness, others will believe them.’
Look for a change after they’ve said something you know is true
Police often ask questions where they know the answers first – such as establishing a subject’s address.
Doing so helps observers see how someone looks when telling the truth, which helps to spot the moment they start to lie.
‘It’s really about how to observe very carefully,’ said Pamela Meyer, author of the book
What experts look for is change from truth-telling to deception, but not one specific change.
So they need a baseline, a sense of what people look and talk like when their guard is down and they are telling the truth.
Once a normal is established, the idea is to ask open-ended questions and look for cues,
changes in verbal and nonverbal behavior, Meyer said.
Look for people getting the details muddled
Sussex University researchers found that trying to ‘trip up’ liars with precise, detailed questions was 20 times more effective than looking for ‘liar’s tells’.
Instead of looking for physical signs, researchers tried to ‘trip up’ liars for instance, if
someone said they worked at the University of Oxford, they would ask them how they
travelled to work.
The researchers say that interviewers should use ‘open’ questions to force liars to expand
on their stories, such as ‘Can you tell me about your job’?
Small details – such as what bus number someone got – are also easily verifiable.