How to become a human lie detector

25 January 2016 -


Lies in the business world can have serious consequences for organisations and individuals. 

Here’s some top tips for spotting the serious lies that could be damaging your business

Guest blogger Adrian Furnham



While we all tell face-saving and impression management “porkie pies” some people tell serious, illegal and very damaging lies that wreck businesses and lives.

Hence lie detection is serious business.

There are a lot of ‘body language experts’ – self-appointed gurus who claim to have considerable skill and accuracy in detecting lies – but the data say otherwise. Gaze avoidance, nose touching and squirming in a chair are indeed all associated with lying, but also with general anxiety about being interviewed.

Usually lying is hard work. Not the kind of ‘white-lie’ lying intended to avoid social embarrassment and injured feelings, but serious lying with serious consequences. Claiming to do things you didn’t do, or to have been somewhere than you actually were present a significant important event.

The reason lying is difficult and demanding is because you have to do several things at the same time:

  1. You have to get the story right: it must be plausible and consistent with all known (revealed and revealable) facts. This may involve serious research.
  2. You have to memorise the story well so that you are completely consistent in re-telling it many times while possibly being recorded.
  3. You have to scrutinise your interlocutors to ensure they are swallowing the bait. You need to know what to look for in others.
  4. You have to memorise the script and also perform: the emotions displayed need to match the story. This takes effort and style.
  5. In addition to remembering the script, you have also to repress or suppress memories of the actual occurrence.

So it takes a good memory, acting skills, emotional intelligence and sheer effort to tell a lie (many times) convincingly and get away with it.

That is why experts talk of ‘duping delight’; catching liars after the event when they become suddenly relieved and relaxed after their performance has ended.

Some experts in the field of lie detection published a study (Current Directions in Psychological Science, Volume 20) that utilised the idea of increased ‘cognitive load’. They recommend some pretty nifty tricks to catch liars:

Tell the Story in Reverse Order

It’s not that easy to do, but much easier if the story has not been fabricated. Sequences are not always well thought through by liars and the fumbling-bumbling can soon be spotted. Try it out and see what they mean.

Maintain Eye Contact in the Telling

Liars have to concentrate inwards. Other people are arresting and distracting. Their gaze often shifts to motionless objects as they ‘go inwards’. Maintaining eye contact is very difficult if you are trying to remember your lines. You need to look away to “look inward” to try to maintain the story.

Using Unanticipated Questions

Liars are sensitive to saying “I do not recall/remember/ know”. It sounds fishy. So they learn to give plausible answers. So ask questions they don’t expect and ask them more than once.

If they lie about a meal ask them what the other person ordered, who finished first, where their table was. Ask them about colours, smells, incidentals. Ask the same question again phrased differently. Get them to draw a room and look for details. This can seriously rattle them.

Devil’s Advocate

A lot of lies are about opinions and beliefs. Good liars are usually able to articulate a clear ideological position. So ask them to be the devil’s advocate in effect providing their true opinions about an issue. Liars are faster at this and give richer, more complex answers than those who are telling the truth.

Strategic Questioning

Most liars have to do avoidance and denial. They need a number of strategies to avoid having to admit or describe true events as well as denial strategies. Innocent people say more, fearing interviewers do not have all the facts; guilty people say less for fear of incrimination. So clever interviewers ask open and then closed questions. Innocent people are more likely to spontaneously offer facts than liars.

The use of these and other specific techniques depends on the situation, the crime and the preferences of the lie detectors.

For those who simply call for a polygraph the news is not good. It does too many false positives (claiming people are lying when they are not) and false negatives (failing to pick up those who are lying). They are also expensive and unreliable.

The trouble with lying is that to be successful you have to be skilful, determined and well prepared. It helps to have a weak conscience because you don’t want to leak too much in the setting.

That is why psychopaths lie so well because the abiding characteristic of the psychopath is lack of conscience.

And it is that small, quiet voice of the developed conscience that so often lets people down.

Adrian Furnham is a business psychologist and author of 80 books and 1,000 scientific papers. He is an adjunct professor at the Norwegian Business School. Find his website here

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