Business magazine Forbes.com ran a good article on lie detection in summer 2010: Ten Ways To Tell If Someone’s Lying To You. (For the article and slideshow click here.)
Drawing on the experience of police interrogators and psychologists, the article makes some interesting points. For example, although people often say lies are revealed by nervous behaviour like fidgeting, police interrogators know very well that truthful people may exhibit nervous behaviour when questioned and practised liars may avoid it.
Instead it seems it’s better to concentrate on the content of what you’re being told. Is there convincing detail? Or is the detail lacking? If you ask to hear the same account or story again, is it consistent?
Pushing for more detail is a tried and tested interrogation technique. It’s easy for someone to say they were working late but if they’re asked what work they were doing, if anyone else was around, what time they left, whether they had anything to eat or drink and if so what, the story may start to falter.
Another thing to look out for is aggression. Although police interrogators and psychologists say that although experienced liars tend to stay pleasant, less experienced liars are often aggressive when answering questions. People with something to hide tend to feel threatened by questioning, for obvious reasons, and that can manifest itself in bad temper or unpleasant behaviour.
Tone of voice is important too. If the tone rises and becomes higher at certain points in an account it may be worth pressing for further detail around what’s being said.
Listening for hesitation is important in lie detection too. If someone isn’t telling you the truth when you ask a question they’ll quite often pause for a second or two in order to come up with what they think is a convincing lie or to evade the question altogether.
Of course everyone accepts or ignores small lies every day. It’s just not important, usually, to know if your colleague really likes your new haircut. But if you’re negotiating a contract, for example, and the guy across the table is lying through his teeth telling you he’s already almost able to supply something in the small print and it’ll definitely be ready by the time the contract’s in force, it’s useful to know it’s not true. Pushing for detail is a good way to help establish the truth.
Equally, a woman may not care if her husband went to the pub when he said he was working late but she’d almost certainly want to know if he went to a hotel with a call girl. Or would she? Psychologists say that quite often liars get away with lying simply because the people they’re lying to don’t want to hear the truth.
One woman who did want to know the truth and instinctively used a simple question to find it out is Maria, a 39-year-old Irish accountant and divorced mother of two. “I suspected my husband Kevin was seeing another woman” she says “but he denied it. We had a sort of a row about it one evening and he again denied seeing this colleague of his. When I first knew him he would occasionally say ‘I swear on my mother’s life’ to underline that something was completely true. He hadn’t said it for a long time but that evening during the row it just popped into my head. As he said again that he wasn’t sleeping with this woman I said very quickly ‘Will you swear that on your mother’s life?’ He looked completely taken aback and hesitated. It was the absolute turning point of our marriage. With that pause I knew he was having an affair – and he knew that I knew. I’m sure he still thinks that that question was the reason our marriage ended in divorce. It wasn’t of course. It was his affair and his lying.”