Born Liars by Ian Leslie

to the point where they simply can’t manage to perform the mental juggling act.
    One of the interviewing techniques he recommends is to ask the suspect to tell their story backwards. By putting this extra mental pressure on suspects, those already struggling with the effort to tell a consistent lie will make mistakes that give them away. In 2007, Vrij and his colleagues published the results of a study that tested the police’s conventional techniques against their own. The research involved more than two hundred and fifty student interviewees and two hundred and ninety police officers. The interviewees either lied or told the truth about staged events. Police officers were then asked to spot the liars using the traditional methods. Those who focused on visual cues proved significantly worse at identifying liars than those looking for speech-related cues. The liars seemed less nervous and more helpful than those telling the truth. As Vrij predicted, the most reliable technique turned out to be the backwards-story test.
    Another technique designed by Vrij is the sketch test: asking people to draw a scene they claim to have witnessed. While it’s non-verbal, this technique also puts pressure on the cognitive facilities of the liar. In Vrij’s study, thirty-one participants – all of them members of the police or armed forces – were sent on a mock mission to pick up a laptop from a ‘secret agent’. Afterwards they were asked to make a detailed drawing of the location at which they’d received the laptop. Half the participants were instructed to tell the truth, the other half to lie. Vrij hypothesised that the liars, in order to make their lie convincing, would sketch a location they’d actually been to in the past, furnishing it with the kind of detail often thought to be the hallmark of a good lie. He also predicted that in doing so they’d forget a key part of the scene: the agent. The truth-tellers would be much more likely to draw the man with the laptop, as he was such a central part of the scene they had in their minds. So it proved. On the basis of this factor alone it was possible to detect who was lying nearly ninety per cent of the time.
    Although Ekman and Vrij place different emphases on what to look for, both agree on the importance of taking a holistic approach. When assessing truthfulness, a person’s voice, hand movements, posture and speech patterns should all be taken into account, and it’s vitally important to put all of this in context: do these behaviours contrast in revealing ways with how the person usually acts, and how do they square with everything else that’s known about the situation? Such judgements require many fine and fallible calculations; there is no single, all-purpose tell we can use as a short-cut. Pinocchio’s nose remains a fairy tale.
The Demeanour Assumption: Why We’re Worse Lie Detectors – and Better Liars – Than We Think
    In 2008 a group of Norwegian researchers ran an experiment to better understand how police investigators come to a judgement about the credibility of rape claims. Sixty-nine investigators were played video-recorded versions of a rape victim’s statement, with the role of victim played by a professional actress. The wording of the statement in each version was exactly the same, but the actress delivered it with varying degrees of emotion. The investigators, who prided themselves on their objectivity, turned out to be heavily influenced in their judgements by assumptions about the victim’s demeanour: she was judged most credible when crying or showing despair. In reality, rape victims react in the immediate aftermath of the event in a variety of different ways: some are visibly upset; others are subdued and undemonstrative. It turns out there is no universally ‘appropriate’ reaction to being raped. The detectives were relying on their instincts, and their instincts turned