From cradle to grave, we lie. Barefaced or shifty, the lie is the soft-soap on the slipway of life that makes normal social relations possible. But why, after millions of years of evolution, are we so truly terrible at detecting it?
President Clinton has admitted that he told less than the truth about his relationship with Monica Lewinsky, though the L word has yet to pass his lips. This admission apparently came as something of a surprise to his wife Hillary, who must know him better than most. But is her surprise genuine, or just another lie? Like a hall of mirrors, lies multiply into infinity. History is just a collection of the most persuasive ones.
Psychologists who have studied lying can shed a little light on the Bill and Hillary mystery. Dr Richard Wiseman of the University of Hertfordshire says that, paradoxically, strangers are better at detecting lies than those in intimate relationships.
He says: “When people are close to one another, there is truth bias. We assume that our nearest and dearest are telling the truth. And politicians are also extremely skilled at lying. They belong to a class of people called &ksquo;high self-monitors‘, which means that they are always conscious of the impression they are making.
“They are also good at lying, because they convince themselves they are telling the truth. If they have no feelings of lying, it makes it easier to carry it off.” So maybe Bill really believed that what Monica did to him in the corridor next to the Oval Office did not amount to a sexual relationship.
Evolution teaches that nothing exists without a reason, so clearly lying and our poor ability to detect it offer a survival advantage to the liar and perhaps also to the lied-to. The human visual system is staggeringly good at recognising faces, distinguishing one from another effortlessly and even seeing a face in a few blurred shadows on the surface of Mars. Yet this ability to recognise faces is not matched by the ability to read them.
Indeed, most of the visual cues we look for to detect lies are useless. Dr Aldert Vrij, a psychologist at Portsmouth University, says that we expect people to avert their eyes and fidget when they are lying, but they do not. In fact, he says, practised liars often appear unnaturally calm, making fewer gestures and giving a rigid impression.
Dr Wiseman says liars make more eye contact, not less. But there are some subtle movements, such as frequently moving the hand to the mouth, which are commoner when lying. There can be some shifting around, too, though verbal clues are more useful than visual ones.
In experiments he has done, volunteers are asked to describe two films, either truthfully reporting their views or misrepresenting them. He has found a range of verbal changes. “Liars tend to use a shorter sentence length and provide less detail,” he says. “There is a longer delay before answering, and liars tend to speak at a faster rate and at a higher pitch.”
Dr Vrij has detected a tendency towards longer pauses between words, though no overall reduction in speed of speech. “Sometimes liars stutter, when the lie is complicated or the person is surprised by a question,” he says. “If the lie is well rehearsed, there is no stutter.”
These clues are so subtle as to be almost undetectable in ordinary conversation. Dr Vrij has studied one police videotape of the questioning of a suspect who eventually confessed to murder. “He denied ever having met the victim, but confessed after a hair from the victim was found in his car,” he says. When he was lying, this murderer showed the same sort of changes of behaviour as were seen in student volunteers, but they were hard to detect. In 30 hours of videotape, Dr Vrij found only four minutes which could be usefully analysed.
Dr Wiseman has looked at videotapes of tearful appeals made on television by parents for the return of children whom, it later transpires, they have murdered. “We have looked at five or six, and we can certainly see the verbal cues that indicate lying,” he says. “But that is when we look back and know the truth.”
Tracie Andrews, who made a tearful appeal for witnesses to the alleged road rage killing of her boyfriend, refused to meet the gaze of journalists and repeatedly put her hand to her face. She was later convicted of his murder.
Dr Wiseman's experiments show that it is easier to detect lies if we first have a baseline - a video of a person telling the truth - by which to judge deviations. The implication of this is that police interrogations should start by asking questions which can be answered truthfully, as this gives a better chance of detecting later lies.
“But it is very difficult to conduct an interview and to look for these subtle effects at the same time,” he admits. “It can help to have another person to the side, just watching for the clues.”
Some psychologists believe that the face can be read, if we could but develop the knack. Dr Paul Ekman, a psychologist from the University of California in San Francisco, has spent decades trying to understand it. His facial action coding system, or Facs, distinguishes 7,000 different expressions, including 19 different smiles. He says that certain facial muscles are “reliable” - that is, hard to fake. A true smile, for example, activates the orbicularis oculi, the muscles around the eye, so that the smile reaches the eyes and does not linger only around the mouth. Gladness, disgust, sadness and anger all have reliable muscles, in Dr Ekman's view. A minority - about 10 per cent of us - have learnt to fake even these true windows into the soul, however. The actor Woody Allen uses the sadness reliable muscle, which raises and lowers his brows as he talks. And often the reliable signals are so fleeting that we hardly detect them.
Dr Ekman believes, however, that we could be trained to do so, and from time to time has come across people who are brilliant lie-detectors. Nothing fools them: not the sincere look, the eye-to-eye gaze, the baby face, or the handsome looks, all of which have been shown to make lying easier - tactics which proved so useful for John Lindsay, the bogus pilot in Coronation Street.
But the rest of us bumble along, by turns fooling and being fooled. The truth is that the little lie is so vital to the functioning of normal social relationships that evolution has ensured we cannot detect it - and thus can easily fall victim to the Great Big Lie. Those who refuse to dissemble when given a ghastly tie for Christmas are considered social misfits. Small wonder that our politicians, and our partners, can tell us whoppers from time to time and get away with it.