We mistakenly attribute fidgeting, stuttering and avoidance of eye contact as outward signals of mendacity, suggests recent research into lie detection, showing that these are some of the least accurate ways to predict whether or not someone is lying.
Professor Richard Wiseman […] says that common sense is the lie-buster’s best weapon, and affirms that it is aural rather than visual clues that are key.
Wiseman’s 1994 experiment […] had 30,000 participants watching or listening to two interviews he conducted with Robin Day. In one, Day told the truth; in the other he lied. Viewers could not spot the lie: there was a near-50/50 vote. Radio listeners, however, achieved over 70 per cent accuracy.
“Lying taxes the mind,” Wiseman explains. “It involves thinking about what is plausible. People tend to repeat phrases, give shorter answers, and hesitate more. They will try to distance themselves from the lie, so use far more impersonal language. Liars often reduce the number of times that they say words like ‘I’, ‘me’, and ‘mine’. To detect deception, look for aural signs associated with having to think hard.”
According to the Canadian Journal of Police and Security Services, another side-effect of lying that forensic interrogators will look for is the avoidance of verbal contractions – using “I am” instead of “I’m” and so on.