It is often claimed that even the most stone-faced liar will be betrayed by an unwitting eye movement.
But new research suggests that that "lying eyes", which no fibber can avoid revealing, are actually a myth.
Verbal hesitations and excessive hand gestures may prove a better guide to whether a person is telling untruths, according to research conducted by Professor Richard Wiseman.
Many psychologists believe that when a person looks up to their right they are likely to be telling a lie. Glancing up to the left, on the other hand, is said to indicate honesty.
But the experts are wrong, according to Professor Wiseman and his team of researchers, who tested whether eyes really can reveal lies.
The claimed link between lying and eye movements is a key element of neuro-linguistic programming (NLP), a method of enhancing people's lives using psychological techniques.
An important aspect of NLP involves teaching people about the relationship between their eye movements and their thoughts.
According to the theory, when right-handed people look up to their right they are likely to be visualising a "constructed", or imagined, event. In contrast when they look to their left they are likely to be visualising a what is known as a "remembered" memory. For this reason, when liars are constructing their own version of the truth, they tend to look to the right.
The idea was tested by filming volunteers and recording their eye movements as they told the truth or lied. A second group of volunteers was then asked to watch the films and try to detect the lies by watching the eye movements.
Prof Wiseman, a psychologist from the University of Hertfordshire, said: "The results of the first study revealed no relationship between lying and eye movements, and the second showed that telling people about the claims made by NLP practitioners did not improve their lie detection skills."
A follow-up study involving analysing videos of high-profile press conferences in which people appealed for help in finding missing relatives, or claimed to have been themselves the victims of crime.
While some were telling the truth, others turned out to be lying. There was no evidence of a correlation between lying and eye movements.
Co-author Dr Caroline Watt, from the University of Edinburgh, said: "A large percentage of the public believes that certain eye movements are a sign of lying, and this idea is even taught in organisational training courses.
"Our research provides no support for the idea and so suggests that it is time to abandon this approach to detecting deceit." The research appears in the online journal Public Library of Science ONE.Reuse content