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Last Updated: Friday, 15 October, 2004, 07:07 GMT 08:07 UK
Select few 'can identify liars'
Lie detection machine
Traditional lie detection machines are only about 70% accurate
A select group of people have a unique ability to spot when someone is lying, US research shows.

A University of San Francisco study found only 31 people out of 13,000 could identify in nearly all cases when someone was lying.

The group used facial expressions, body language and ways of talking and thinking to spot liars while the others did little better than chance.

The team are now using them to help train police and other investigators.

In the tests, during which the participants were shown video clips of people, the select group, dubbed wizards, were able to observe a few seconds of footage and detect lying.

Our wizards are attuned to picking up 'micro-expressions'
Dr Maureen O'Sullivan, of the University of San Francisco
The study said the wizards had a "natural talent" although they were highly motivated and tended to be older.

Police, lawyers and FBI agents were all among the groups who were unable to tell if people were lying.

The wizards' success rate was even higher than the traditional polygraph test, which is used in the US and is claimed to have a 60% to 70% success rate.

Dr Maureen O'Sullivan, the university's professor of psychology, said: "We hope that by studying wizards, we'll learn more about the kinds of behaviours and ways of thinking and talking that can betray a liar to an experienced interviewer."


She said that even though people may try to control their expressions, most are not able to keep their feelings from showing on their faces.

"Some of the muscles involved in expressions are not under conscious control.

"Especially when we feel strong emotions, those expressions appear on our faces, even if only for a fraction of a second.

"Our wizards are attuned to picking up 'micro-expressions'."

By analysing how the wizards spot liars, Dr O'Sullivan's team has developed a training course to help people become better lie detectors.

The course stresses the importance of emotional clues and cognitive clues, such as inconsistencies in the way people are talking.

But Aldert Vrij, professor of social psychology at the University of Portsmouth, who has written books on lie detection, cast doubt on whether people possessed the ability to spot liars.

"People who lie react differently when they lie so there is no set pattern. They can feel afraid, guilt or excitement while lying, it really depends on the person.

"And even if a select group are able to tell if people are lying, will they be able to explain how they do it?"

Police consider lie detector tests
14 Apr 03  |  England
Report gives polygraphs the lie
08 Oct 02  |  Technology
How accurate are lie detectors?
22 Aug 02  |  Science/Nature

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