HT, Patna 23-08-2008
You can catch a liar by how fast they blink
London Aug 22 -- A fascinating study has suggested that if you want to know if a person is telling the truth, keep an eye on the eyes, for liars blink in different ways during and after a falsehood.
The study found liars blink less than normal during the lie, and then have a flurry up to eight times faster than usual afterwards.
"It is striking what different patterns in eye blinks emerged for liars and truth tellers," said Dr Sharon Leal, co-author of the study.
The researchers said the increased mental effort involved in telling fibs could be the reason why liars do not blink during the act of lying.
"Liars must need to make up their stories and must monitor their fabrication so that they are plausible and adhere to everything the observer knows or might find out," Dr Leal said.
Experimenters found that when questions were being asked and the answers given, the blink rate in the liars went down. Afterwards, the blink rate of the liars increased rapidly, while that of the truth tellers was unchanged.
"Liars must remember their earlier statements, so that they appear consistent when re-telling their story, and know what they told to whom. Liars will be more inclined than truth tellers to monitor and control their demeanour so they will appear honest," said Leal.
The flurry of blinks after the lie "was a kind of safety valve, like a release of energy after the tension of lying," he argued.
