The study, published in the‘Journal of Non-verbal Behaviour, found that 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 at Portsmouth University.

The researchers say that 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.

According to the report in the Mail online, it means that blink rates could be used by professionals to catch liars.

Experimenters undertaken for the study 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 in a sudden flurry of activity, while that of the truth tellers remained the same.

“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.