By studying large groups of participants, researchers have identified certain general behaviors that liars are more likely to exhibit than are people telling the truth. Fibbers tend to move their arms, hands, and fingers less and blink less than people telling the truth do, and liars’ voices can become more tense or high-pitched. The extra effort needed to remember what they’ve already said and to keep their stories consistent may cause liars to restrain their movements and fill their speech with pauses. People shading the truth tend to make fewer speech errors than truth tellers do, and they rarely backtrack to fill in forgotten or incorrect details. [emphasis added]
“Their stories are too good to be true,” says Bella DePaulo of the University of California, Santa Barbara, who has written several reviews of the field of deception research.
Liars may also feel fear and guilt or delight at fooling people. Such emotions can trigger a change in facial expression so brief that most observers never notice. Paul Ekman, a retired psychologist from the University of California, San Francisco, terms these split-second phenomena “microexpressions.” He says these emotional clues are as important as gestures, voice, and speech patterns in uncovering deceitfulness.
And a (scant) few people can serve as super lie-detectors:
O’Sullivan now says that her further studies of federal agents, forensic psychologists, and other groups of professionals indicate that a very small percentage of people are extremely good at spotting a phony. “We always found one or two people who were very good,” she says.
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