Why People Are Better At Lying Online Than Telling A Lie Face-to-face
offering up a fib in person might make you provide certain signals that you’re trying to deceive, but lying online avoids the physical cues that can give you away.
“When people are interacting face to face, there is something called the ‘motivational impairment effect,’ where your body will give off some cues as you become more nervous and there’s more at stake with your lie,” says Woodworth. “In a computer-mediated environment, the exact opposite occurs.”
Lying? The Face Betrays Deceiver's True Emotions, But In Unexpected Ways
The face and its musculature are so complex—so much more complex than anywhere else in our external bodies
unlike body language, you can’t monitor or completely control what’s going on your face
researchers were able to discern rare “microexpressions,” flashes of true emotion that show briefly, from one-fifth to one-25th of a second, on the faces of participants when instructed to deceive
clipped from: www.sciencedaily.com 
