Eyes darting back and forth
"This is a physiological reaction to him feeling uncomfortable or trapped by your questions that he doesn't want to answer," Bouton says. "It's a throwback to when people had to seek an escape route when they feared they were in a dangerous situation, such as facing a human or animal adversary."
Rapid blinking
"A person will ordinarily blink about five or six times a minute, or once every ten or twelve seconds," Bouton says. "When stressed — for instance, when someone knows he's lying —he may blink five or six times in rapid succession."
Bouton says exceptions to the usual blink rate mostly have to do with production of dopamine in the body. For example, a person with Parkinson's disease will have a noticeably slower blink rate than what is usual, while a person with schizophrenia will blink more rapidly than normal.
Closing eyes for more than one second at a time
Bouton says that when a person closes his eyes for a second or two, this may indicate he's lied to you, since this is a type of defense mechanism. Normally, he explains, a person will blink at a speed of 100 to 400 milliseconds, or 0.10 to 0.40 of a second.
Looking up to the right
"When you ask a normal, right-handed person about something he's supposed to have seen, if he looks upward and to his left, he's truly accessing his memory of the incident," Bouton says. "However, if he looks upward and to his right, he's accessing his imagination, and he's inventing an answer."
Bouton says that left-handed people will usually have just the opposite reactions.
And some people will stare straight ahead when trying to recall a visual memory, he says.
Looking directly to the right
"If you ask about what a person heard, his eyes will shift toward his left ear to recollect the sound he heard, but if his eyes shift toward his right, he's about to fib," Bouton says.
Looking down to the right
"His eyes will shift downward and to his left if he's going to tell you his memory of a smell or touch or sensation, such as a cold draft or a terrible odor," Bouton explains. "But his eyes will shift down and to his right if he's going to lie."
Bunched skin beneath and wrinkles beside the eyes
Bouton says that when people genuinely smile, the skin around their eyes bunch and wrinkle.
Face touching
Bouton explains that a chemical reaction causes people's faces to itch when they lie.
Pursed lips
"A person's mouth will often go dry as she's lying," Bouton says. "She may do a sucking motion, pursing her lips, to try to overcome this."
When their lips are so tightened that they appear pinched and white, this can indicate lying.
Excessive sweating
Bouton says sweat may appear on the forehead, cheeks, or back of the neck, and you'll likely observe the person try to wipe it away.
