1. Is her face giving it away?
You may think a smile can easily disguise your true feelings, but the expressions that flash across a liar’s face will give away what she’s really thinking—whether she knows it or not. Experts advise paying close attention to hard-to-hide micro-expressions; these clues are often so difficult to detect that even trained experts have trouble discerning them. But you may be able to spot a liar by the red color on her cheeks, since anxiety can cause people to blush. Other indicators of lying? Flared nostrils, lip nibbling, deep breathing, and rapid blinking, which hint that the brain is working overtime.