Microexpressions pop up extremely briefly, ranging from 1/5 to 1/25 of a second in length, so most people don’t pick up on them without training. Ekman came up with seven standard expressions and their key components to look for when trying to figure out how the person you’re speaking with really feels.
Anger’s not too hard to recognize—furrowed eyebrows, a frowning mouth, chin jutting out, and narrowed eyes all suggest that the person’s mad.
Beyond microexpressions, there are a few telltale signs that someone’s not being genuine. For example, most real expressions last a few seconds—four or five, tops. If someone’s huge smile or scared look lasts longer than that, it’s suspect. Some also believe that eye movements during story-telling say something about truthfulness. Eyes moving upward and to the right when explaining something might mean the person’s searching through his or her brain bank for details, whereas looking up and to the left suggests a deceptive tale. (This would be reversed if he or she’s left-handed.)
One Piece of the Puzzle
Even the most educated experts at lie detection can’t get it right every time and that’s because humans are complex creatures with a multitude of mannerisms that vary in meaning. We can learn to recognize facial expressions—and even to see the flashes of expressions that give away our inner thoughts—but that alone won’t tell us what’s behind the hidden emotions.