This Man Knows You're Lying: He Explains How

Have you noticed that when you are trying not to laugh, you suck your cheeks in? Chances are, the smile ‘leaked’ onto your face for less than half a second. This is called a micro expression, and Dr Mark Frank, a world-renowned expert in non-verbal communication, has been studying them for years. He can read suppressed emotions just by observing your facial cues - your eyebrows and lips being the main culprits that will give you away when you’re lying.