text: Some people will argue that students won't be truthful and they will just make it a joke. The Facial Action Coding System can tell if you are being truthful or not. For instance, the article says, "in a false smile the mouth is stretched sideways, using the sygomatic major and a different muscle, the risorius. Faces don't lie. These muscles are sometimes used to spot when a "smiling" politician or celebrity is being truthful."