text: That brings me to my next example, interigation. imagine you have 8 people who have been caught and there was a murder. If you ask all 8 of them I garantee you will figure out who murdered the person. In paragraph 7, line 12, the text states, "They even indicate the difference between a genuine smile and a forced one." This can tell you if a person is lying or not, along with a couple other factors. Lets say someone is being asked a couple questions, if they asked the person if he broke into a house recently they can tell if his stress levels are high.