When a person fakes an emotion, their face often betrays them, because they may only show emotion on the upper or lower half of their face. For example, if someone is smiling, see if this emotion carries to their eyes. Similarly, if someone is crying, does this emotion seem consistent with the expression on the lower half of their face? Keep in mind that a pathological liar will not show emotion as a giveaway that they are lying. Many liars have their stories lined up for questions that they anticipate. When you throw them a curveball by asking something unexpected, they might not have an appropriate response.  For example, if the person says that they went to eat at a particular restaurant, they might anticipate that you’ll ask about their food, the waiter, and how much the meal cost. But they might not expect a question about where the bathroom was located. Pathological liars enjoy additional questions, so this might not always be a helpful indicator. Microexpressions are very minor facial movements that capture a person’s true feelings. These are fleeting emotions, sometimes lasting for as little as 1/125th of a second.  Microexpressions will indicate emotion, but they do not necessarily give you clues as to why the person is feeling that emotion. For example, a lying person might show fear in a microexpression because they are scared they will be caught. But a truthful person might show fear in a microexpression because they are scared that they will not be believed. Keep in mind that pathological liars are very good at hiding their emotions, so this might not be something you can always use to spot lying. Sometimes a person will say one thing and their body will react in another way unintentionally. For example, they may answer yes to a question, but his head may shake side to side, indicating no. Keep in mind that nonverbal cues vary widely from person to person. What you recognize in one person may not translate to another person.
لاحظ إذا كان وجهه يعكس مشاعره. اطرح سؤالا غير متوقع من الطرف الآخر. لاحظ أدق تعبيرات الوجه. لاحظ الاختلاف بين اللفظي وغير اللفظي.