Knowing when somebody is lying to you has become almost a science. Many law enforcement agencies from the FBI down to local police departments offer training in this subject. Observation and common sense play a large part.
Typical of using common sense; might be a situation where police are questioning a suspect about a crime. The suspect starts to yawn, stretch their arms and legs, and trying to get comfortable. They might even try removing imaginary pieces of lint from their clothing. In other words they are trying to show by body language that they are calm and relaxed because they are innocent. The truth is, if they were innocent they would not be relaxed, but angry and indignant at being wrongly accused.
Here is a way to tell if a person is doing something wrong. As example we will use a girl who thinks her fiancé is running around with other women. She should not ask him directly because he would simply deny it and nothing would be accomplished. The better approach would be for her to say, ” I saw my girl friend’s fiancé out with another woman. What should I say to her? ”
If the girl’s fiancé responds by trying to get rid of the question as quickly as possible by saying things like, “You should mind your own business. Let’s go out to a movie.” or” I hate talking about things like that ” or “Forget it.” the probabilities are he is running around and feels uncomfortable talking about it. On the other hand if he is willing to talk about it, discussing the best way to tell the girl about her fiancé as example . This indicates that he is not running around because he is comfortable talking about the subject.