If you think someone has knowledge of someone or something specific, this technique can be used to help you find the truth. It works on this psychological principle: A person is drawn equally to that which he has no prior knowledge. Simply put, if a person has never heard of Fred, Peter, and Marvin, his interest in them will be uniform. However, if he knows Marvin, but not the other two, then he will pay more attention when Marvin's name is mentioned, in contrast to the other names.



This technique presents the person with multiple forms of information. If his interest moves unevenly in one direction, then it is likely that he has an awareness of certain information that he has not thus revealed to you. Here's how it works:

A personnel manager thinks Jimmy may be planning to leave the company and take a list of clients with him. He suspects Jimmy has already met with "Mr. Black", the owner of a competing company. Therefore, the manager simply sits Jimmy down and casually puts three folders on the desk labeled Mr. Green, Mr. Blue, and Mr. Black. If Jim has met, or is planning on meeting with Mr. Black, his gaze will fix longer on Mr. Black's file than on the other files. Alternatively, Jimmy's gaze will become mechanical and awkward; unsure of where to look, he will take-on a very visible unnatural posture.

Another way to apply the technique is by merely talking about the situation and listening for his focus. First, state all the facts, as you both know them to be. Then, switch one of them. If his attention goes to the switched fact, then you know conclusively he is aware of the situation itself.

For example, let us say a detective is interviewing a suspect about a robbery. He reads from the report, telling his suspect exactly what happened, except he switches a key point about the facts of the crime. If the suspect is guilty, his attention will instinctively go to the key point. What he hears surprises him. He wants to be sure he heard you right, and he will use the “inconsistency” as a reason why he could not have committed the crime. The only way he would know to focus in on one “fact” would be if he did commit the crime. If he is innocent, then all of the details are unknown to him, and so he is incapable of separating them into categories of true or false. Let us see what this dialogue sounds like in action:

The detective reads off the “facts” to his suspect, as he knows them. “The suspect shot the teller .. . left in a green sedan with California license plates .. .[then add one piece of false information] crashed into another car .. . got out, jumped over a fence, and got away.” If the suspect is guilty, he will question the incorrect detail: “crashed into another car? My car doesn't have a scratch on it. It couldn't have been my car!” His proof, as to why he is innocent, uses the one false piece of information; by doing so, he reveals he knows the whole story.

This article is based on techniques from Dr. David J. Lieberman's latest book, YOU CAN READ ANYONE, and is available in paperback or as an e-book wherever books are sold.