Studying Liars Part I

by Paul Francois & Enrique Garcia

Any article of this nature, must begin by acknowledging that no article, or book for that matter, is all encompassing when it comes to detecting deception in human beings. The human brain is so complex, there's no way to contain its vastness on the written page. After having conducted several hundred criminal interviews and interrogations, however, we would like to recount some of the more common deceptive indicators we have seen over the years. While not an exhaustive list, these verbal and non-verbal signs of deception are more common than some of the others we've seen.

In any evaluation of deception in human subjects, there are a couple of important ground rules to establish. The first, is that you must clearly ascertain the subject's baseline of behavior when he is telling the truth. What does he look like and sound like when asked and responding to non-threatening questions such as his name, address, work history, and other such personal and biographical information. Secondly, because it is a stressful situation for the subject to lie to the interviewer (because he risks getting caught, losing his job, going to jail, embarrassment, etc.), we must train ourselves to look for the stressful indicators. We want to look for these indicators within 3-5 seconds of the stimulus, i.e. the question or conduct on the interviewer's part that causes the subject to react. It is within this small window that the verbal and non-verbal indicators of deception are most reliable for evaluation. Finally, we are looking for clusters of two or more of the following deceptive indicators when evaluating the response. Because this is not an exact science, requiring two or more deceptive indicators to safely rule an answer deceptive is our safeguard against false indicators.

Verbal Indicators
The skillful interviewer knows that the verbal part of the lie is the easiest part of the lie to project. It can be rehearsed and practiced repeatedly prior to the interview and can therefore be more difficult to spot. Because the subject is under the extreme stress of getting caught in his lies, he will subconsciously reveal his stress to us in certain patterns, as follows:

No Response/Non-Responsive
You ask the subject a question and he offers no verbal response whatsoever. He does not want to bog himself down by committing to a particular answer and therefore avoids the question entirely. Another, craftier variation of this, is offering an answer that is non-responsive to the question. For example you ask the subject, "Why did you kill that old man?" and he responds, saying, "You guys are all the same. You think just because I've served some State time that I'm good for this too." Not only did the subject completely avoid answering the question directly, his response also lacked a strong, affirmative denial.

Delayed Response
You ask the subject a question and he goes outside of his normal baseline and delays in answering you. It is the deceptive subject, not the truthful one, who requires more time to think of his response.

Repeating the Question
When asked a question, the subject repeats it-often verbatim. Here, the subject clearly heard what you said, as evidenced by his duplication. He is buying himself time to ponder his next move and his best response. Again, it is the deceptive person who must calculate his answers. The truthful person does not take such pains as he inherently recognizes that the truth is its own defense.

No Denial
You ask a pointed and accusatory question and the subject fails to deny his involvement. This can be done in very cleverly subversive ways. For example, you ask the subject, "Joe, if you had anything to do with this you should tell me now," and he responds, "If I had anything to do with this I would tell you." Notice that the subject's response lacks an important component-a denial of involvement. The truthful person would more likely respond by directly stating, "It wasn't me. I'm innocent."

In Part II, we will examine two of the more complex verbal indicators of deception - Overly Specific Responses and Protest Statements.