This question originally appeared on Quora.
Answer by Tim Dees. Tim is a retired police officer and freelance writer. He is a columnist at PoliceOne.com, a member of the Public Safety Writers Association, and the author of The Truth About Cops.
One issue I see repeatedly is the use of a single behavior to "prove" deception, anxiety, surprise, etc. Here's an example of Patrick Jane accusing a man he has never previously met of lying, after watching him speak for only a few seconds:
There is a school of interview and interrogation called kinesic interviewing.The interviewer is trained to watch for behavioral cues that indicate the same sort of behaviors that Patrick Jane is trying to identify. A critical aspect of this technique is not to bet the bank on any single cue. For example, one cue I've read about (and that has been disputed just as often as advocated) is that a person formulating a deceptive statement will look down and away from their dominant side in what is sometimes called a "microexpression." The rationale behind this is that the eye movement is linked to accessing the creative portion of the brain, as opposed to the memory center. The interviewee who looks down and left (if right-handed) is thinking up a plausible lie, while the person who looks up and right is trying to recall details from a real memory. I need to emphasize here that there are as many people who think these eye movement cues are hogwash as there are those who believe them to be reliable.
Everyone you know has their own unique set of mannerisms and gestures. A good mimic can detect and replicate these, and you will instantly know who they are imitating. Any reliable assessment of deception by way of microexpressions and body language has to include a non-stress interview to assess what are normal, non-deceptive behaviors from that person. Patrick Jane seldom observes anyone for a long enough time in a conversational setting to obtain that baseline.
Second, it's entirely possible that someone's normal way of speaking includes one of the classic indicators of deception, even if they are telling the truth. I worked with one man who never made eye contact when he was speaking to you. He was forever scanning all around, looking down briefly now and then to see if you had walked away or fallen asleep. His nickname was "Wall-eyed Wayne." He would have been a real trial for someone assessing his indicators of deception based solely on the classic cues. In the example above, the "supplication gesture" might just be the way this man talks. Of course, because it's necessary to the story line, Jane is right on the money about the guy and his lie.
Instead of relying on a single indicator of deception, you instead look for clusters of behaviors, which can include rapid eye movement, blinking, frowning or smiling, hand gestures, body positioning, shifting in a chair, etc. When key questions cue this cluster of behaviors repeatedly, the interviewee is, at minimum, anxious about the content of the answer, if not speaking deceptively altogether.
A skilled liar works out the lie before he tells it and relates it convincingly. The only way you'll get physical cues of deception out of them is if you interview them until they are fatigued and they find it difficult to maintain the front. In a police interview, the person being interviewed controls the duration of the interview (although they may not know this). If they want to end the interview, all they have to do is say they don't want to answer any more questions until they have consulted with their attorney. Even if the attorney is present, no one but the two of them can say how long this consultation will require or when they might come to a decision as to how to proceed. What usually makes the system work for the police is ego. The subject believes he can outlast and outwit the interrogator. If the interrogator is savvy enough to get the subject to let their guard down and reveal some inconsistencies, they can chip away at the lie and expose them.
Skilled con men are, in fact, good at reading people, but they seldom know why or are able to itemize the cues that make them successful. One personality type most people know is the "ladies' man" who seems to be able to talk almost any woman he meets into bed. When his needs have been satisfied, he will no longer give his victim the time of day. Most of these guys can't tell you exactly how they do it, only that they can (and they will boast of it and win bets of their prowess). These people are nothing more than good con men, and the lists of their conquests are testimony that most people (not just women) are their prey for the taking.
A show, now off the air, that operated with a similar premise was Lie to Me, starring Tim Roth. Here's an overview of what it was about:
Roth's character Cal Lightman is supposedly the world's foremost expert on indicators of deception, and maybe someone operating at that level of expertise can determine reliably when someone is lying, and how he knows it. I doubt that someone like Patrick Jane, trained in his craft by his con man father, would have that level of skill.
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