Archive for the ‘Beat the polygraph?’ Category

Polygraphs Don’t Detect Lies; Polygraph Examiners Do

January 3, 2010

The polygraph is not a lie detector.  It is an instrument that measures and monitors parts of your body’s physiology.  It does nothing more and nothing less.  The polygraph examiner, however, can tell whether a person is lying or telling the truth by carefully evaluating physiological changes that the polygraph is monitoring.  For all practical purposes, the polygraph examiner is the lie detector.

The accuracy of any polygraph test depends entirely on the skill, knowledge and experience of the examiner.  If the examiner knows what he is doing, and does it well, the results of his tests will be accurate almost all of the time.  If the examiner doesn’t really know what he is doing, or if he conducts the test poorly, the result (pass or fail) will be totally meaningless.

Dr. Rovner is a polygraph examiner with a private practice in Los Angeles, California.

Psychopaths Can’t Beat A Polygraph Test

October 5, 2009

Polygraph examiners test psychopaths all the time.  Psychopaths make up a large segment of the criminal population (including white-collar criminals).  Many of the personality traits of a psychopath lead some people to believe that they can “beat” a polygraph test at will.  Psychopaths are pathological liars, they don’t have any remorse or guilt for their crimes or empathy for their victims, and they don’t accept responsibility for their own actions.  They’re not particularly concerned about the bad things that they do, especially when those bad things bring them money or power.

 How do we know that psychopaths can’t beat a polygraph test?  We do a little scientific research.  One of the handy things about research is that it cuts through theoretical arguments and gets down to the essential basic question which, in this case, is “Can psychopaths pass a polygraph test when they’re lying?”

 The answer to that question is a resounding “No”.  Research scientists have published the results of experiments in journals such as Psychophysiology, The Journal of Applied Psychology, and The Journal of Research In Personality.  In all of these studies, we find that psychopaths and others with antisocial personalities are detected in their lies at the same rate as everybody else.  In fact, some of the physiological reactions of psychopaths are actually stronger than other people when taking a polygraph test.

 So, how do we explain this counterintuitive reality?  Psychopaths may be pathological liars, but they have the same fear of detection and its consequences as anybody else.  The reactivity of our autonomic nervous system is so strong that it simply can’t be overridden, even by somebody with no conscience.

Dr. Rovner is a polygraph examiner with a private practice in Los Angeles, California.

No One Can Beat A Polygraph Test

September 30, 2009

Since the beginning of polygraph testing, people have tried to “beat the polygraph” by using a variety of physical and mental techniques, called countermeasures.  Although the idea of passing a polygraph test when one is actually lying is appealing to some people, research has shown that countermeasures are completely ineffective.  In fact, two major research studies have demonstrated that reading about polygraph techniques and countermeasures is futile for someone hoping to beat the test (Rovner, 1986; Honts, C.R. & Alloway, W.R., 2007).

Several people who have websites claim to be able to teach a guilty person to use countermeasures that will enable him to fool a polygraph examiner into believing that he is innocent of the crime or activity for which he is being tested.  Even if we overlook the fact that most of the people who own these websites are not polygraph examiners, the idea of fooling a trained and experienced examiner is ridiculous.  These internet “experts” are telling their readers that a person who has never taken a polygraph test can quickly and easily learn more about polygraph techniques and psychophysiology than an examiner who has conducted thousands of tests. This is like telling someone that by reading a book about golf he can go out and beat Tiger Woods in his first match.

The reality of the situation is that the polygraph testing environment is new and foreign to most examinees.  The novelty of that environment, along with the importance of the test results, will undoubtedly produce anxiety and apprehension in anyone.  With that nervousness as a backdrop, the examinee must learn, understand, remember and flawlessly execute certain psychological and psychophysiological moves if he is to successfully fool the polygraph examiner:

    ● He must know everything the examiner knows.

    ● He must be prepared to respond appropriately to any technique that the examiner is  using (there are several different techniques.)                                       

   ● He must not reveal any damning information during an extensive pre-test   interview.

   ● He must be able to produce a certain repeating pattern of physiological reactions several times in each question sequence, and replicate those reactions in each of three to five repetitions of the question sequence.                               

The absurdity of the situation is obvious.  Beating a polygraph test is simply too complex an undertaking for anyone.

Now, it’s true that any person can be taught to produce physiological responses at will.  For example, biting one’s tongue will induce small changes in blood pressure and heart rate.  However, the abnormal physiological reactions of someone using countermeasures are much different from the natural responses of someone who is simply answering questions.  A skilled and experienced polygraph examiner won’t be fooled by such childish games.

Louis Rovner, Ph.D.


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