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Pitfalls of the Lie Detector Part 4

Pitfall #4  - Attorneys Wanting to Clear Their Clients

I must admit that I never understand it when defense attorneys are so stupid or naïve that they will encourage their clients to submit to a stipulated polygraph exam whose results can be used in court.   There is a good reason that polygraph results are inadmissible - they are no more accurate than flipping a coin (57% according to scientific studies).

The test subject basically is waiving his or her rights to have their attorney physically present when they are being examined.  Remember that a polygraph examination is indeed an interrogation.  I have seen “attorneys present” but they are not even in the same room, as they may “influence” the outcome of the examination.  What attorney in their right mind would have their client give up such a right?

You need to understand that a polygraph examination is not some sort of objective observer, making notations from a scientific device and recording their observations of the device and the subject.  This is how polygraph examinations are sold and marketed.  Yes, an examiner does observe the device’s readings, and does observe your behavior.  However, the test is completely subjective based upon what the examiner decides. The polygraph industry in the United States has done an excellent job of perpetrating the myth that polygraph exams are just a benign scientific pursuit of the truth.  Most people don’t realize that polygraph examiners are much more likely to see guilt where a truly disinterested and objective person might not.

Once again – there really is not a “pass” or “fail” to a polygraph exam. What may happen is that the victim of the scam or in other words, the person being tested “confesses” to some sort of indiscretion.  Once the suspect “fails,” the exam (once again – the subject giving some sort of confession), the examiner can testify that the suspect showed signs of deception.  The examiner can also say that the subject made incriminating statements and that they exhibited body language suggestive of guilt.

Even if the subject “passed” the exam, the examiner can testify that they used some kind of tongue biting techniques or similar counter-measures to trick the polygraph. Because of all of this, polygraph exams are the kiss of death for an innocent suspect, and many who have taken one plead guilty rather than face having the polygraph results used against them.

The bottom line is that polygraph examination results are only an opinion of the examiner, nothing more.  They may even include lines like “The polygraph data was analyzed by computer with an algorithm developed in the Applied Physics Laboratory of Johns Hopkins University.  By computer, the data was evaluated to be truthful (or deceptive depending upon the test). The probability of Mr. Test Subject intended to deceive regarding questions (number of the relevant-issue questions) is measured to be __%.”  Just analyze the statement.  First of all, what does physics have to do with anything concerning lies?  Secondly, it has to based upon an assumption that people react to telling lies by increases in blood pressure, breathing rate and heart rate.  Thirdly, wouldn’t it be a biological or anatomy lab that would come up with said algorithm?  I think it is because when we throw physics together with computer analysis, it sounds so scientific that it has to be scientific!  See – it is just a marketed software program that is used by examiners, so they can claim objectivity.

The thing is that it is never in one’s own best interest to take a polygraph exam.  Even when you get peer pressure, or pressure from “the press” or anyone else, it is not in your best interest to take an exam.  I understand that the myth of the lie detector is completely bought by the American press.  That is why people will ask the dumb question “are you willing to take a lie detector test?”

Too many times, a person will often say that they have discussed their willingness to take a lie detector test with their attorney when the attorney evidently failed to keep them from participating in such foolishness.

I guess a possible exception to being in one’s best interest, is when it is under terms of attorney-client privilege. If the client doesn’t pass, the public will never hear about it, and his lawyer can have him or her be administered a polygraph examination by someone else until he does pass. Then his lawyer can announce to the world that his client has passed a polygraph.  While this is all good for newspapers, it never exonerates the client.


Whatever you do – stay safe!


Pitfalls of the Lie Detector Part 3



False Confessions: they happen.  False confessions have figured in 24 percent of the approximately 289 convictions reversed by DNA evidence.  The question is why? 

If you have never been interrogated, tortured, locked up, or verbally threatened, you may find it hard to believe that anyone would confess to something they have not done. As a matter of fact, most jurors find it hard to believe that people make false confessions.  The average person believes that innocent people do not make false confessions. People will make false confessions. I know this for a fact to be the case.

So what in the name of God is the motivation for making a false confession? Do they want to stop the abuse? Do they want to be seen more favorable by interrogator? Do they think that somehow confessing will lead to their freedom?  Do they just want the interrogation to end? The answer to all of these is yes.


Studies by psychologists on confessions that have been proven false, show that often these “confessions” are done by the following: children, mentally ill, mentally retarded, and suspects who are drunk or high.  What do these all have in common?  They are susceptible to suggestion, eager to please authority figures, disconnected from reality or unable to defer gratification. Many of these types think that they will be jailed as long as they keep up their denials and the will be released if they go along with interrogators.

This does not mean that regular adults of normal intelligence do not confess falsely after being manipulated. The biggest manipulator I know, when it comes to getting confessions, is the polygraph exam (or examiner).  I say manipulation, because the polygraph exam is deceptive by nature. The examiner gets you to relax, then later applies the psychological thumb screws.  A polygraph examination is an interrogation.

Polygraph examinations are known to cause false confessions. Despite the fact that the inaccuracy of the poly graph is well documented, police often rely heavily on the “lie detector.”   What most civilians do not know, is that it is either being used as a short-cut on an investigation, or it is used because the case has stalled or there is a lack of evidence to point to a particular suspect. If an innocent suspect “fails” the polygraph exam, police will use the results to persuade him or her that they must be guilty.   (see Part 2 for how this is usually done)

First of all, there is no such thing as “failing” a polygraph examination.  This is another lie told by examiners or law enforcement in their ploy to get a “confession.”  Most examiners will avoid using this term because it is not “professional” they will say things like “the subject showed signs of deception” and the like. Once again, there is no pass or fail to a polygraph examination.  However, if they get you to confess to something, you have failed yourself in a big way.

What most people who are innocent do not understand, is that a polygraph exam cannot and will never prove you are telling the truth.  You cannot exonerate yourself by taking a polygraph exam.  Remember that in reality, there is no passing or failing a polygraph exam. People get duped into “proving their innocence” with a lie detector test. This technique is nothing more than investigators putting emotional pressure on the person from whom they want to get a confession.  Note that “passing” a polygraph exam will never eliminate you as a suspect.

Remember – whatever you do – Stay Safe!

Pitfalls of the Lie Detector Part 2


Pitfall#2:  Polygraph examinations are based on a lie.  Well, really like a series of lies.

There have been no significant changes in the polygraph exam in  50 years.
One of the big pitfalls of lie detectors is that examinations are totally based upon deception by the examiner.  One thing the examiner will never admit to is that any and all “examinations” are interrogations.  Any interrogation is by nature confrontational and accusatory.  The examiner will not be honest with you about the methods being used on you.  You are being played right from the beginning.  You need to understand that the main objective of the polygraph exam is to extract damaging admissions from you.  If you admit to anything damaging the examiner will automatically deem that the examination was a success, and that you were deceptive.  This is the case whether you were deceptive or not.

In light of the above, if you are ever required to submit to a polygraph test (and hopefully you are not naïve enough to do this voluntarily) never, ever admit to any wrong doings or confess anything to the examiner or based on the examination.  Remember this: anything you say during a polygraph screening interrogation can and will be used against you. But guess what - unlike during regular criminal interrogations, our government denies you the right to have legal counsel present at a polygraph screening interrogation.  Just knowing that should be enough to keep you from ever volunteering for an examination.

Do not let them fool you – they (the examiners) are not that good at judging deception any more than any field investigator with a moderate amount of experience.  In reality, they probably are less reliable. How can I say that? In a test of 1,141subjects given polygraph examinations, less than 60% of these tests resulted in a correct decision rendered… (both) guilty and innocent.

So the facts are that polygraph examinations are just a little better than a 50/50 guess.  That is the scientific fact concerning these examinations.  But let’s look a bit more at some of the deception that goes on in some of these examinations.  In case you were wondering, results for blacks being examined are even worse!

Many (maybe all) examiners will use the polygraph as an interrogation tool. Almost always there is a “follow up interrogation” after the exam.  What they do is they ask subjects to explain why certain questions on the screening test might have disturbed them enough to cause a noticeably different response. This is where the examiner starts bluffing the test subject into giving some sort of damaging confession. In the stressful context of the polygraph examination, many people make the mistake of confessing damaging admissions. The people being examined often hope that after their conscience has been purged, they are thinking the polygraph will pronounce them truthful.  Little do they know that at that point it is too late. The problem is that these admissions and not the polygraph results are what almost always are used as the basis for not being recommended for employment.

All confessions to wrong doing – no matter how insignificant, are considered a “trophy” for the examiner.  They will all say that confession is “proof” for the examination.  So, to repeat myself, never, ever admit to any sort of wrong doing in a polygraph examination. The smallest thing you admit to will be blown out of proportion.  This will have serious adverse career consequences.

Remember, whatever you do, Stay Safe!

The Pitfalls of the Lie Detector Part 1


Before anyone jumps on my case, I know that there is no “lie detector” but only a polygraph.  I understand the basics of how it works and the nature of the questions.  What this post is about is the idea that there are basic pitfalls in putting emphasis on the polygraph.

Pitfall #1:  Using the polygraph for pre-employment screening.  The reason this is a pitfall, is that this is actually the worst possible use of a polygraph.  The National Academy of Science studied the use of polygraph examination to determine if they were effective on screening security risks.  They found of course that they are not.   Specifically, they said “Basic science and polygraph research give reason for concern that polygraph test accuracy may be degraded by countermeasures, particularly when used by major security threats who have a strong incentive and sufficient resources to use them effectively. If these measures are effective, they could seriously undermine any value of polygraph security screening.” The real and important question to ask then is why does the government rely heavily, almost exclusively on the polygraph for security clearance?

What the National Academy of Sciences found was this: “There has been no serious effort in the U.S. government to develop the scientific basis for the psychophysiological detection of deception by any technique, even though criticisms of the scientific grounding of polygraph testing have been raised prominently for decades. Given the heavy reliance of government on the polygraph, especially for screening for espionage and sabotage, the lack of a serious investment in such research is striking.”

Now polygraph practitioners, or “examiners” will staunchly claim the validity and veracity of polygraph examinations.  Of course they do, this is their bread and butter.  Anyone that can be swayed by their arguments in reality is actually just gullible.  The whole essence of the use of polygraphs is the mystique that surrounds them.  Examiners and practitioners keep the way they operate the polygraph a closely held secret – supposedly so that people cannot learn to “beat” the polygraph.  As a matter of fact, if the examiner even merely suspects that the person being examined is using or attempting to use counter-measures – they are automatically assumed to be showing deceptive behavior.

The pre employment screening examination has to make the following assumption: that a person who is deceptive about certain undesirable past acts is at risk for committing different kinds of undesirable acts in the future.  First of all, there is absolutely no empirical scientific evidence that this indeed is true.  Secondly,  the examiner always can be totally subjective in their conclusion that the subject was deceptive.

There is a  simple fact that the “accuracy” of a particular examination depends upon the purpose of the test. This makes it unwise to assume that “accuracy” estimates calculated from data when the polygraph is used for a specific purpose, such as finding a perpetrator of a particular crime, can be in even the remotest way be applied to its use for pre-employment screening.  I put the accuracy in quotes, as whenever an examination takes place, and the examiner tells the subject that (s)he thinks the subject is deceptive on something, and then gets a “confession” the test is considered accurate and a success.  It does not matter if the confession was even true, real, or accurate.

Most of these tests are based on the principle of the “Control Question Test” or CQT. As you may or may not know, for the CQT to be valid, you first have to make two assumptions. If you are seeing the pitfall already, good for you. The first of these two assumptions requires that people who are innocent are more responsive to control questions than they are to relevant questions. The second assumption that is made is that guilty persons will respond more intensely to relevant questions than they do to the control questions. The fact that both of these assumptions are not necessarily true can be easily challenged.

By the time I end this series on lie detector tests, you will probably know more than you ever wanted to know about polygraph tests.

Whatever you do - stay safe!