From 1996 to 2002 I was known as “The Lie Detector Guy” because I made hundreds of appearances on U.S. and International television shows as a polygraph expert. My experience working with these shows has literally given me a “back stage pass” into the inner workings of television shows and how polygraph is generally used.

The exams I conducted for these shows were absolutely real, but that didn’t stop producers from suggesting that they wanted a particular outcome of a test. I also learned a lot from producers who have told me things like “Well, so-and-so examiner told us he could do our exams for $100 each and they would only take 20 minutes.” Unfortunately, those are not real polygraphs. My average exam took about 90 minutes.

Most people obtain their polygraph “knowledge” from watching television shows… reality shows, court shows, talk shows, dramas. In most cases these exams are staged for the cameras, producers and the audience, and are NOT REAL POLYGRAPHS. Here are some things you should know about polygraphs and why they are often not reliable when done for television:

  • Polygraph exams can not be done in front of a live audience.
  • Polygraph exams must be done in a controlled environment with no distractions
  • Polygraph results can not be analyzed in real time.  The questions must be reviewed beforehand, then asked several times, then scored.  The “thumbs up” or “thumbs down” results seen on some shows are only for entertainment.  It’s not how a real exam works.  One of the more prolific TV examiners is John Grogan – read more about Grogan HERE.
  • Polygraph accuracy drops as you add more questions (there is usually a limit of 3 to 4 relevant questions permitted per exam)
  • Polygraph answers are limited to “yes” and “no” (narrative answers are not allowed)
  • Polygraph questions are spread out so that reactions have time to dissipate from the previous question (the average time between questions should be 20 to 25 seconds)
  • Movement by the examinee causes distortions with the test results (if the examinee is moving around or talking during the exam, reliable data can not be collected)
  • Polygraph exams must be done at least 3 times before a decision can be rendered (each question must be asked at least 3 separate times during the procedure)
  • Polygraph exams take 60 to 90 minutes or longer if done correctly (most TV shows will not allow that much time for an exam)
  • Polygraph questions must be objective – about facts – not about opinions or feelings
  • Surprise questions are not permitted (all questions are reviewed before the test)

Are polygraph tests on television real? Sometimes they are, but most of the time they are not.

When a highly qualified examiner conducts polygraphs for television, the exams are done off-camera before the show and can take several hours each. The examiner may then re-enact a small portion of the exam for the audience, so what you see is never an actual polygraph. Unfortunately, most so-called examiners working for television provide 20 minute exams, ask a dozen questions, and give results that are no more accurate than flipping a coin. Any producer who actually cares about the quality of the test and the results will allow the examiner to spend sufficient time with the person tested (up to several hours) and will limit the number of questions to three or less (per exam) to maintain overall accuracy. Most producers are only interested in getting a test done in the shortest amount of time and the smallest budget possible. Don’t believe everything you see on television, and don’t expect an examiner to provide a test like you see on television. That is not reality.


Fox TV’s game show “The Moment of Truth” aired in the United States in 2011-12. While this show may have been entertaining to some, the polygraph aspect of the show had no validity whatsoever.

I am publishing my opinion about this show so that potential clients do not develop unrealistic expectations of polygraph testing and what it can accomplish. Fox TV has blocked us from publishing this information on their public internet forum, so I am providing the information here.

Here is why the Moment of Truth polygraphs can not be relied upon:
Note: Definition of “Relevant Question” – The primary question on a polygraph exam that requires resolution. There are several other types of questions included in a polygraph exam, but they are processed differently than Relevant Questions.

Reason #1

Many of the relevant questions on Moment of Truth are simply opinions, not facts. Opinions can not be asked on a polygraph with any reliability. Opinions, unlike facts, all involve a small degree of uncertainty, leading to a subjective response. That uncertainty may in itself produce a significant level of false-deceptive results. If a person feels that they have, now or in the past, ever doubted the truthfulness of their answer, it will likely cause a false-deceptive reaction on the polygraph. Any results from these questions can not be relied upon.

Reason #2

Many of the relevant questions on Moment of Truth are about what the contestant thinks will happen in the future. If we had the technology to tell what someone was going to do in the future, there would be very little crime. These questions, like the “opinion” questions discussed above, involve a degree of uncertainty that will render any polygraph conclusion useless.

Reason #3

A properly-conducted polygraph has a very narrow focus, and typically includes only one or two relevant questions. The show’s web site indicates that 50 to 75 relevant polygraph questions are asked during the exam, and then they cull them down to the 21 questions they decide to use on the show. Polygraph research gives us a 90 to 95% degree of accuracy in a single-issue exam, which can take several hours to complete. If done to current industry standards (using one relevant question per test) it would take weeks of testing to cover as many relevant questions as the show is claiming to do.

It is generally accepted in the polygraph community that polygraph results become less accurate as you add more (and varied) questions. Since no research has been done to support a multiple-question exam, there is no scientific data to empirically support the results of a multiple-question test.

Next, we have the process of TCM, or total chart minutes, which states in part that a person’s physiological reactions on a polygraph will be reduced over time to a point where the data collected is no longer useful. In other words, as you ask more questions, you get less reactions. The person being tested must exhibit some level of reaction in order to have those reactions analyzed, so if the reactions no longer exist because the person has been tested too long, the test is worthless and no conclusions can be drawn at all. This typically begins to happen after about 30 minutes of continuous testing. For this reason, a qualified examiner will not usually conduct more than 3 separate exams on a person in the same day. It should also be noted that to render a conclusion, the examinee should be asked all the test questions at least three times, so on a typical polygraph all the questions are asked 3 to 5 times with a small break between each question series.

The only way to ask a large number of relevant questions on a polygraph is to ask them all on the same test and compare them to one another. This is called a peak of tension test, and all this test does is isolate the relevant questions that cause greater concern than the others. This test is used for screening only. This test format will NOT determine truth or deception.

If the show wants to conduct accurate exams, they would first have to change the relevant questions to cover fact-based topics only (about events that did or did not take place in the past) and then they would have to set aside one full day for each 3 questions to be asked. That would require over two weeks of testing to cover just 50 questions accurately.

The basis for my opinions can be verified by contacting any accredited polygraph training school.

Due to the vague, subjective, futuristic nature, and sheer volume, of relevant questions asked on The Moment of Truth, there can be little more than chance accuracy in determining truth or deception to these questions. In other words, they could simply flip a coin and achieve the same accuracy levels.

Do not expect a qualified examiner to do what the Moment of Truth TV show does.

Questions? Contact to Michael Martin at


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