How to Beat a Lie Detector
a/k/a Polygraph Countermeasures

Cheating a lie detector test, or using polygraph Countermeasures (CM), requires a fundamental understanding of the polygraph process, physiology, psychology, and test scoring protocols.  In the instructions that follow, this information will be provided first, followed by a number of methods commonly attempted by individuals trying to get away with lying on a polygraph.

PART ONE: WHAT DOES A LIE DETECTOR MEASURE?

The word “poly” in polygraph comes from its origin “many writings.” In other words, the polygraph instrument records several different aspects of person’s physiology.

  • Breathing – Rate and volume of breaths are measured and recorded
  • Electrodermal response – Skin conductivity is measured and recorded
  • Cardiograph – Blood pressure and pulse changes are measured and recorded
  • Motion – Movements of the body (intentional and unintentional) are measured and recorded
  • Blood volume (optional) – Shifting of blood to and from inner organs

PART TWO: WHY DOES A LIE DETECTOR MEASURE THE THINGS IT DOES?

In most cases, a person lies to protect themselves from an unfavorable consequence. Humans have evolved with a very helpful, and predictable, mechanism of self-defense. The human Sympathetic Nervous System (SNS) is constantly adjusting the body to its environment. For example, we sweat when it’s hot, shiver when it’s cold, and have a faster pulse when we exercise. When we are threatened or put in danger, our bodies anticipate the need for certain systems to be on alert and to prepare us to take action to protect ourselves. These bodily changes are manifested in one or more of the following ways, which are normal responses to a threatening stimulus.

  • Blood pressure rises, anticipating the need for a physical response
  • Pulse beat changes (sometimes faster, sometimes slower)
  • Skin conductivity increases, anticipating the need for a physical response
  • Breathing rate and volume changes, to allow for more acute focus on the threat
  • Blood volume shifts toward primary organs, to better protect them

All of these elements are measured and recorded in real time while a carefully constructed series of questions is asked. These questions must be reviewed with the person being tested so that there are no surprises, and any definitions can be agreed upon.

PART THREE: HOW IS A LIE DETECTOR TEST SCORED?

During an exam, many different kinds of questions are asked, each requiring a “yes” or “no” answer. The body’s orienting response will cause a SNS reaction to every question on the exam. However, each question will have a different level of response. The examiner is measuring the relative difference between the reactions of different types of questions in the exam. If a person is lying, their bodies will generally produce a stronger SNS response to the primary questions than to the others. It is this RATIO of SNS reactions between various questions on the exam that is scored by the examiner.

IN ORDER TO BEAT A LIE DETECTOR, THE PERSON BEING TESTED MUST ALTER THEIR SNS REACTION RATIOS SO THAT THE RELATIVE DIFFERENCES BETWEEN ALL THE QUESTIONS IS MINIMIZED OR ELIMINATED.

There are many challenges to face. For any CM method to be effective, the person tested must accomplish two things simultaneously.  This is the first and biggest challenge.

  1. Reduce the SNS reactions to the primary questions.
  2. Increase the SNS reactions to the non-primary questions.

The second challenge is timing. SNS reactions occur at predictable locations within each question, although the exact location varies by individual. If the reaction occurs too early or too late, the examiner will disregard it.

The third challenge is intensity. If the SNS reactions you create are too weak, they won’t make a difference. If they are too strong, they will appear artificial and the examiner will know you are trying to beat the test.

The fourth challenge is to maintain the chosen methods throughout a series of three to five rounds of questions. Habituation makes these methods less effective over time, so while they may work well at first, they may no longer be effective by the end of the procedure.  Each test question is usually repeated several times.  The relevant questions may be presented as many as 12 to 20 times through the process.

PART FOUR: COMMON METHODS USED TO CHANGE SNS REACTIONS

There are three common methods used for attempting to alter polygraph results

  • Physical
  • Mental
  • Pharmacological

1. Physical Countermeasures

These methods require a person to artificially make changes in the measured parameters. Keep in mind that these techniques must be used without triggering the motion sensors monitored by the examiner.  Those most common methods include:

a. Clenching muscles – Regardless of which muscle is clenched, this activity will artificially increase blood pressure. Note that the examiner will be monitoring movements. Too great a change in blood pressure will be suspicious.

b. Causing pain – The SNS pain response will increase skin conductivity. This method is problematic because it is difficult to cause pain (ie. biting the tongue) without the examiner noticing, and the pain response will diminish significantly over the course of 20 or 30 questions. Also, it is quite easy for an examiner to differentiate between a pain response (sharp spike) and a self-defense response (gradual increase).

c. Shifting weight – Shifting pressure from one foot to another, or one leg to another, can cause some minor SNS reactions, but these are more easily spotted with a motion sensor.

d. Change breathing – However you normally breathe on the primary questions, breathe a little differently on the non-primary questions (faster, slower, deeper, shallower, etc.). However, avoid deep breaths, as these cause rapid physiological changes that the examiner will consider distortions, and those data can not be used.

e. Primary Questions – Since the SNS reactions to the primary questions can not be significantly reduced, just try to relax when these are asked. Remember it is the ratio between these and the other questions that is important.

f. Interference – If the process of attempting countermeasures is too daunting, then the best option may be to interfere with the exam enough that the result is inconclusive.  This is easily done with erratic body movements, taking deep breaths when answering questions, and other random variations.  The test will be ruled inconclusive, but at least it isn’t a failed exam.  The examiner may note “willful interference,” but if not failing an exam is the goal, this is one possible solution.

2. Mental Countermeasures

These methods require a person to think certain stimulating or intense thoughts during non-relevant questions in order to increase the SNS responses to those questions. These thoughts may also require mental calculations, such as mathematics or attempts to retrieve old memories. On the Primary questions, the person should think calm thoughts.  The issue with this method is that their effectiveness drops off rapidly after the first few questions, and may not have the desired effect in the end.

3. Pharmacological Countermeasures

The use of certain drugs and pain medications can reduce the overall SNS footprint throughout the exam. However, these medications will affect ALL the questions on the exam, not just the primary questions. In other words, the ratios of SNS responses will actually remain the same. This method has been found to be the least effective of all the options.

PART FIVE: TEST PREPARATION

To effectively attempt any of the methods noted, the person being tested needs to be alert and mentally prepared to execute the chosen method or methods. That means getting a good night’s rest, a decent meal, and avoiding drugs and alcohol on exam day.

PART SIX: THE INTERVIEW

To avoid appearing sanctimonious, it often helps to make small admissions to misconduct during the pre-test interview. Avoid significant admissions to any subject, if possible. If the test is failed, it is helpful to make additional small admissions to explain the failure. Serious admissions – those with serious consequences – should be avoided at all times.  The test may be failed, but the actual reason for that failure may not be clear to the examiner, unless you admit to the accusation.

PART SEVEN: COUNTERMEASURES RESEARCH

When a polygraph is complete, the examiner must “score” all the reactions on the test. It is these scores that determines the final outcome. Research has found that, for most people, attempting countermeasures actually makes their test scores worse than if they had done nothing at all. That means the only effective way to employ countermeasures is to work with an actual examiner for days or weeks ahead of time to acclimate to the process, and test out any planned CM methods. Note that most examiners will not take part in this practice, and GPN does not offer this service.  One examiner recently received jail time for coaching someone how to beat a polygraph.

CONCLUSION

Attempting polygraph countermeasures can be done effectively with a great deal of focus, awareness, and practice, but can readily backfire on someone who does not employ them correctly. If the person is not prepared to take the risk, honesty is the next best solution.

People may be curious about why a polygraph service would offer advice about beating a lie detector.  If you consider the facts that most people who attempt countermeasures actually make their scores worse, and that examiners now receive extensive training to detect countermeasures, it is actually helpful to examiners to observe these attempts in action.  In short, trying to beat the test actually makes the examiner’s job easier.

MYTHBUSTERS EXPERIMENT

On the TV show Mythbusters, GPN owner Michael Martin was asked to participate in an experiment in which three individuals would be tested regarding a “mock” crime in order to test the effectiveness of different countermeasures methods.  Spoiler alert – None of the methods were successful.  Here is a LINK TO THE VIDEO.

This page addresses the following:

  • How to beat a lie detector
  • How to beat a polygraph
  • How to cheat a lie detector
  • How to cheat a polygraph
  • Best ways to beat a lie detector
  • Best ways to beat a polygraph
  • How to lie on a lie detector
  • How to lie on a polygraph
  • Lie Detector Countermeasures
  • Polygraph Countermeasures
  • How to pass a lie detector test
  • How to pass a polygraph test

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