How to Beat a Polygraph Test

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A complete guide to keeping your cool and passing a polygraph exam
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The infamous polygraph test—also known as the "lie detector" test—is often looked upon as cause for anxiety and fear, even among people who are perfectly innocent and who should be able to pass the test without cheating or manipulating the results. If you need advice on how to pass a polygraph test one way or another, you've come to the right place.

How to Pass a Lie Detector Test

  1. Bite your tongue or hold your breath during control questions.
  2. Imagine a peaceful setting to stay calm during relevant questions.
  3. Answer only with “yes” or “no”—avoid any elaboration or explanation.
  4. Respond truthfully if you have nothing to hide.
Section 1 of 5:

11 Ways to Pass a Polygraph Test

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  1. 1
    Stay completely zen OR completely distraught the entire test. The best way to beat a lie detector test is to stay completely calm throughout the entire exam, no matter what you’re asked. Since it’s difficult for most people to completely control their physiology, it may be better to swing to the other end of the spectrum and act upset for the whole test.
    • Think through the worst experience of your life, recall a tear-jerking film scene, or try to do long division in your head.
    • If there’s a certain question you’re really anxious about, imagine every question is that question before answering. That alone may be enough to keep your heart rate up.
    • Whatever keeps you in a constant state of excitation, stress, or fear—do that!
  2. 2
    Stress yourself out when answering the pre-interview questions. If you feel the need to cheat or manipulate the test, try to cause yourself mental or physical stress when giving answers to the control questions. This section often includes harmless questions that the tester assumes you’ll lie about—such as “Have you ever stolen money?,” “Have you ever lied to your parents?,” or “Have you ever cheated on a test?” [1]
    • Most people have done these things once but still lie about it on the polygraph test. For this reason, the examiner uses your response to these questions as a way to establish how you physically react when lying.
    • When answering these questions, do something to raise your heart rate and perspiration: think of a frightening or exciting thought, gently bite your tongue, or try to solve a difficult math problem in your head. [2]
    • Another strategy is to tense your muscles or alter your breathing rate during these questions (and return to normal for the rest of the test). For example, you could quicken your breath, breathe more shallowly, or hold your breath as long as possible.
    • As a result, your baseline will be higher so any subsequent spikes during important lies will seem minor and may remain undetected.
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  3. When asked a question relevant to the case or situation, put yourself in a calm state of mind when you answer. By staying as calm as possible, you can prevent many major spikes in your physiological responses (especially if you’re actually lying). [3]
    • Maintain your breathing pattern and keep in mind that the polygraph is not infallible, and that you are in control of your own physiological response.
    • Daydream about something soothing like cuddling under a warm blanket with a cup of hot chocolate on a cool night or taking a relaxing shower or bath.
    • Essentially, a “lie” only counts if that lie generates a greater physiological response than that which you had while you were telling “white lies” with the control questions. [4]
    • As long as your physiological response to a question and answer produces a less noticeable reaction than any reaction you displayed while answering the control questions, it will probably not count against you.
  4. 4
    Identify the purpose of each question before answering. Determine if question is irrelevant (e.g., “What is your full name?”), relevant (e.g., “Did you know about the crime?”, or used for diagnostic/control purposes (e.g., “Have you ever lied to get out of trouble?”). [5] Take your time and ask clarifying questions as needed—depending on the examiner, you can ask for a question to be repeated between 2-6 times.
    • Do not rush through the questions, since this sense of haste can skew the results against you.
    • You can also review the questions before the test—in most cases, the polygraph examiner is required to tell you the questions ahead of time.
    • Take all the time you need reviewing them, and feel free to ask the examiner for clarification about uncertain or confusing questions.
  5. 5
    Mentally change the meaning of the questions being asked. Take the question that’s been asked and manipulate it in your head to mean something else. If you do this successfully, you’ll be able to answer the question without feeling guilty or having the physiological response associated with a lie.
    • For example, maybe you’ve been asked “Were you at the park between 6 and 7pm?”
    • If you need your response to be a lie, take a moment to convince yourself that the examiner has asked “Were you at the zoo between 6 and 7pm?” or “Were you at the park between noon and 1pm?”
    • If you offer a lie as your answer, your mind won’t feel like it’s really lying.
  6. 6
    Answer firmly and concisely with “yes” or “no.” Most questions asked during your polygraph will only require a yes-or-no answer. [6] Avoid offering any explanations or elaborations unless absolutely necessary.
    • If you do have to respond with more than a yes-or-no answer, give a strange or vague response that makes it difficult for the examiner to pin down what your “normal” response would be.
    • If you say “yes” or “no” and the administrator asks you to expand on your answer, reply with “What more do you want me to say?” or “There’s really nothing more to say about that.”
    • Be cooperative and reply without any coldness or edge to your voice. However, avoid being overly congenial or humorous in your answers.
  7. 7
    Resist responding to accusations of dishonesty. An examiner may accuse you of lying or note that they have detected a lie. Don’t admit to having lied—if anything, channel the accusation into your feelings of being upset and confused so that the examiner continues to have conflicting results.
  8. 8
    Speak truthfully. If you have nothing to hide or be ashamed of, then tell the truth to each question you are asked. This includes control questions, for which many people are expected to lie. The more often you tell the truth, the more accurate the results will be. This is a good thing, as long as you are innocent. [7]
    • While people often believe that there will be "trick" questions designed to trap them into a guilty answer, the current state of ethics surrounding the administration of polygraph exams demands that the questions remain straightforward. No surprise questions will be asked, either.
    • Listen to the entire question thoroughly and answer it precisely. Do not listen to only half the question or answer the question according to what you think it asked rather than what it actually asked.
  9. 9
    Let yourself be nervous. Nowadays, no one is expected to remain perfectly calm during a polygraph test, even if the person in question is perfectly innocent and has nothing to hide. [8]
    • By allowing yourself to be nervous, you can provide the polygraph examiner with an accurate representation of your physiological statistics when you are being truthful and when you are lying.
    • The lines on the polygraph screen will never be flat and smooth, even if you are telling the truth.
    • Oddly enough, only the person who is nervous about every answer will appear the most truthful on a polygraph test.
  10. 10
    Avoid tricks that are easy to catch. If the examiner catches you trying to cheat the test, you might be asked to schedule another test or the examiner may take countermeasures against further acts of manipulation. Moreover, attempts to manipulate the test might cause the examiner or reviewer to judge your results more harshly once you finish.
    • For instance, some sources recommend that you stick a thumbtack in your shoe and attempt to press down on it to spike your vitals during control questions.
    • Oftentimes, an examiner will have you remove your shoes during the test to avoid such tricks. [9]
    • In fact, while physical pain will cause your vitals to spike, it is usually easier to catch than psychological stress.
    • Biting your tongue, clenching a muscle, or other similar tactics can be caught easily if you are working with a trained polygraph professional.
  11. 11
    Practice countermeasures before the lie detector test. Ask a trusted friend or confidante to ask you questions that you’re likely to be asked during the exam. Take note of your heart rate and breathing and how they change in response to different types of questions.
    • However, try not to overthink the test too much beforehand—you might run the risk of skewing the test against your favor by working yourself up over your responses. [10]
    • Avoid spending too much time reviewing anti-polygraph websites, since these websites often mix fact with hyped-up conspiracies and may cause undue panic.
    • Instead, get plenty of rest the night before the test—aim for 7-8 hours. Follow your typical nighttime and morning routine, eat a complete meal, and wear comfortable clothing for the exam.
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Section 2 of 5:

How a Lie Detector Test Works

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  1. 1
    Polygraphs track physiological changes in your body. A polygraph exam doesn’t technically detect lies, but it will detect shifts in your blood pressure, pulse, respiration, and perspiration, all of which are associated with deception. [11]
    • When you take a lie detector test, the exam administrator should explain to you how all of the mechanics work. If they don’t, feel free to ask questions.
    • They may also give you certain forms to grant your authorization. Take your time reading those forms and make sure you understand exactly how the test works before signing.
  2. 2
    Different polygraph tests use different formats and question types. The standard polygraph test is the CQT, or "Control Question Test." In some instances, however, you may be given a "Directed Lie Test" (DLT) or "Guilty Knowledge Test" (GKT) instead. [12] Learning the type of lie detector test you’ll undergo may help you prepare to pass the exam.
    • With a CQT polygraph , control questions will be mixed in among the relevant questions. A control question is one that nearly everyone will need to reply "yes" to, even though many people will be tempted to reply "no." Such questions include ones like, "Have you ever told a lie to your parents?" or "Have you ever stolen or borrowed something without permission?"
    • With a DLT , you will be asked several questions by the examiner and directly asked to lie about those questions. In doing so, the examiner can gauge your physiological responses to lying by reviewing the questions he or she knew you lied on.
    • For a GKT , you will be asked multiple choice questions about various facts that only you and the examiner would know. Many of these questions will be about the case. Your verbal responses will be compared to your physiological responses.
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Section 3 of 5:

Is a polygraph exam accurate?

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  1. Most research suggests that polygraphs are largely inaccurate. While lie detectors can sometimes be accurate, many believe that polygraphs are a form of pseudoscience. [13] The accuracy of their results largely depends on the context they’re used in.
    • For example, polygraph tests may appear to be accurate if the person is conditioned to fear the exam. Therefore, the individual will become very nervous, indicating a “lie.”
    • While this may be the “correct” result, the test is really detecting fear—not lies. [14]
    • However, many people produce false positives and are shown to be lying when they’re not. This phenomenon likely results from the natural nervousness most people feel when entering a high-pressure situation, even when they have nothing to hide. [15]
    • Overall, polygraph evidence still doesn’t have enough evidence backing it to be used in criminal courts throughout the U.S. and most of Europe. [16]
Section 4 of 5:

Is it possible to beat a polygraph test?

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  1. Yes, it is possible to beat a polygraph test. Ultimately, polygraphs measure bodily responses, not actual lies. As long as someone can reasonably manipulate their physiological responses, they can beat a polygraph test. [17]
    • However, the strategies to beat a lie detector test may not work for every individual. Their efficacy may depend on the type of test and the experience of the examiner.
    • Plus, most polygraph administrators know the common countermeasures and are able to spot them, so attempting to beat the test isn’t always successful.
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Section 5 of 5:

Techniques Used to Detect Cheating

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  1. Polygraph administrators may observe your physical behavior, eye movement, and other factors to determine if you’re lying. Aside from the test itself, professional examiners learn the common tricks that people use to try to beat the test and get away with lying. Some of the techniques they use to pick up on deception include: [18]
    • Behavioral observation: Examiners watch for changes in posture, fidgeting, or marked changes in breathing.
    • Eye-tracking: Eye-tracking technology can determine if you’re trying to mask your emotions by avoiding eye contact.
    • Voice stress analysis: This type of analysis is used to measure the frequency and amplitude of your voice in ways that might reveal deceit.
    • Psychological evaluation: Administrators may evaluate your psychological state, including any level of anxiety or stress.
    • Follow-up questions & interviews: If any part of the test seems suspicious or is deemed inconclusive, the examiner might ask you follow-up questions or schedule a follow-up interview.

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  • Question
    Can an employee refuse a polygraph test?
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    Staff Answer
    This answer was written by one of our trained team of researchers who validated it for accuracy and comprehensiveness.
    wikiHow Staff Editor
    Staff Answer
    Absolutely yes, and an employer cannot require, request or even suggest a lie detector test be taken by an employee or job applicant. As an employer you also cannot discipline, dismiss, discriminate against or threaten to take action against any employee or job applicant who refuses a test. There are a few exceptions to these laws, for certain government employees and for jobs related to security, handling drugs or when investigating a specific theft or suspected crime. Even if a test is potentially allowed, there must be a reasonable and provable suspicion that the person was involved, at least 48 hours of notice before the test, as well as specific limitations on how the test can be given.
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    How accurate is the lie detector test?
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    This answer was written by one of our trained team of researchers who validated it for accuracy and comprehensiveness.
    wikiHow Staff Editor
    Staff Answer
    Lie detector tests are notoriously inaccurate. There is no good, reliable or evidence-based way to connect the kind of data that lie detector tests measure (such as readings on skin conductivity, blood pressure, heart rate and breathing) with whether or not someone is telling the truth. The American Psychological Association says that, "...the most practical advice is to remain skeptical about any conclusion wrung from a polygraph."
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    Can you fail a polygraph by being nervous?
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    This answer was written by one of our trained team of researchers who validated it for accuracy and comprehensiveness.
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    This is certainly a possibility and one of many reasons why polygraphs are unlikely to be very accurate.
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      Tips

      • Let your examiner know before the test if you have any mental or physical health conditions, take medications, or are otherwise feeling ill.
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      • Once you’ve completed the lie detector test, wait for your official results and any follow-up testing. If you don’t receive the results within 1-2 weeks, call or contact your examiner to request them.
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      • Some medical conditions prohibit the use of lie detector tests. People who have epilepsy, nerve damage, heart disease, stroke history, or extreme fatigue shouldn’t take the test. Pregnant women and people diagnosed with antisocial personality disorder or psychopathy are also generally exempted from the test.
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      Tips from our Readers

      The advice in this section is based on the lived experiences of wikiHow readers like you. If you have a helpful tip you’d like to share on wikiHow, please submit it in the field below.
      • If the blood pressure cuff becomes too uncomfortable for you, tell the examiner. My examiner was very considerate and paused the test so she could release the air in the cuff.
      • To make the polygraph "spike," clench the muscles in your butt. This action can't be seen, but it will cause a spike in your blood pressure.
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      Warnings

      • Avoid resorting to manipulation. If you are innocent and have nothing to hide, your best bet is simply to be honest and truthful during the test.
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      • Some people may advise the use of certain drugs that can alter the result of a polygraph test, such as heart rate and blood pressure medication. However, the use of drugs for this purpose should be avoided because of potential health risks. Plus, most lie detector tests are preceded by a drug test anyways.
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      References

      1. ↑ https://www.iflscience.com/how-to-beat-a-lie-detector-69212
      2. ↑ https://www.livescience.com/33512-pass-lie-detector-polygraph.html
      3. ↑ https://www.livescience.com/33512-pass-lie-detector-polygraph.html
      4. ↑ https://www.livescience.com/33512-pass-lie-detector-polygraph.html
      5. ↑ https://www.bbc.com/future/article/20160412-can-you-beat-a-lie-detector-test
      6. ↑ https://nap.nationalacademies.org/read/10420/chapter/3#12
      7. ↑ https://iamscpd.org/polygraph-psych-medical
      8. ↑ https://iamscpd.org/polygraph-psych-medical
      9. ↑ https://www.livescience.com/33512-pass-lie-detector-polygraph.html
      1. ↑ https://www.military.com/veteran-jobs/security-clearance-jobs/passing-polygraph.html
      2. ↑ https://www.livescience.com/33512-pass-lie-detector-polygraph.html
      3. ↑ https://nap.nationalacademies.org/read/10420/chapter/3#14
      4. ↑ https://link.springer.com/article/10.1007/BF02912514
      5. ↑ https://www.apa.org/topics/cognitive-neuroscience/polygraph
      6. ↑ https://insidetime.org/wp-content/uploads/2021/12/Polygraph-scientific-paper-RPS-2004.pdf
      7. ↑ https://scholar.google.com/scholar_case?case=13874937043928283511&hl=en&as_sdt=6&as_vis=1&oi=scholarr
      8. ↑ https://www.apa.org/topics/cognitive-neuroscience/polygraph
      9. ↑ https://liedetectortest.com/polygraph/what-behavior-does-a-polygraph-examiner-look-for-in-a-lie-detector-test

      About This Article

      Article Summary X

      If you need to manipulate a polygraph test, stress yourself out when answering control questions to give yourself a higher baseline. You can do this by thinking about something scary or exciting or trying to solve a hard problem in your head while responding to the questions. Additionally, you’ll want to stay as calm as possible when answering relevant questions by daydreaming or breathing in an even, controlled way. Finally, avoid using techniques that are easily caught, like tensing muscles, biting your tongue, or pinching yourself. To learn how a polygraph tests works, including what types of questions you can anticipate, keep reading!

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