Q&A for How to Cheat a Polygraph Test (Lie Detector)

Nope! In fact, investigators rarely use them. When they do try to get a suspect to take a polygraph, it's more for show as a scare tactic than because they care about the results.

Yes, it is possible to lie and pass a polygraph. First, the machine itself has flaws which can be exploited and many consider these devices to be, at best, "pseudoscience"; it’s best to do some reading on this aspect, as the discussion is lengthy. Second, you can try gaming the test questions at the start by lying when answering these "probable-lie" set-up questions and biting your tongue hard at the same time, to produce physiological reactions that seem off the charts (Tice, 2012). This makes the test taker think that you have major reactions when lying (it’s actually your body going "ouch!" to the bitten tongue). Then don’t bite your tongue when actually lying on the real questions and it’ll come across as the truth. According to Tice (2012), daydreaming while answering questions can help too, as it distracts your mind from the pressure.

The more accurate question is whether a lie detector test can be trusted to be right! Polygraph testing is easily gamed by countermeasures like controlling your breathing, anxiety, using pain, etc., and even by being nice to the person doing the testing (see Wikipedia, "Polygraph"). But the most concerning issue is the lack of scientific, judicial and academic support for the lie detector test, as it is considered by many independent researchers to be a form of pseudoscience and too many intervening factors can cause it to show guilt where there is none, such as being anxious, tired, scared, afraid, emotionally aroused, misunderstanding the situation, etc. So yes, a lie detector test can be wrong, let alone the problem that it’s a coercive instrument when used in the context of the workplace, as it risks reducing trust between employer and employee.

Scientifically speaking, the results are not considered by a majority of independent researchers to be that accurate and there is a higher chance of innocent persons being found guilty and guilty persons gaming it (by using countermeasures) and being found innocent (Iacono 2001). The National Research Council has found that there is no evidence of the effectiveness of polygraphs (National Research Council, 2003). Courts do not generally trust evidence from lie detector machines to be reliable (Wikipedia, Polygraph). The very anxiety brought up by thinking someone/your employer doesn’t trust, believe or care about you can be enough to make the machine interpret this as lying, when in actual fact it’s often more about the lack of trust in you than actual dishonesty.

There are various methods you can use to try to beat a polygraph test, some of which are explained in the article above. One way to beat a polygraph test is to avoid it altogether; you could try to get help from a lawyer to argue that it’s a coercive practice with pseudo-scientific outcomes that are highly inappropriate for an employee to be forced to undertake. For more help with arguing against the validity of using polygraph tests in the workplace (or anywhere else), see the site AntiPolygraph.org, which exposes the lies around the device itself and the poor uses to which the so-called results are put.

It varies depending on what the questions are for, and what they need to know.

Yes, it will. Fatigue will stress you out and increase your blood pressure.

In some circumstances, it can. When you're pregnant, they usually will not perform these tests.

Yes, a nerve disorder may make you fail a test even if you are telling the truth. Disclose your disorder to the test giver before the exam.

Yes, especially if you get a flashback at the wrong moment, so inform the polygrapher of this.

To do so is illegal and it is easier to get caught bribing then cheating a polygraph. Thus, it is not a recommended course of action.

Focus on what your body is doing while it's doing it. Direct your attention to slowing your breathing, and keeping it steady, thus slowing your heart rate and lowering blood pressure. Remember how mentally influenced your body is. You can even slow down your heart rate simply by paying attention to what you want it to do. By directing your attention fully to the calmness of your body, and remaining confident, you should be able to successfully cheat the polygraph.

A polygraph can indicate that you're lying even if you are telling the truth, especially if the test is stressing you out. Stress and lying are associated with many of the same biological responses. For this reason, polygraph results are no longer admissible as evidence in legal trials. So, if you are found guilty despite being innocent, it won't be because of a lie detector.

This can take from 15 - 40 minutes, depending on how it's administered.

Yes. Stay as calm as possible.

Usual polygraph protocol mandates a drug/alcohol test before testing, so it's unlikely that you would ever be be given a polygraph if you are under the influence.

Yes, pain and lying cause similar results. Another way to do this is by using a thumbtack in your shoe.

Taking calming pills is akin to doping in sports. It can also have adverse side effects on your body, which could be reflected on the test. So pills are definitely not recommended.

Unfortunate, there is no definite answer for there. It will depend on the type of polygraph, when it was made, who made it, etc.

Yes, it is possible. The polygraph looks at changes in heart rate and blood pressure, so it is possible to fail if you are uncomfortable with a question.

The process for getting results can take minutes or hours, depending on the length of the test.

It shouldn't. But inform them of your illness and ongoing symptoms before you take the test, just in case.

No Benadryl is an allergy pill which will make you feel better not rig the test

All control questions. These are what they are comparing your relevant questions to. Some of the time, the tester will begin each control question with, "have you ever, in all your life..." This gives you a heads up, and you can begin your breathing alterations and whichever negative mental imagery you've decided to use. By the time he's finished asking his control question, your body should be reacting.

Yes. That's the normal way to pass a polygraph test. Cheating is for those who don't want to tell the truth.

You can only reply yes or no on a polygraph test.

No, as it will probably catch the eye of the polygrapher, thus leading him to think you're lying.

No. The test isn't admissible in court, therefore no legal action can be taken based off of the polygrapher's findings.

It may in some cases, but don't overdo it as it induces stress.

Well, no, as the administrator will establish a baseline when the test starts.