How To Cheat a Polygraph Test (Lie Detector)

There are a variety of instances in which you may be subjected to a polygraph, or lie detector examination. These tests can be a source of tremendous anxiety, especially since it is all too common for innocent people to fail them for no reason, resulting in the denial of employment or false criminal accusations. Why? Because polygraphs are far from perfect. In fact, many experts consider them a farce, and almost all scientists who have studied them (and even some polygraph administrators) understand that polygraphs are seriously limited. Fortunately, for this very reason they are easy to trick. So whether you don’t want your potential employer to know about your youthful mistakes or you want to make sure you don’t fail a polygraph just because you’re nervous, follow these steps to take control of your interrogation.

Step 1  

Refuse a polygraph test if you can. For pre-employment screenings this will almost certainly ensure that you don’t get hired, but it probably will not get you fired in most circumstances. In the USA, private sector employers may not terminate employment or take other such adverse actions based solely on a polygraph refusal (this protection usually does not cover government employees). If, in advance you are thinking about what confessions they are looking for, what things you cannot admit. The polygrapher will ask you many uncomfortable questions, but only certain ones are important. If your test is prompted by a specific incident, you probably know what the examiner is looking for, but for pre-employment screening tests and the like, research the company or agency’s policies to determine what you can and cannot admit.

Step 2  

Approach your whole "polygraph day" as a test. Treat the polygraph examination as an S.A.T.

Step 3  

Identify the types of questions you are being asked. There are three basic types of question is a complex ruse to trick you into confessing something. Never do any research on polygraph tests or what you know about them. Do not disclose that you’ve done extensive research, and act as though you don’t know much about polygraph examinations but that you do believe polygraphy to be a science and polygraphs to be reliable (or at least do not exhibit any doubt as to their reliability). The polygrapher may try to trick you by mentioning certain technical terms and acronyms, such as, "Your test came back NDI." While you know (or will now know) that "NDI" means "no deception indicated," you need to act as though you have no idea what it means. Too much knowledge of the process may make the polygrapher think you’ve got something to hide, even if you don’t.

Step 4  

Throw off the machine's reading of the control questions by changing your blood pressure and heart rate. It’s difficult to do, but with practice, the next few methods and countermeasures will prompt your body to do so. Do some of the following when replying to control questions:  

• Develop a breathing strategy. Throughout the test (except during control questions) maintain a normal breathing rate of 15-30 breaths per minute. Do not breathe too deeply. Then alter breathing rate with control questions. You can make it faster or slower, you can hold your breath for a couple of seconds after an exhalation, or you can breathe more shallowly, for example. Do this for 5-15 seconds, and return to your normal breathing pattern before the next question. As explained above, the polygrapher will compare your physiological responses to control questions to your responses to relevant questions. If the deviation from normal during control questions exceeds the deviation from normal during relevant questions, you will pass. If, however, you react more to a relevant question than to control questions, the polygrapher will perceive (rightly or wrongly) that you are lying in response to something relevant—you will fail the polygraph.
• Do math in your head. During control questions, do something mentally complex. For example, count backwards in your head as quickly as possible or do some quick long division, as you are answering the question.
• Think about something exciting or frightening; think of things that make you ecstatic, fearful, or frustrated.
• Bite your tongue. Bite the side of your tongue hard enough to cause pain, but not so hard as to draw blood. Practice this in a mirror to be sure the polygrapher cannot detect it. This is highly effective, but may be detectable if you have to speak for an extended period, because you can’t bite while you’re speaking. Only use this method if you can give a quick "yes" or "no" response, which, luckily, will be most of the time.
• Insert a small nail or tack in the toe area of your shoe and press down on this during the control questions to elicit a pain response. This is a sound method, but it is easily defeated if the polygrapher asks you to remove your shoes.
• Contract your anal sphincter muscle when a control question is asked. While also highly effective, this method may (or may not) be discovered with the use of pressure-sensitive seat pads that are now commonly used.

Step 5  

Handle the post-test interview. After you’re disconnected from the machine, the polygrapher may leave you in the room for a while and come back. The polygrapher may then claim to "know" that you are lying about something. This is a trick. Remain calm, firmly, but politely repeat your denial, and don’t change or argue your answers, even in the slightest way. Decline extended post-test interviewing if possible.

The Questioning Procedures

1. First, you are "put at ease" by the administrator, and he or she talks to you about all the questions you already answered on a questionnaire or in the pre-interview. They put you at ease and tell you that it is completely normal (because it is) for some things to “suddenly” pop in your head about things you might have forgotten to mention in the pre-questionnaire/interview. They explain that they are going to ask you many of the same questions again, without the polygraph, to catch these sudden recollections. Again, they explain this is normal (again, because it is). They ask you the same questions that were in the pre-interview, and almost always, you will recall things you forgot to mention. They tell you this does not hurt you, and so all things should come out now. As you go through the questions again, they probe deeper until you are sure you have revealed everything you are asked about that particular question (employee theft, for example). After you confess a few more instances of employee theft, they take that in stride. They do use this step in the process to get more heinous info from you, but typically, are just trying to get your mind clear of any small things you might be hiding. They are not typically interested in the small stuff, and accept that you are just now recalling it.
2. After they complete that step, they then move to a simpler test of fewer, more general questions, such as “Is there anything else you wish to discuss before we begin the test?” and “Is there anything you have not revealed that I have asked of you?” They are getting the slate clean of any extra issues.
3. They then explain how the polygraph works. They tell you the truth, that it does not detect lying, and is not admissible in court. They explain all the following before hooking you up, and do not hold back anything. They explain that it is not magic, and that it simply tracks physiological responses you might give after being asked a question. They explain to you that the questions are all "yes" and "no", and no explanations are requested. They explain that they will ask you all the questions that are on the test before hand, so you know what you will be asked. They explain they also will ask them to you in the same order before hand as they will during the test. They explain that they do this on purpose, to better catch a physiological response. They are clear that "surprise" questions are not asked, nor would the physiological response from a surprise question be worthy. They explain that you will be aware what question will be asked and when before the test. They then explain that this is so you will know when the "troublesome" question, if there is one, is coming up. They explain that is what the polygraph measures. You will be asked baseline questions at the beginning, things you and the administrator already know, such as your name, date of birth, and maybe one or two more simple questions. They explain that the polygraph baseline will show a normal rise as you listen to the question, then fall after you answer it. They explain that as they progress though the other questions, since you know about where the "troublesome" question is, your baseline will start to rise slowly after each question is asked before it. You will not have to remember exactly where the question is, just that it has not been asked yet. They then explain that your baseline gets higher and higher until the troublesome question, if there is one, is asked... when they ask it, that is the key thing the polygraph records.. the more dramatic drop in the baseline.. i.e., the "relief". The polygraph depends on the normal human psychology of anticipation and release of tension once the anticipated event passes (sociopaths, for example, typically do not show this anticipation and release, where as most people do). Again, the administrator explains ALL of this before ever hooking you up, and explains it on purpose. They want you to know exactly what the polygraph records, because that knowledge makes you more susceptible to showing a "release" after a troublesome question.

Tips

• Practice countermeasures in advance. The countermeasures listed here can almost guarantee that you “pass” the polygraph examination, but only if you do them right. Once you read about the measures, be sure to practice them well before the test so that you’re thoroughly prepared.
• The needles on the machine chart physiological changes, such as breathing and heart rate, over time. While this sort of machine is still frequently used, computer-based polygraph machines are becoming more common. Don't let either of them intimidate you.
• Remember that you are being watched closely during the test. When you use countermeasures, use them discreetly. You want your actions to appear subtle and unconscious.
• There are several subtle variations on the polygraph test. Be sure to research these thoroughly before your test to be prepared for anything they might throw at you.
• If you do not feel comfortable employing countermeasures from a moral standpoint, you are probably better off not taking the test. Even if this means, for example, that you will not get a job. In almost all circumstances, "passing" a polygraph cannot help you get a job, nor can it exonerate you from an alleged crime. A "failed" polygraph, however, can serve to bar you from employment or cast suspicion upon you. Still, a polygraph test is not accurate all of the time, for every person.
• Understand that polygraphs do not detect lying. They detect physiological responses when you are tha polygraph works, when administered correctly. Many times, polygraphs are not administered correctly (usually by private firms hired by employers). However, in law enforcement for major cities, the polygraph is typically administered correctly. The correct way is as follows:
• So, if you were to hook up a polygraph to yourself in your basement and have your buddy ask you questions, it would likely not show any such anticipation/relief responses. However, the nervousness in employment interviews and police questioning is your give away. You are expected to be nervous and that is accounted for. The polygraph takes your baseline, which is your base physiological response when you are nervous. Even if you were not nervous, the baseline measures that as well. It matters not where the baseline is on the graph. What matters, is how that base line changes as the questions are asked. So, even if you are nervous as a rabbit with the baseline, you still will likely show an anticipation/relief response when asked a question you have lied about, or are holding back information about. Also, erratic changes in the baseline show a purposeful attempt to thwart it, such as trying to control your breathing, or constricting the anus.
• Remember that the Polygraph is nothing more than a complex trick to get you to make an admission. Never make a relevant admission! The polygrapher only knows what you tell them and nothing more. Many honest people fail the polygraph, and they will take this into consideration. But make an admission, and you will not pass.
• Think to yourself that the answer you are giving is the truth this will calm down anything the the polygraph will detect as a lie.
• Do not rely on the truth to prevent positive indications. The most important factor is your state of mind. You need to be relaxed. You need to know they cannot read your mind. And even if they could, they are your adversary. You need to manage your own mental state. Relax.

Warnings

• Remember that the polygrapher is not your friend, if you are trying to hold back information. The polygrapher may try to convince you that they are on your side and will help you out if you’ll just be truthful. This is deception; don’t buy it. However, a more professional polygraph administrator will not pretend to be your friend, and will tell you up front that they are simply attempting to discover if you are holding back information.
• Beware pretest tricks. Polygraphers will frequently attempt to instill fear in the subject or convince the subject of the accuracy of the polygraph machine. The theory is that the more you fear that you may be caught the greater your physiological reactions will be. Don’t believe the hype. In addition, the polygrapher may try to elicit telling reactions from you based on fear. For example, he or she may say that you need to wash your hands so the machine can accurately read your sweat output. A hidden camera in the bathroom may then catch you going into the bathroom as directed, but not washing your hands.
• Perform only one heart rate/blood pressure altering countermeasure at a time or it may become too obvious.
• These steps are good, but not foolproof.