How to Beat a Polygraph (Lie Detector)?

The lie detector, also known as a polygraph, is used not only in criminal investigations to determine a suspect’s guilt (if you’re in deep trouble, study this guide carefully and demand a polygraph test—it might be your last chance at freedom), but also by some companies during job interviews. With a claimed accuracy of 90-95%, HR departments use polygraphs to assess whether a potential employee might, for example, commit theft. However, we believe that using a polygraph is degrading and encourage everyone to pass the test successfully and outsmart the lie detector whenever possible.

Part 1: Understanding the Polygraph Test

Let’s address the main question: if it’s so easy to beat a lie detector, why is it still widely used? The truth is, passing a polygraph by lying without triggering changes in blood pressure, breathing, pulse, and other physiological indicators (which the machine measures) isn’t that hard. However, you’ll be caught quickly because, for the first 20 minutes, you’ll be asked simple test questions to calibrate the polygraph specifically to your responses.

If you show up to the test under the influence, hungover, or sedated with tranquilizers, Valium, or valerian to “calm your nerves,” an experienced polygraph examiner will notice immediately. Your uniform reactions to all questions might not prove you’re lying, but they won’t help you either. Most likely, your results will simply be voided. The point isn’t to suppress all emotions, but to produce the right reaction at the right moment to key questions.

How to Outsmart the Polygraph

Your goal during the polygraph is to trigger false reactions to harmless questions that could theoretically make you nervous (like questions about your family), and to hide your emotional responses when lying to provocative questions.

You can achieve this by using physical stimuli, such as pressing a button in your shoe or tensing muscles (preferably not facial muscles, as those are easy to spot), or by distracting your mind. Try thinking about something arousing, doing mental math, or focusing on a pattern on the wall. Combine these fake reactions with emotion-suppressing methods like alcohol, chemicals, sleep deprivation, or drinking lots of water beforehand so you really need to use the bathroom (a surprisingly effective trick). This way, you’ll only react to harmless questions that could plausibly make you nervous.

The ideal way to beat a polygraph is through acting. Any good actor trained in the Stanislavski system can pass a polygraph by simply believing their own lie. If you truly believe your made-up story, it becomes your reality, and your body will react as if it’s the truth. If you’re not an actor, here are some effective tips, including some from NLP techniques:

• Prepare your lie in advance, down to the smallest details, so you can talk about it for hours as if recalling real memories.
• Focus on sensory details—colors, smells, your mood at the time. These “circumstances” help you immerse yourself in your story.
• Don’t be afraid of showing emotions; use them to your advantage by transforming one emotion into another (e.g., turn fear into anger, remorse into acceptance).
• Reframe questions in your mind to make them more comfortable for you. For example, if asked whether you took medication today, think about how the pills harmed you rather than helped, eliminating the internal conflict the polygraph detects.

To control blood pressure, try tensing your sphincter muscles (as if you’re trying not to go to the bathroom) or gently biting your tongue between questions—just don’t make it obvious. Do this between questions or when the examiner is distracted.

Finally, pay attention to your breathing. Normal breathing is about once every 2-4 seconds. Don’t hold your breath, as it increases your heart rate.

Part 2: Methods to Counter the Polygraph

There’s a widespread myth about the super-effectiveness of polygraphs. Mistakes are often blamed on unqualified examiners, but the technology’s reliability is rarely questioned. Media often cite “authoritative data” claiming 90-95% accuracy or higher. This myth is promoted by polygraphers and interested parties to create commercial demand and to psychologically pressure test subjects, making them less likely to resist and thus increasing the test’s effectiveness. This approach helps “win the battle before it starts.” There are also deeper social-psychological reasons: throughout history, fear and awe of mysterious powers have been used to control people. The myth of the polygraph’s power is no exception, and “bosses” use it to keep subordinates in line.

Every polygraph examiner tries to convince the “victim” that resisting the polygraph is pointless. During the briefing, you’ll be told in a friendly manner that the lie detector “sees everything” and can’t be fooled. You’re supposed to relax and “enjoy” being probed for your deepest secrets. Don’t blame the specialists—it’s part of their job. But can you really beat the polygraph?

Despite advances in science and technology, the real effectiveness of polygraphs is still far from the claimed numbers. There have been many errors and scandals where polygraph results ruined innocent lives. Even in the U.S., where polygraph use is widespread and examiners are highly trained, independent experts estimate accuracy at best around 70%. Lab and field studies show significant error rates, and experiments have proven that people can be trained to beat the polygraph. So, while it’s difficult, it’s definitely possible to outsmart a lie detector.

First, overcome the fear and awe instilled in you. Remember, the polygraph can’t read your mind or learn your secrets. It only records your physiological state during the test—changes in your body as you answer questions. The computer then gives a probability assessment, which a specialist interprets. Like any machine, the polygraph can be tricked or overloaded so it can’t give a clear answer.

Pathological liars can easily confuse the polygraph, as their bodies react to lies as if they’re telling the truth. Professional actors, especially those trained in the Stanislavski system, can also pass by fully embodying their character. Intelligence agents with special training are another group. For everyone else, it takes practice and training. Some people are naturally gifted, but they’re rare.

Three Main Methods to Counter the Polygraph

1. Reduce your sensory sensitivity. Drinking alcohol the night before can dull your reactions, making your responses “sluggish” and less responsive to stimuli. The polygraph won’t be able to draw clear conclusions.
2. Use medication. Certain drugs can help, but you must know how your body reacts. If you take psychotropics for the first time, you might behave oddly, which will be noticed. Non-chemical methods include sleep deprivation—after several days without sleep, your reactions become uniformly weak. However, an experienced examiner will notice this and may postpone the test.
3. Suppress all emotions. Try to answer all questions automatically, focusing on a neutral object or memory. This requires concentration and practice but can be effective.

Another approach is not to suppress all reactions (which is easily detected by control questions), but to produce the right reactions at the right times. Fake emotional responses to irrelevant stimuli can be effective. For example, do mental math or think about something that triggers a strong emotion when you want to show a reaction. If you want to hide your sexual orientation, do math when asked about women. If you want to appear homosexual (e.g., to avoid the draft), do math when asked about same-sex attraction. Alternatively, imagine sexual scenes that trigger a reaction at the right moment. You can also silently recite poetry to yourself, like “Eugene Onegin,” to distract your mind.

Pain can also trigger stress reactions. Some people put a tack in their shoe to press on during harmless questions, creating fake reactions. Other methods include tensing muscle groups discreetly—pressing your toes to the floor, crossing your eyes, or pressing your tongue to the roof of your mouth. The challenge is to hide these movements, as even amateur examiners know these tricks. You may be filmed, so be careful—any suspicious behavior will be interpreted against you.

As an alternative to physical tricks, try NLP techniques like setting a “psychological anchor” for tension or relaxation and using it at the right moment. Mental tricks are the hardest to detect and, if used correctly, can lead the examiner to the wrong conclusions.

Example from Literature

Here’s an example illustrating the principle of tension/relaxation from Harry Harrison’s “The Stainless Steel Rat’s Revenge”:

“We are conducting an intensive search for this spy. Since you gentlemen were near the scene, I intend to question you one by one to find out what you know. I can also detect… Who among you is the missing spy?”
This last arrow was met with stunned silence. Now, with us all in a subdued state, the gray man began calling officers in one by one. I was grateful for my foresight in fainting in front of everyone.
I was called third. Why? Maybe I resembled the spy, or because of my bandage. There must have been some reason. I shuffled forward, saluted, and he pointed to a chair by his desk.
“Why don’t you hold this while we talk?” he said, handing me the silver polygraph sensor.
I looked at it with mild interest, as if I didn’t know it was transmitting vital information, and squeezed it in my hands. My thoughts were less calm.
I’m caught! He knows who I am and is toying with me.
He looked deep into my bloodshot eyes, his mouth curling in disgust.
“Rough night, Lieutenant?” he asked, glancing at the polygraph readings.
“Yes, sir, had a few drinks with the guys,” I replied aloud. In my mind, I thought: they’re going to shoot me dead, right in the heart! I imagined my heart spilling blood into the dirt.
“I see you were recently demoted… Where are your detonators, Pas Ratunkov?”
“I’m tired… I wish I were in bed,” I thought.
“Detonators?” I blinked and, raising my hand to scratch my head, touched my bandage and thought better of it. His eyes bored into mine, and for a moment I sensed his strength and anger.
“And your head wound, where did you get it? Our spy was hit on the side of the head.”
“I fell, sir, someone must have pushed me from the truck. The soldiers bandaged me, ask them…”
“I already did. You got drunk, fell, disgraced the officer corps. Get out and clean up, you disgust me! Next!”
I got up unsteadily, not looking at his cold eyes, and left, dropping the device on the table as I went. He ignored me, bent over his papers. I noticed a faint scar on his bald head and left.
To fool a lie detector takes skill, practice, and training. I had all of that. It can only be done under certain circumstances, and these were ideal: a sudden interrogation at night, with no baseline tests. I had to produce a nice spike on his chart. I was afraid—of him, of anything. But when he asked the key questions, I relaxed, because I expected them, and the device showed it. The question was meaningless to anyone but the spy. Once he saw that, the interrogation was over; he had more work to do.

Additional Tips and Reader Advice

For English speakers, check out Antipolygraph.org, a site dedicated to fighting polygraph use. Their motto: “They have the right to try to learn everything about us; we have the right to tell them to get lost… That’s democracy.” The site features “The Lie Behind the Lie Detector,” offering methods to counter “unscientific testimony techniques that only work in lawless countries.”

These recommendations apply to classic polygraphs, which measure blood pressure, breathing rate, blinking, heart activity, skin conductivity, brain activity, and involuntary movements. When hooked up, pay attention to your breathing—normal is 15-30 breaths per minute (about every 2-4 seconds). Rapid or slow breathing is considered a sign of lying. After a “dangerous” question, a “sigh of relief” often follows, so control your breathing until you’re fully disconnected from the wires.

To fool blood pressure sensors, enthusiasts suggest tensing your anal sphincter and gently biting your tongue between questions. Tense your muscles without moving your legs or buttocks, as modern polygraphs have sensors in the chair to detect even slight movements.

These techniques can also be used during regular interviews, such as with a psychologist or HR specialist, since they also watch your reactions closely to determine if you’re telling the truth.

Finally, here’s a unique method from a reader:
If you want to beat the polygraph, drink lots of water before the test so you really need to use the bathroom. Try to time it so you’re only slightly uncomfortable during the initial “calibration” questions (the first 10-30 minutes). Then, during the main questions, focus all your attention on your bursting bladder. The overwhelming urge to pee will dominate your thoughts, making it hard to think about anything else, including the questions. This can help mask your reactions and confuse the polygraph.