Is it Possible to Fail a Polygraph Lie Detector Test?



One Quora user even shared their experience of getting a false positive test result when applying for a police officer position. The person was honest and truthful during the exam, but the polygraph results came back wrong.

There are several reasons that can make you appear guilty on a lie detector test despite telling the truth. Some of the main ones are stress and fatigue, lack of a good night’s sleep, and inexperienced examiners.

False positives

A polygraph, or “lie detector,” is a device that uses sensors to measure changes in blood pressure, heart rate, respiration, and perspiration, reactions that are supposedly linked to deception. It was first invented by William Moulton Marston in the early 1920s, and it’s been used by police ever since.

Movies and TV shows often show liars avoiding eye contact, covering their mouths, making mistakes when answering questions, touching their bodies, fidgeting, etc. The truth is that these behaviors don’t help you beat a lie detector test, and they can be caused by many different factors.For more info, do visit this website Octopus Energy Referral.

Other factors that can skew results include fatigue, anxiety, eating, drinking, smoking, and medications. While these don’t enable you to “beat” a polygraph test, they can make it more difficult for the examiner to accurately assess your response. In addition, pregnancy can increase your heart rate and blood pressure, and it may affect the results of a polygraph test. As a result, most examiners won’t test pregnant women unless they have written approval from a doctor.

False negatives

Taking a lie detector test is a stressful experience. It is often used as a tool to detect deception by measuring a person’s heart rate, blood pressure, and perspiration in response to specific questions. The test is based on the assumption that liars will exhibit these responses while truth tellers will not.

There are many myths about how to beat a lie detector test, but most of them don’t work. Biting your tongue or putting a tack in your shoe won’t affect blood pressure or cause you to sweat, and it also won’t change the way you answer questions.

People who are able to control their physiological responses and convince themselves they are telling the truth can easily pass a polygraph test. Unfortunately, false negatives can have serious professional and legal consequences. The Employee Polygraph Protection Act prohibits employers from requiring that employees or job applicants take a lie detector test or discriminating against them on the basis of the results of a polygraph test.

The test’s reliability

Regardless of whether it is used to detect infidelity or to determine the truth behind a missing person’s disappearance, a private lie detector test can help couples uncover the facts about what really happened. However, the results of the test are not foolproof and can be manipulated by the examiner.

In fact, the tests can be so inaccurate that they can present innocent people as guilty. This is because of the stress a person feels during a polygraph. This can result in an elevated heart, respiratory and blood pressure rate. These signals can be picked up by the polygraph machine and recorded on a piece of moving graph paper.

Furthermore, a lot of the techniques employed by the polygraph have been found to be unreliable and even crude racial profiling. For example, Wired analyzed data from the TSA’s SPOT program and found that not only do “failure” rates for various supposed lies vary widely from one examiner to the next, but black people have been disproportionately “failed” on these tests.


Several websites claim that you can beat a lie detector test by using countermeasures. These involve modifying your behavior during the test to manipulate your physiological responses. Some of these methods involve acting distraught during the entire test, and others suggest lowering your heart rate, respiration, or blood pressure. Medications, such as antihypertensives and anti-anxiety drugs, can also affect polygraph results.

Other techniques include daydreaming or imagining something that calms you to control your physiological response. Some people have even used pain to improve their results. However, many of these countermeasures are easily detectable by examiners. Moreover, they can make you appear guilty when you’re not. Many guilty people in notorious cases, including Green River Killer Gary Ridgway and Russian mole Aldrich Ames, have passed polygraph tests. Other techniques for detecting deception, like eye-tracking and fMRI brain reading, have been shown to be unreliable in practice, as well. In addition, there is no consensus on how deception actually works.