Myth #1 – A polygraph is a lie detector. The Truth: Polygraph is a procedure which records a person’s physiological changes while being asked a series of carefully designed questions. The data collected can then be correlated to the probability of truthfulness. No technology exists that can measure a lie directly.
Myth #2 – Polygraph lie detector is not accurate. The Truth: A single issue polygraph test is validated at 93 to 95 percent accuracy, according to scientific research. Click HERE for more info.
Myth #3 – Polygraph lie detector can easily be beaten. The Truth: Examiners are trained to watch for countermeasures. Most efforts to beat a polygraph are easily recognizable and will cause a person to fail the exam. Click HERE for more info.
Myth #4 – Nervousness will make a person fail a polygraph lie detector. The Truth: Nervousness and anxiety are generalized conditions that will exist through the entire exam, not just on one or two questions. Being nervous will not affect the test results.
Myth #5 – A polygraph lie detector can include as many questions as you want. The Truth: Accuracy of a polygraph varies with the number of questions. Asking just one question is the most accurate testing method. The maximum number of questions is four, which is the least accurate test. Click HERE for more info.
Myth #6 – Polygraph is never admissible in court. The Truth: Polygraph testimony has been accepted in many U.S. courts, but admissibility varies by jurisdiction and by judge.
Myth #7 – A polygraph lie detector takes less than 30 minutes. The Truth: APA Standards require an exam to take at least 90 minutes. A properly administered exam will take between 90 minutes and 2.5 hours. Any examiners doing a test in 45 minutes or less is not providing a real exam. Click HERE for more info.
Myth #8 – Polygraph results are available instantly. The Truth: The exam questions must be asked several times (typically 3 to 12 times each) then numerically scored. It is the total of the individual scores that determines the outcome of the exam. One presentation of a question does not contain enough information for the examiner to analyze. APA Standards prohibit issuing results until the charts have been numerically scored.
Myth #9 – High blood pressure will affect lie detector results. The Truth: Since polygraph exams only measure physiological changes between test questions, the person’s blood pressure (high or low) at the beginning of the test is irrelevant to the test results.
Myth #10 – A polygraph lie detector can test for thoughts, feelings and emotions. The Truth: These are unreliable issues for a lie detector test because the issues do not deal with factual non-subjective subject matter. Even the slightest doubt can create an incorrect test result.
Myth #11 – Each polygraph lie detector question gets a separate result. The Truth: Research has discovered that making decisions about individual test questions is a very inaccurate method. The more reliable scoring method is a universal score, incorporating an analysis of all the questions.
Myth #12 – A pathological or compulsive liar can beat a polygraph lie detector. The Truth: A polygraph determines whether a person is being intentionally deceptive, to a high degree of accuracy. If a person knows they are lying, and understands the consequences, the lie detector test will work as designed. Click HERE for more information.
Myth #13 – Medications can change a lie detector result. The Truth: Medications of any kind will affect all the questions equally. Since we only look for variations between individual questions, use of most medications will not affect the outcome. However, if the medication reduces a person’s reactions beyond the point they can be analyzed, the test will be inconclusive.
Myth #14 – A polygraph result of “inconclusive” means that person failed. The Truth: A result of inconclusive simply means that the examiner can not determine the probability of truthfulness at that time. Is not a test failure. Click HERE for more information.
Myth #15 – A child can not be tested with a polygraph lie detector. The Truth: Many examiners will test a child of normal intelligence with written parental consent. The minimum age allowed is up to each examiner, although the youngest age any examiner will test is 12. Click HERE for more information.
Myth #16 – A valid polygraph (in the United States) can cost less than $200. The Truth: In most cases, any examiner charging that small a fee is most likely a scam. The examiner probably never attended polygraph school and is not APA accredited. Click HERE for more information.
Myth #17 – Polygraph lie detector can read minds. The Truth: Polygraph measures elements of the Sympathetic Nervous System which are related to intentional deception. In other words, whether a person did something or did not do something. Polygraph is very poor at analyzing thoughts, feelings, and intentions, as those are not factually-based issues. Click HERE for more information.
Myth #18 – Asking more than one question makes the polygraph test more accurate. The Truth: The opposite is true. Focusing the exam on one narrow issue is much more accurate than covering multiple topics within the same exam. Click HERE for more information.
Myth #19 – A polygraph examiner must be licensed. The Truth: Less than half the U.S. states require licensing for polygraph examiners. In other states, there is no license available, so an examiner in those states will not possess a license in that state. Click HERE for more information.
Myth #20 – Eye Scan (EyeDetect) technology is just as accurate as polygraph lie detector. The Truth: EyeDetect has twice the error rate (12 to 14%) that a single-issue Polygraph has (5 to 7%). Click HERE for more information.