Find Out More About Lie Detector Testing
Gathered from clients across the years, my Frequently Asked Questions are designed to help you understand various aspects of the polygraph testing process, for your confidence and peace of mind.
If you have any additional questions, don’t hesitate to get in touch for an informal chat or to book your free initial consultation. I’m here to help with any query you may have, so that no worries remain, for total peace of mind.
What is a polygraph or lie detector test?
Polygraph tests are the most popular method of ‘lie detecting’. They measure physiological reactions such as changes in sweat gland activity, pulse, blood pressure and respiration, and produce a score based evaluations of a person’s trustworthiness based on evidenced scoring systems.
During the test, you will face three types of questions:
Irrelevant questions such as “are you wearing x piece of clothing” designed to provoke no emotions for a baseline response.
Diagnostic questions where the subject is likely to lie, such as “have you ever stolen anything”.
Relevant questions which are related to the matter at hand.
Based on comparing the subject’s physiological responses in the three sets, the tester can make assertions towards the truthfulness of the subject.
How accurate is a polygraph or lie detector test and can it tell the difference between lying and nervousness
Modern testing is based on a rigorous, century line refinement process. Whilst it is not infallible, it is generally considered to be the most accurate scientific test for distinguishing whether someone is being deceptive.
The tests don’t identify physiological reactions that are specific to lying, but rather track general arousal, as the fear of being caught in deception or lying tive or lying causes physiological reactions. As a consequence, the most important part of an accurate polygraph test is the experience of the individual administering it. When interviewing a victim or someone who is impassioned in their innocence, an untrained tester may be unable to distinguish lies from the truth due to the present emotions. However, according to Newcastle University’s Professor of Forensic Psychiatry Don Grubin, a properly administered test by a trained examiner is as much as 95% accurate.
Building on 35 years of investigative work and extensive training at the American international Institute of Polygraph, you can be assured that Lies2Light’s testing scheme is as accurate as they come.
How many questions can be asked in the test?
Three close-ended questions related to the matter in question can be asked, with a yes or no answer. Questions about emotions, feelings or thoughts cannot be asked.
What is having a polygraph or lie detector test like?
Contrary to popular belief, polygraph or lie detector tests by themselves are not a stressful or painful experience. There is no electrical tingling and measuring blood pressure is done in the same way as you would do at home. Perhaps the most uncomfortable part of a polygraph test is the discussion. Often the test involves questions on traumatic or emotive experiences, which in some circumstances can be distressing. By ensuring privacy and accommodating your needs, our controlled process creates an environment designed to counter the potential stress of a test.
Is it possible to cheat the test?
As a short answer, no. It is possible to distort the results of polygraph or lie detector tests, as the test is based on comparing baseline results from the irrelevant and diagnostic questions to the relevant ones. Thus, subjects who distort their baseline may affect the test.
However, the methods involved in doing this are often detectable. As part of training in their usage, testers are taught methods of assessing the results in order to identify subjects who have attempted to cheat it. As the purpose of polygraph or lie detector tests is to assess whether a subject is being deceptive, uncovering an attempt to cheat the test is suspicious in itself.
Can medication affect the result?
Certain medications can affect the ability of polygraph tests by causing an inconclusive result. As polygraphs physiological arousal to measure truthfulness, medication that affects heart rate, blood pressure, sweating or respiration can affect the test. However, there is no medication or drug that will help someone beat a test.
Polygraph tests can be recalculated according to medication. As part of our pre-test process we will evaluate the medication you take in order to ensure the test is properly administered.
