Polygraph Information
Everything you need to know about Polygraph (Lie Detector) Testing
A polygraph exam is a diagnostic procedure used to determine the truthfulness of an individual by using a polygraph instrument. This web site is designed to inform and advise those persons interested in Psychophysiological Detection of Deception (PDD) a/k/a Polygraph a/k/a Lie Detector testing.
Polygraph testing, also known as lie detector testing, is the most reliable method today for determining whether an individual has been truthful regarding a particular situation. Unfortunately, the public has been subjected to significant misinformation regarding polygraph, its functions and capabilities. We will attempt to clarify the nature of polygraph testing and dispel some of the inaccurate information available.
Polygraph testing, also known as lie detector testing, is the most reliable method today for determining whether an individual has been truthful regarding a particular situation. Unfortunately, the public has been subjected to significant misinformation regarding polygraph, its functions and capabilities. We will attempt to clarify the nature of polygraph testing and dispel some of the inaccurate information available.
Reality Check #1 - There is no such thing as a lie detector
People lie for a variety of reasons. Some are so-called "white" lies, like "You sure have a nice car." Some are more serious, like "No, I didn't rob that bank." And then we have many lies in the middle range, such as "I have a great deal of experience working with this type of software." In reality, nothing special takes place in the brain when we tell a lie. There is no such thing as a "lie response." In other words, just because you tell a lie doesn't mean you will have a reaction to it, and if you do, it will be a different reaction than someone else would have. So if polygraphs don't detect lies, what do they detect?
Evolution has designed humans (and most animals) with a self-defense mechanism that is activated whenever we are threatened or placed in danger. For example, if you are walking along a path and come across a poisonous snake, your body and brain will have a reaction to that snake because you realize it could hurt you. This realization automatically triggers your body's self-defense mechanism as it tries to help protect you. Within a few seconds some typical reactions occur: Adrenaline is released to improve your alertness, additional blood is sent to your muscles in case you need to defend yourself physically, your skin glands become more active in preparation for a physical response, your digestive process slows down, and your breathing changes. After this reaction takes place, you are better prepared to deal with the crisis you are faced with and can make a conscious decision about what to do.
What is more important than the lie itself is the reason for telling the lie. When we do something wrong, such as commit a crime or do something we know we shouldn't have done, we realize that if we get caught that we will be punished. This punishment might be imprisonment, embarrassment, loss of a present or future job, loss of money, or loss of a relationship. Our instinct for self-preservation makes us want to avoid being punished for what we did. This is usually accomplished by lying.
In other words, lying in most cases is an act of self-defense. We usually lie to avoid punishment. Being caught in the lie means we will be punished. It is our understanding of the consequences that triggers the body's self-defense mechanism when we lie. The polygraph instrument is a finely tuned medical device which will record various aspects of your body's Sympathetic and Parasympathetic Nervous Systems and will recognize when your body's self-defense mechanism has been activated by lying. It isn't the lie that makes a polygraph work, it's the understanding that there are consequences to being caught in that lie. Our bodies create self-defense reactions to try to avoid those consequences.
Evolution has designed humans (and most animals) with a self-defense mechanism that is activated whenever we are threatened or placed in danger. For example, if you are walking along a path and come across a poisonous snake, your body and brain will have a reaction to that snake because you realize it could hurt you. This realization automatically triggers your body's self-defense mechanism as it tries to help protect you. Within a few seconds some typical reactions occur: Adrenaline is released to improve your alertness, additional blood is sent to your muscles in case you need to defend yourself physically, your skin glands become more active in preparation for a physical response, your digestive process slows down, and your breathing changes. After this reaction takes place, you are better prepared to deal with the crisis you are faced with and can make a conscious decision about what to do.
What is more important than the lie itself is the reason for telling the lie. When we do something wrong, such as commit a crime or do something we know we shouldn't have done, we realize that if we get caught that we will be punished. This punishment might be imprisonment, embarrassment, loss of a present or future job, loss of money, or loss of a relationship. Our instinct for self-preservation makes us want to avoid being punished for what we did. This is usually accomplished by lying.
In other words, lying in most cases is an act of self-defense. We usually lie to avoid punishment. Being caught in the lie means we will be punished. It is our understanding of the consequences that triggers the body's self-defense mechanism when we lie. The polygraph instrument is a finely tuned medical device which will record various aspects of your body's Sympathetic and Parasympathetic Nervous Systems and will recognize when your body's self-defense mechanism has been activated by lying. It isn't the lie that makes a polygraph work, it's the understanding that there are consequences to being caught in that lie. Our bodies create self-defense reactions to try to avoid those consequences.
Reality Check #2 - Polygraph exams are correct 90% of the time
Polygraph results are accurate about 90% of the time. In fact, new industry standards require that a particular technique be at least 90% accurate for that technique to be "validated." Make sure your examiner is using a validated polygraph technique.
Reality Check #3 - Polygraph is a procedure, not a machine
A polygraph examination can take from 1 to 3 hours or longer in some cases. There is a great deal of data that must be collected before the test begins, and the person being tested (called the "examinee") must be interviewed regarding the main ("target") issues, and then a series of questions is designed by the examiner for that specific situation. All of the test questions are reviewed with the examinee before the test begins. The examinee is then connected to the polygraph instrument and then the exam is done between 3 to 6 times. The instrument simply collects the data while the test is being done. This data is in the form of charts, or polygrams, which records various bodily functions while the questions are being asked. After the charts are collected, the examiner must apply the industry-standard scoring rules to the data before rendering a decision.
Reality Check #4 - There are global standards for polygraph testing
Reality Check #5 - What you see on television is not real (most of the time)Reality Check #4 - There are global standards for polygraph testing
Both the American Polygraph Association and the American Society for Testing and Materials have established standards for the conducting of polygraph examinations. There are myths that polygraph examiners can make a polygraph come out any way they want, but if the published standards are applied correctly and uniformly, most examiners will agree with the results of any particular exam. Polygraph techniques will continue to evolve and improve, and the use of uniform testing methods will insure that all examiners are working from the same set of rules. Make sure any examiner you hire is conforming to APA and ASTM polygraph standards.
Most people get their polygraph information from watching television shows... reality shows, court shows, talk shows. In most cases these exams are staged for the cameras, producers and the audience, and are NOT REAL. Here are some things you should know about polygraphs on television:
- Polygraph exams can not be done in front of an audience
- Polygraph exams must be done in a controlled environment with no distractions
- Polygraph questions must be reviewed with the examinee before the test
- Polygraph accuracy goes down as you add questions. There is usually a limit of 3 to 4 relevant questions per exam.
- Polygraph answers are limited to "yes" and "no." No narrative answers are permitted
- Polygraph questions are spread out so that it is clear which question is causing a reaction. The average time between questions is 20 to 30 seconds.
- Movement by the examinee causes distortions with the test results. If the examinee is moving during the exam, no reliable data can be collected.
- Polygraph exams must be done at least 3 times before a decision can be rendered. Each question must be asked at least 3 separate times during the procedure.
- Polygraph exams take at least one hour if done correctly. Most TV shows will not allow that much time for an exam.
Reality Check #6 - There are some very bad polygraph examiners out there
Just as there are other
professionals with varying degrees of expertise, so is it within the
polygraph profession. There are high-quality examiners and low-quality
examiners, and some are outright frauds with no polygraph training at
all. Less than half of the U.S. states require polygraph licenses, so
it is the customer's responsibility to do his/her homework and select
the best examiner for their needs. Shopping by price alone is the worst
way to pick an examiner and virtually guarantees that you will not be
satisfied with the service. Not all examiners are created equal. Click HERE to find out how to hire an qualified examiner.
Information provided by R. Michael Martin, Court-qualified polygraph expert and owner of the Global Polygraph Network
