What is a Polygraph?
A polygraph (popularly referred to as a lie detector in the UK) measures and records several physiological indices and physical changes in a person under questioning and correlates this with principles of psychology. A skilled examiner conducts the test and measures changes in such variables as heart rate, breathing and perspiration in addition to psychologically evaluating the person. The psychological part of the test is used to identify the specific issues and formulate a physiological profile of the examinee. The the physical part (polygraph) of the test uses the technical instruments to detect signs of deception and verification of the truth. The examiner then combines their analysis from both the physical and psychological testing to draw conclusions and provide this in a professional report. The Lie Detector Test is used globally in personal, criminal and legal matters, and with the success of such shows as Jerry Springer and Jeremy Kyle, is predominantly used to resolve personal matters like relationships, false accusations and family disputes.
How reliable is a Polygraph test?
The polygraph is highly reliable, providing the examiner is properly trained and using the latest validated techniques and computerized equipment. The American Polygraph Association (APA) has gathered over 200 studies on the subject. Based on twelve separate studies involving 2174 actual cases since 1980, evidence suggests that qualified polygraph examiners are 98% accurate in their overall decisions. The use of the polygraph has evolved over the last ten years; techniques are now backed by science and accuracy with the latest computerized equipment.
What happens during a Polygraph test?
The polygraph test usually takes around 2 hours depending on the complexity of the issue and the particular person to be examined, but can take up to four hours. The test comprises of the following: The first section being the pre-test interview where a statement of consent to conduct the test is obtained, the issue is discussed and the specific questions are formulated. There will be an explanation of the equipment being used and background data is gathered from the examinee.
The second section is the data collection phase which includes attaching the sensors to the examinee, which includes upper body movement sensors attached to the chest. A standard blood pressure cuff is attached to the upper arm and is inflated, to record reading of the examinees heart rate and pulse rate. Electrodermal activity finger cuffs are attached to two fingers to measure skin conductance (sweat gland activity). The examinee sits on a movement sensor mat. Once complete the examiner will analyse the results and provide an opinion as to the truthfulness of the person taking the test depending on the test type. You will get the results the same day verbally via a phone call, followed up by a written report emailed or posted.
Can you fail a Polygraph test if you are nervous?
Being nervous before a polygraph exam is normal and not at all unusual. If anything, the examiner will think it suspicious if you are not nervous! Being nervous will not cause a person to fail a polygraph test, not telling the truth will. It is very normal for an innocent person to feel nervous and the examiner is very aware of this. Nervous reactions which are recorded on the polygraphic charts are not interpreted by the examiner as a manifestation of deception. Nervous reactions are completely different from those reactions that are recorded when a person is deliberately lying.
Is it possible to beat or cheat the test?
Using modern equipment and the latest techniques it is highly unlikely. The polygraph records changes in a person’s autonomic reactivity whilst they answer questions. If an examinee attempts to distort the polygraph tracings, it becomes evident to a trained examiner during the test. It is easy for a qualified examiner to spot when an examinee is attempting to alter the outcome of a test, even if they are attempting to bite their tongue or tense their rectum and other methods they may have read about on the internet. This can result in the test being abandoned.
Does the polygraph testing equipment hurt?
During the test, you will be linked up to a series of sensors, and these will cause you no pain. Sensors will be attached in the following areas:
- Around the upper chest and stomach to monitor breathing and movement
- On the fingertips to measure skin conductance and sweat gland activity;
- A blood pressure cuff on your arm to monitor changes in blood pressure, blood volume and pulse rate. This is similar to the cuff your doctor might use, and will be inflated throughout the test. This may feel slightly uncomfortable, but no more than usual with your doctor.
Where can tests be run?
We have set up a network of private controlled and discreet offices which match the criteria to ensure a safe and accurate test can be conducted across most major towns and cities across the US and Canada. For further information on prices and availability, please contact a member of our customer service team. If you prefer, the examiner can travel to your home to conduct the test, however we would require a distraction free environment with a table and two chairs. At extra cost, tests can be completed anywhere in the world and generally within ten days of the initial enquiry (subject to visa and other contractual requirements).
How many questions and what questions can be asked?
Throughout the test you will be asked many questions. When you first arrive, you will have a pre-test interview with the qualified examiner which is, in effect, an extended consultation where the psychological profile commences so either yourself or the person you have proposed to be tested can expect to be asked a lot of questions about the history behind the issue at hand. For example what has gone missing and when, or who was about for a theft case, or about the relationship before focusing on a cheating accusation.
Once the test begins, you will be asked a series of questions for building the psychological profile of the person being tested, and there will be up to 3 close ended questions specific to the test issue. The examiner will also assist in the formulation of the specific questions to make sure that the questions which you wish to propose are both worded correctly and focused on resolving the issue. The examiner will also where necessary make contact before the test to go over the questions. There is no issue with the person being tested having knowledge of the questions beforehand as they cannot prepare for the specific format and technique the skilled examiner will use.
Please note, the answers for all questions will not be included in the verified report you receive after the exam. The report will consist of only the questions specific to the case.
What languages can test be run in?
We can conduct Polygraph tests in any language with the help of a team of highly specialist interpreters, however there will be extra costs associated with this.