There are a number of factors that can influence the accuracy of a lie detector test. These include the examiner’s level of training, their personal beliefs and biases, and the way the questions are framed.
Some medical conditions and medications can also interfere with the results. And some people, such as sociopaths and psychopaths, can beat the machine.
Lie Detector Tests
While they are often portrayed as inaccurate on the Maury Show or other TV shows, lie detector tests can be an excellent tool to help investigators find out if someone is lying. These tests analyze a person’s autonomic responses to questions to determine their level of truthfulness.
They can also detect the typical stress responses that occur when someone is lying. These include increased heart, blood pressure, and respiration rate. Many people who are able to control their anxiety or simply know how to tell the truth can pass these tests. Even spies like Aldrich Ames, who worked for the Soviet Union, were able to pass polygraph tests by following the advice of their supervisors: simply relax.
Despite this, there are some ways to manipulate or fool a polygraph test. Having a skilled examiner is crucial. Just like with driving lessons, a quality examiner can make a big difference in the results of a test. Get more info on this Lie Detector Test website.
Polygraph Tests
Being told you have to take a lie detector test can be a frightening experience. Even though the test is designed to measure changes in a person’s heart rate, respiration and perspiration during questioning, it can be difficult to tell whether or not they are lying.
Despite sensational news stories and Hollywood dramatizations of people beating the polygraph, it is important to remember that these tests are not foolproof. The American Polygraph Association, an organization that includes professional polygraph examiners, estimates that a single issue test is 87% accurate if conducted by a trained examiner using validated techniques.
Nevertheless, the fact remains that it is possible to beat a polygraph test if you know how to go about it. It takes a great deal of preparation and practice to be able to fool the machine, however. In addition, Wired uncovered police department data and lawsuits that showed not only do “failure” rates for various supposed lies vary wildly from one examiner to another but that black people are far more likely to be incorrectly declared as guilty of lying than whites.
Pre-Test Interview
During the pre-test interview, your examiner will record your responses to a series of questions. These answers are compiled into behavior clusters that indicate truth or deception. They are used to build the questions for the in-test phase. He will also ask you about your medical and psychological history to identify any conditions that could affect the results.
The examiner will then attach sensors to monitor your heart rate, blood pressure and breathing, and begin asking the control questions. These are designed to arouse your baseline anxiety in order to compare it with the level of anxiety you experience when lying.
The examiner will also try to manipulate you into blanket denials of minor misdeeds. For example, he will ask you, “Have you ever cheated on a test?” or, “Have you ever lied to someone in authority?” The polygraph operator assumes that all people have cheated on tests and lied to people in authority at some point, so he wants Bob to deny these minor transgressions.
Post-Test Interview
When you take a polygraph test, you are asked questions that provoke specific behavioral symptoms that are associated with lying. These include heightened heart and respiratory rates, higher blood pressure, and activation of three areas of the brain. These responses are recorded by sensors attached to your body and translate into digital signals.
The examiner will start by asking several simple questions to establish a baseline for your responses. You will then be asked more relevant questions that are paired with a control question. The examiner will use the data gathered to determine whether you are telling the truth or not.
Many people who are accused of a crime have to undergo a polygraph test as part of their legal case. They may also be required to take one for certain jobs, including the military and law enforcement. The test is not foolproof, and there are ways to beat it. Some of these tricks, such as biting your tongue to raise your heart rate and putting a tack in your shoe to increase perspiration levels, won’t work because they don’t establish differences between telling the truth and lying.
