The polygraph test machine is usually called the lie detector. This is most commonly used in criminal investigations. This machine is actually helps in measuring the nerve excitement. There is a premise on which it works that if the subject is telling the truth then he will remain calm.
There was a old technique called trial by ordeal. So, lie detector can be understood as the modern variant of this. But in modern polygraph tests, no one will die. Along with this the results are usually inadmissible when subjected to court of law. Polygraph machines available today usually measure the increase pulse rate and sweating with exquisite accuracy. In their conception they are crude. But when it comes to detecting liars, they are considered no more sophisticated in comparison to ancient ordeal. Today there are many service provides who help in the process of lie detection and one among them is lie detector testing service.
Does the polygraph work?
Even today there are many controversies when it comes to the working of the lie detectors. But experts have opinion that the subjects who failed in polygraphs, usually confessed to crimes. There may be lot of false positives from the outcome of the tests. This is nothing but in many cases even though people are telling the truth, the polygraphs test for same person says that they are lying.
But few polygraph association says that one can receive an accuracy of 90 percent from a polygraph test. But few other experts say it is just 65 percent. So, in some cases it may easily detect liars but in some other case, it may point a honest person.
Can The Lie Detector Test be Faked?
One thing to understand is that polygraph tests are bad enough because they prompt few researchers to loot at more direct lying by the process of analyzing the brain scans. Along with this one more negative about this test is that it can easily be faked.
The techniques used in the polygraph tests are based on the responses which are considered true. So, they judge the deceptive answers based on the variation in the nervous arousal. So, to fake the test, one needs to raise the arousal. So, it is not easy to detect the raised arousal behind the lies when a person raises the arousal for honest answers.
How do we stop this?
So, when the test is faked, it can affect the examiners judgment of the results. In this case they may also look at the thing that polygraph’s how much part indicates lying. There was a research which concluded that polygraph tests lack in scientific validity. This is the reason in some countries this cannot be used in legal proceedings. Even defence attorneys cannot use this. Along with this, in many other settings polygraph tests are discredited. Majority of the employers today cannot use it to recruit honest individuals. To administer the polygraph tests there is no rationale when we see from scientific perspective. So, if it is possible to avoid this, then better to do so. Sometimes the polygraph tests may also lead to self incrimination.