A lie detector or a polygraph test can be used by law enforcement agencies, attorneys, parole offices, and other offices that are authorized by the government. The polygraph test is used to judge whether you are lying or not depending on your heart rate, skin conductivity and breathing when you are asked a question. Certain parts of the devices will be attached to you that will help the examiner record your readings. Nowadays most of these tests are computerized and a computer system assembles the data and decides whether you are guilty or not.
HOW DOES IT TEST?
While you are asked the question the machine will check if your heart beat, perspiration and breathing levels increases or not. If it increases by a substantial level then it will be confirmed that you are lying whereas if it stays more or less the same then it means that the person is not lying or is saying the truth.
HOW RELIABLE IS IT?
The polygraph test has come under a lot of criticism because experts have said that the test doesn’t measure if a person is lying or not but measures a person stress that can be caused due to anything. It test has a huge flaw because it can be cheated easily and a trained expert can easily control their emotions and act calm to cheat the test. The test measures an arousal in emotions which can be caused be caused by stress or anxiety of the event and an innocent person can be found guilty. Unlike a fingerprint test you can’t give any concrete proof that this test is absolutely correct and will always lead to uncertain conclusions, which is not a risk most people will prefer at important judicial situations. In the past people have been known to take drugs that will calm their nerves to cheat the test.