Benefits and Uses of a Lie Detector

You may have seen the demonstration of lie detectors in movies. These devices are used in order to extract the truth from the lying witnesses. The wire of the devices makes a connection between the lie detector and the person being tested. The machine draws lines on the paper to help the professional determine if the person is lying or telling the truth.

According to the latest studies, the accuracy of a lie detector varies between 70% and 95%. Let’s now take a look at some of the benefits offered by this machine.

Benefits and Usage

Since lie detector tests are quite popular, more and more people are beginning to use them. Nowadays, they are being used for social research projects.

Often, lie detectors can have an impact on the way the subject gives answers to the questions. While they are not used solely to find out the truth, they do help record changes in the physiological indices of the subject. So, the experiments are done in combination with before and after interview tests.

It’s important to note that some companies also use polygraph tests. The tests are done in order to screen potential personnel.

Another common use of the devices involves the assessment of the statements given by the witnesses and suspects. Often, they are used by lawyers, police offices, and prosecutors. Moreover, law enforcement agencies also use them to monitor the post-conviction offenders. However, it’s important to note that the machines are not used to determine if the subject is really guilty.

It’s interesting to note that toy lie detectors are also quite popular among kids. Interestingly enough, these toys are based on similar algorithm and may give a mild electric shock to the subject if he tells a lie. However, it is important to remember that the results may not be accurate.

Negative Remarks

Polygraph tests are quite popular, but the results of these tests can’t be accurate. The reason is that not everyone will give the same reaction in a situation. Therefore, the physiological indices of a person may be different from another test subject. That’s the reason this device is not considered 100% reliable.

Also, polygraph tests are not worth it. The machine may give misleading results. While the authorities will be busy proving that the subject is guilty, the real culprit may go out of the reach. As a result, they have to do the test all over again, which will take a good deal of extra time.

Moreover, the tests can cost a great deal of money. Apart from the price tag of the machine, it will cost additional money to hire a qualified professional for the interpretation of the test results.


Generally, lie detector tests provide good results as far as the assessment of the subject’s honesty is concerned. So, authorities and companies can make use of them to conduct important investigations. In addition, for social events, these devices provide a good deal of entertainment. therefore, it’s safe to say that the machines are quite helpful.