BYPOL employee fired over lie detector but scientists say it can be fooled

Sharon Stone takes a lie detector test / Footage from the film "Basic Instinct"
Sharon Stone takes a lie detector test / Footage from the film "Basic Instinct"

The scandal of former BYPOL social media administrator Matvey Kupreichyk, who refused to take a lie detector test and was fired as someone who had "lost credibility," is simmering online. Apparently, polygraph testing is a very important procedure for former members of the security services, although researchers claim that the polygraph is imperfect and can be fooled.

Let's find out

Polygraphs work by measuring certain bodily functions, such as skin conductance, heart rate, blood pressure, and breathing. All of these responses are difficult for the mind to control, so many people believe that measuring them can reveal when someone is lying. For example, a person's blood pressure or heart rate may increase when they are being dishonest. 

 

What happens when a person takes a lie detector test?

After a person is hooked up to a polygraph, the examiner asks them questions, according to Wonderopolis. First, there are the control questions, to which the examiner knows the answers and to which honest answers, such as name and address, are certain to be given. At the same time, the respondent's bodily reactions are measured. This provides a baseline reading. The person is then asked key questions to which the examiner does not know the answers. At this point, the person's bodily reactions are also measured.

Sometimes the examiner may notice that the person begins to breathe faster while answering key questions. His or her heart may begin to beat faster. If this happens, the examiner may conclude that the person is lying.

BYPOL: сотрудника уволили из-за полиграфа. Учёные: полиграф можно обмануть
Cartoon from antipoligraph.org

How reliable are polygraph tests?

Critics of polygraphs believe that these machines are unstable and that it makes no sense to invest in their development. They say there are "too many variables involved".

Many researchers agree that polygraphs can detect lies, but the machines make mistakes. For example, people have used some strategies to fool the polygraph.

To follow important news, subscribe to the Euroradio channel on Telegram.

Every day we publish videos about life in Belarus on our YouTube channel. You can subscribe here.