If you thought that this detector magically understands lies, then you were living in a lie! (ha!)

Now that I have prepared you for what is to come, it's time for THE MOMENT OF TRUTH! I hope you are ready!

The polygraph (also known as the lie detector) records different bodily reactions caused by how the examinee feels when answering certain questions.

When answering questions that he will truthfully answer (e.g. his name), he will be relaxed and there will usually be no changes in his breathing, blood pressure, etc. However, if he is asked a question that he can lie about, his body may react to it. His palms may sweat, his heart rate may increase, etc.

Generally, we may not always listen to our body, but it listens to us! For example, if I tell a lie, I feel my heart beating a little faster because my body is saying at that moment, "Hey, what are you doing there?"

But how are all these changes recorded?

Changes in breathing are measured with pneumographs wrapped around the chest!

Cardiovascular activity is evaluated thanks to a wristband!

Various stimuli are measured with electrodes connected to the fingers!

These cool little systems are connected to a needle that writes on a paper that rolls underneath it (now it can also be done electronically). When the changes in the body are small, the needle remains steady and continues in a straight line, so everything is fine!

However, large changes in the body disturb the needle and the line is no longer straight, so it tells you, "Oops, the friend got nervous here, you'll see that he told a lie." (imagine what it looks like on an electrocardiogram). SO THE POLYGRAPH IS NOT A LIE DETECTOR, BUT A FEAR/ANXIETY DETECTOR! That's why the scientific community doesn't consider it very accurate!

And let's say, for example, if I am asked what color shirt I am wearing and immediately after that if I killed the newsstand guy AND I KNOW that I am considered a suspect and MY WHOLE LIFE HANGS BY A THREAD because of this answer (even if I didn't do it), I will get anxious!

Nevertheless, in 80 countries (and to the highest degree in the USA), the polygraph is used as an interrogation tool for criminal suspects! (EVEN BY THE FBI and the CIA!)

The reason is literally that in phases where there is absolutely no evidence, "instead of playing heads or tails and leaving it to chance, it's better to use the polygraph!" (LOL)

Unfortunately, there have been many cases where criminals deceived the polygraph and got away with it (years later, evidence proving their guilt was found), as well as innocent people who fell victim to their anxiety!

Long before the polygraph, for example in the Middle Ages, the phase of lie detection was much more brutal as they tortured someone (even with boiling water!) until they gave in and told the truth! LET'S HOPE THAT THOSE TIMES REMAIN IN THE MIDDLE AGES.

Similar devices had already been developed since 1895, while in 1906 Scottish cardiologist James Mackenzie invented the first polygraph!

However, the father of the lie detector became the American psychologist and creator of comics, William Marston, around 1920!

This was the first person to find a connection between blood pressure and lying (fear and anxiety, that is).

However, the true inventor of the polygraph was his wife, Elizabeth Holoway, because she had noticed that when she got nervous, her blood pressure would rise!

FAN FACT

In 1941, Marston had the idea for a superhero who could win the battle with the power of love! So his wife says, "Okay cool, BUT FOR GOD'S SAKE NOT A WOMAN!" And that's how Wonder Woman was born!

But I don't understand why we give all the credits to Marston, when his wife, the goddess Elizabeth, thought of everything! IT'S ALL A LIE*!

Generally, if you're interested in being examined by a polygraph, it costs around $200 to $2000. We're talking about a $2 billion industry in America alone!

 SUPER COOL FACT 

The first and only time that a lie detector was used in a Greek trial was in 2002, in the case of Theodoros Kallias, who was accused of double murder! In general, this case lasted for 5 years, so they applied it as an exceptional solution and in the end, the guy was acquitted!