The Science Behind Lie Detector Tests | How Do They Do It?

Find out the history of lie detectors, and how the modern polygraph machine works to catch people lying.

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[gplgs]

“Your hands are sweaty, you’re lying”

“Sir, it’s 83 degrees in here with no air conditioning, of course my hands are gonna be sweaty”

[PatchworkRose]

I would never be able to pass a lie detector test bc of my anxiety. My heart rate would be through the roof.

[mayainverse]

the ironic thing is the most dangerous types of people can pass these things with flying colors because they don't get nervous for these kinds of things while the most good hearted people are most likely to fail. like they said in this video a serial killer passed with ease and later they pinned the crimes on an innocent guy who failed the test.

[danielas]

Some criminals are so emotionless and actually believe they didn’t do anything wrong believing their own lies and being relaxed

[aspenmangamingwt]

So they just assume that because of the blood pressure and your breathing and sweat level. So if your just nervous and you never lied they just assume you lied. BS if you ask me

[AngusWd]

Your fate is in the hands of a computer, makes me feel super safe and secure

[groundshaker]

It’s totally failed method
No accuracy at all
It’s my personal experience

[odiliamillan]

This shit is about as accurate as a toddler taking a 12 grade math test

[itzolie]

Polygraph results are not admissible in court. That should tell you all you need to know.

[queenofthenight]

Many people sweat and have a high blood pressure under pressure and they don’t have to lie.

[Ruessavel]

I love how they mention one guy back in the day who got away with a lie detector test, quickly insert that he killed 70 people, then IMMEDIATELY CUT TO THE NEXT SCENE WITH NO ELABORATION. WHAT?! WHAT DO YOU MEAN!?

[mr.benjamin]

I passed one years ago. I was guilty as sin. Just make yourself belief the lie and relax.

[johnbhai]

Funfact: The credited Inventor of Lie Detector was also the Creator of Wonder Woman... Along with the help of his wife Attorney and Psychologist Elizabeth Holloway, William Marston develop a lie detector in 1915. He was also a psychologist and took his wife as an inspiration for Womder Woman character.

[iudexe]

I mostly like to sweating bullets when my body are strapped with this machinery craps whether I'm lying or not

[jmcnutt]

I’m pretty sure anyone would have an erotic heart rate and sweaty hands even if you’re being accused of something you didn’t do

[anything.but.carrots]

My anxiety with my excessive sweating won’t let me pass through a lie detector test

[blessedfela]

I would only pass this if they did it without me knowing, otherwise once they tell me we are doing it, that would be it for me

[nextlevelangling]

Okay these things are so scientifically flawed. You’re telling me if my hands are sweaty that I’m lying?😂😂 this is so stupid they shouldn’t be used at all

[Kellypet]

Just explain it! Not everything has to be a fake reality tv show. Dun dun duuuun. No, just say it! Frick sake! This was so dirivitive!

[ToxicAvengerCleanYourMind]

Even a question can make your heart race so imagine if out in the woods someone asks you, Did you just see that bear!?.. your body would react even when telling the truth that you didn't... So if you're innocent in a murder but ask you, "Did you kill them" a lot of people would react to such a scary question and get nervous whether you did, or didn't ... Especially when beforehand they ask you softball questions like "Is the sky blue"... Plus, I bet if they ask you that most people could lie and the machine wouldn't pick it up because it's the question that would make a person nervous, not whether the lie or not.