The invention of the lie detector!

catching liers since 1921

When & Who

The first successful lie detector was invented in 1921 by John Larson! The first successful polygraph machine was called the breadboard polygraph. He was a California medical student and he invented the lie detector test to catch bad guys and was used in the police force since 1924.

How it works

When a person lies it creates an amount of stress that changes in several actions. A bunch of different sensors are attached to your body and when you lie the polygraph measures changes in breathing, blood pressure, pulse and perspiration then the pens on the machince record the data on a piece of graph paper.

The impact on american society

The impact that it had on the society was that it helped catch criminals and wifes trying to catch cheating husbands. Also it played a major roll in the police force not just back then but still today.

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