Lie Detector

Hannah Davenport

The Lie Detector

Hannah Davenport

The History of Lie Detectors

Lie detectors have been used throughout American history even in other countries. They have evolved into machines from man made methods.

The Chinese Method

The Chinese method was one of the first lie detecting methods. In the 16th and 17th century the Chinese had the lie detecting system invented. They would put a mouthful of rice in the accused's mouth and if it was spit out wet they were being honest and if they spit it out dry they were lying.

Hugo Munsterberg

In the 1890's Hugo Munsterberg invented a new method for detecting lies. He developed the notion that raised blood pressure correlated to dishonesty.


In 1902 an inadequate lie detector test was invented by a man named James McKenzie. Later on in the 18th century, 1921, a medical student named John Larson from the University of California invented the modern polygraph instrument, which was much more accurate in its results than the previous machine.


In 1925, Leonarde Keeler, who had gained firsthand experience in polygraph interrogations while working with John A. Larson at the Berkeley Police Department, worked to create a less cumbersome polygraph instrument that used inked pens to record the relative changes in a subject's blood pressure, pulse rate and respiratory patterns.


In 1938, Leonarde Keeler further refined the instrument when he added a third physiological measuring component for the detection of deception, the psycho galvanometer: a component that measured, during questioning, changes in a subject's skin electrical resistance. In doing so, it signalled the birth of the polygraph as we know it today.

1945 to 1947

Between 1945 and 1947, John E. Reid, a lawyer from Chicago, Illinois, developed the Control Question Technique (CQT), a polygraph technique that included control questions (comparison) which were designed to be emotionally arousing for non-deceptive subjects and less emotionally arousing for deceptive subjects than the relevant questions previously used. The Reid Control Question Technique was a major breakthrough in polygraph methodology. Additionally, John E. Reid was the first examiner to use movement sensors to detect in any movement during an examination.
The lie detector overall was a great invention. With a couple of bumps in the road it turned into a great thing. It has helped police and many other people. Thanks to all of the inventors who made this invention exist we know have a trustworthy way to tell if people are being honest. In the future I'm sure there will be another way to detect lies that we won't need to have machines do it for us but until then this invention will do.