The earliest antecedents to the modern lie detector were the devices used in trial by ordeal or for torture. During the Middle Ages in Europe, torture was a practice rooted in the theory that “the body’s agony would oblige the lying mind to croak out its secret, ”according to Ken Adler, in his article, "To Tell the Truth: The Polygraph Exam and The Marketing of American Enterprise."¹  Departing from this form of lie detection in 1730, Daniel DeFoe became the first to suggest the evaluation of heart rate to detect deception.²  However, the practice of torture would have to be discredited first before a more scientific form of lie detection would emerge. Finally, in the eighteenth century, campaigns against judicial torture in Europe led to its declining use. An Italian Enlightenment thinker, Cesare Beccaria, wrote in 1764, “By this method, the robust will escape, and the feeble be condemned. These are the inconveniences of this pretended test of truth.”³ Torture as a valid method of truth telling would began to come into question during Beccaria's time. There had to be another way to tell the truth from a lie.

                The modern lie detector is a combination technology; none of the pieces were new, but it was the first time they had been used together and for this purpose. Its evolution began slowly, with the first tests to determine the physical responses of the body during the act of deception. In 1895, the so-called “ ‘Father of Modern Criminology,’” Cesare Lombroso became the first to attempt to use science to detect deception. He used a device called a plethysmograph, which was made to monitor any changes in the blood flow of a subject during interrogation.⁴  The next break-through came in 1897 when B. Sticker developed a method of measuring the galvanic responses of an individual to interrogation, in other words, the amount of sweat they produced as determined by the electric conductibility of their skin.⁵  In 1914, Vittorio Benussi began to study the breathing rates of individuals, using pneumatic tubing.⁶   Using this device, which wrapped around the subject’s chest to measure depth and rate of breath, Benussi discovered the “ratio of inspiration and expiration was generally greater before truth telling than that before lying,” as noted by Eugene Levitt in his article, "The Scientific Evaluation of the Lie Detector."⁷  This discovery by Benussi meant that not only could blood pressure, pulse rate and sweat production be linked to the act of deception, but breathing rates as well. Finally, all the pieces that make up the modern lie detector, the polygraph, had been applied to forensic science and separately tested.

     
               
            The first machine to take the name the "polygraph" was actually a copy machine invented by an Englishman named John Isaac Hawkins in 1804.⁸  The name simply means “many writings,” derived from Greek, so this early polygraph enabled the user to write with two pens, creating a duplicate copy at the same time as he created the original copy. In 1908, James MacKenzie, an English doctor, publicized his invention, the “‘ink polygraph,’” which could be used to monitor the cardiovascular responses of his patients by taking their pulse and blood pressure. ⁹