History of the Polygraph
The Donkey Knows (1500-1600)
In early times, village leaders were often tasked with determining who was lying about their role in a misdeed. One method was to have the villagers enter a donkey stall and pull on the donkey's tail that had been secretly greased. Villagers were told that the donkey would only kick the guilty party. The elders would then inspect their hands after exiting the stall. If the villager claimed they pulled on the tail and didn't have greased hands, the elders believed they were guilty of the misdeed. This was an effective use of psychology and trickery as an early form of lie detection. It was not long before a more scientific form of detecting lies was invented.....the polygraph instrument.
The Kymograph (1840)
The kymograph was initially a mechanical and hydraulic device, invented by German physiologist Carl Ludwig in the 1840s, and found its first use as a means to monitor blood pressure. It basically consists of a revolving drum wrapped with a sheet of paper on which a stylus moves back and forth recording perceived changes of phenomena such as motion or pressure. It was believed that when a person fears being detected in a lie, that blood pressure variations occurred. This was the earliest form of making a permanent recording of attempts to conceal deception.
The Modern Polygraph (1992)
Today, the polygraph has been computerized and measures heart functions, breathing suppressions, electronic dermal activity, PLE and countermeasure activity, without cumbersome ink handling and endless rolls of paper. It also integrates audio and video via webcams and uses sophisticated scoring algorithms. When properly functioning and administered by a certified examiner using standardized techniques, the polygraph's accuracy is 93% to 95%. Today the polygraph is used in every western civilized country to determine veracity of truth.
Pioneers of the Polygraph
Frye vs. US (D.C. Circuit Court 1923)
This landmark case involved James Alphonso Frye, accused of robbing and murdering a doctor. Frye agreed to plea guilty to first degree murder in exchange for a dropped robbery charge. He later rescinded and went to trial for the murder, believing he could beat the charge in front of a jury. Frye's defense team introduced psychologist, Dr. William Moulton Marston, having discovered the systolic blood pressure deception test in 1915, who was eager to promote his test using the kymograph.
According to Marston, Mr. Frye's lawyers came to him and he agreed to test the defendant gratis. Marston recalled: “I gave him a deception test in the District jail. No one could have been more surprised than myself to find that Frye's final story of innocence was entirely truthful!" His confession to the Brown murder was a lie from start to finish. The judge ruled that since Marston had tested Frye prior to trial, that he could not demonstrate the kymograph in court. Ultimately, Marston's involvement in this case resulted in a jury verdict of second degree murder, which indicates substantial doubt attributed by Marston and his blood pressure instrument.
The General Acceptance Rule
Though it is believed that the Frye vs. US case decision delivered a fatal blow to the admissibility of the polygraph test in trial court, today it is allowed in 29 states under the general acceptance rule. New Mexico and Ohio allow the routine use of the polygraph. A judge can allow results from the polygraph if both the prosecution and the defense agree to the test prior to being administered, coupled with acceptance of the polygraph from the local scientific community.
The Modern Polygraph
John Augusta Larson (1892 -1965)
In 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, the kymograph. It measured the subjects pulse, blood pressure and respiratory rate, recording the information on a rotating drum of smoke paper. In 1925, Leonarde Keeler refined the instrument. Instead of using smoke paper to record changes in the suspects’ reactions, he incorporated ink pens in order to ensure the efficiency of the machine.
Leonarde Keeler (1903-1949)
Leonarde Keeler continued improving the kymograph adding skin conductance recording to the instrument. Keeler called the device he created the “Emotograph,” and he was the first American to receive a patent on what is commonly known as the polygraph—or lie detector device. He invented the analog polygraph instrument that used tracing pens on a moving chart instead of cumbersome smoke paper on a drum. Keeler went on to found a polygraph school in Chicago, the Keeler Polygraph Institute (1948). Eventually John Reid, a Los Angeles Police officer, would introduce question techniques to polygraph that are still in use today.
Cleveland Grover Backster (1924-2013)
Cleveland (Cleve) G. Backster was a student of Leonarde Keeler and a navy admiral's aide during WW2. He became the first polygraph examiner for the Central Intelligence Agency (CIA) after garnering their attention. Accordingly, he hypnotized an admiral's secretary and convinced her to give him top secret war plans. He moved on to open his own school, the Backster School of Lie Detection. He is accredited for inventing the "Zone Comparison Technique" which is a first aid technique and standardized objective scoring format used in polygraph testing. Mr. Backster is considered the father of the modern polygraph. He authored "Primary Perception," the discovery of bio communication, involving plants and human emotion.