Larson Constructs the First Modern Polygraph Summary

  • Last updated on November 10, 2022

John A. Larson’s development of the first modern lie detector revolutionized the administration of criminal justice in the United States.

Summary of Event

The first attempt to utilize a scientific instrument for the purpose of lie detection occurred in 1895. Cesare Lombroso, a celebrated Italian criminologist, published an account of several experiments he had conducted on criminal suspects whose truthfulness or deception he had sought to determine. Lombroso had recorded fluctuations in the suspects’ blood pressure or pulse rates when they were questioned about the offenses under investigation. Inventions;polygraph Polygraphs Lie detectors [kw]Larson Constructs the First Modern Polygraph (1921) [kw]First Modern Polygraph, Larson Constructs the (1921) [kw]Polygraph, Larson Constructs the First Modern (1921) Inventions;polygraph Polygraphs Lie detectors [g]United States;1921: Larson Constructs the First Modern Polygraph[05260] [c]Science and technology;1921: Larson Constructs the First Modern Polygraph[05260] [c]Inventions;1921: Larson Constructs the First Modern Polygraph[05260] Larson, John A. Keeler, Leonarde Vollmer, August Lombroso, Cesare

The instrument that Lombroso used—the hydrosphygmograph Hydrosphygmograph —had been invented and developed by other scientists for medical purposes; it was not originally intended for use in detecting deception. Essentially, the instrument consisted of a small, water-filled tank into which the subject’s fist was placed. The immersed fist was then sealed into the tank by a rubber membrane. Changes in the subject’s pulse pattern and blood pressure were transferred from the fist to the water in the form of changes in water level, and this in turn caused changes in air pressure, which was registered by an air-filled tube leading to a revolving drum.

Although Lombroso reported successful results in his experiments, his research ended with the publication of his book in 1895. It was not until 1915 that any other investigator conducted further experiments in lie detection involving blood pressure changes. In that year, William Moulton Marston Marston, William Moulton undertook the study of lie detection. Marston was a student of Hugo Münsterberg, Münsterberg, Hugo a well-known pioneer in criminal psychology at Harvard University and author of On the Witness Stand (1908), On the Witness Stand (Münsterberg) in which he discussed the effects of emotional changes on blood pressure, respiration, galvanic skin response, and other physiological processes and pointed out the possibility that such reactions might be useful indicators of deception.

Marston’s technique consisted essentially of the use of an ordinary sphygmomanometer—the same type of instrument physicians use to measure patients’ blood pressure—to obtain periodic, discontinuous blood pressure readings on a subject during the course of a test. Marston also recorded data on respiration and noted the time of the subject’s verbal responses. In addition, he used a galvanometer to record skin resistance changes and a gripping device to record tension. He initially employed a questioning technique that involved an obscure word-association test, but he eventually abandoned this in favor of narrative-type answers and cross-questioning of the subject regarding his or her statements. Marston reported some very successful results with this technique.

In the early 1920’s, three members of the police department in Berkeley, California, conducted further experiments in lie detection: John A. Larson, a police officer; August Vollmer, the founder and chief of the department, which was known for its “scientific” approach; and Leonarde Keeler, a patrolman. While working under Chief Vollmer, Larson began experimenting with measurement of blood pressure and respiratory changes during the questioning of criminal suspects. Encouraged by Vollmer, Larson assembled the first continuous-recording interrogation lie detector, which he named the polygraph.

Some of the first practical applications of the device were outstandingly successful. For example, in one case, a female college student had been shoplifting in a local store, but the shop clerk could not identify her; the clerk knew only that the thief lived in a certain dormitory. Larson was able to question all thirty-eight residents of the dormitory (during sixteen hours in one day) using what later came to be known as the relevant/irrelevant, Relevant/irrelevant questioning technique or R/I, technique, in which the subject is asked a mixture of irrelevant and relevant questions. One of the young women responded much more strongly to the relevant questions than did any of the others, and she subsequently made a full confession.

Larson’s instrument used pens to record, on a moving strip of graph paper, the changes in a subject’s heart rate, blood pressure, respiration, and electrical skin reaction as the individual underwent continuous questioning. The theory behind the polygraph was that a lying subject would experience emotional and physical stress that would cause the lines on the graph to move above previously established normal levels.

After a preliminary interview, the subject was seated in a chair that was specially constructed to permit the attachment of the various measuring devices to the subject’s body. The pneumograph tube was tied to the subject’s chest, the blood pressure cuff was wrapped around the upper arm, and a net of electrodes was attached to the hands. The subject was directed to look straight ahead. The examiner was seated to one side behind a desk containing a set of controls the subject could not see. These instruments began a continuous graphic recording when the examination commenced. The questions asked were based on the results of the preliminary interview along with available facts and circumstances forming the basis of the accusation. They also varied somewhat with each person questioned.

Some of the team’s first experiments provoked severe criticism from those who did not comprehend the technique. These critics argued that tension and nervousness resulting from the mere realization that a crucial test was being performed would naturally produce false and misleading indications on the graph. The team was quick to explain, however, that testing always began with a long series of deliberately innocuous questions, or control inquiries. Not until the subject had established a normal level of graphic reactions did the examiner, with no change of voice or facial expression, introduce the crucial question that referred directly to the offense under investigation.

Although Larson is credited with the development of the modern lie detector, Keeler later introduced important refinements to Larson’s original equipment. These included, in addition to units for recording changes in blood pressure, pulse, and respiration, a galvanometer for recording galvanic skin response, or electrodermal response. Galvanic skin response is obtained through electrodes fastened to the fingertips, as the fingertips are believed to show evidence of perspiration when a person is under emotional stress.


Compared with the overwhelming enthusiasm and extravagant claims of his associates and successors, Larson’s attitude toward the polygraph’s effectiveness in detecting deception remained scientifically skeptical. During the first half century after 1915, when Marston’s “lie detector” was becoming entrenched in American criminology circles, Larson was the only investigator to undertake an objective study of the accuracy of the diagnosis of deception using polygraph recordings obtained from criminal suspects. In a 1938 paper, Larson, who eventually became a forensic psychiatrist and criminologist, reported on a study in which he examined sixty-two suspects whose records were then evaluated independently by nine psychologists. The numbers of records classified by the different judges as indicating deception ranged from five to thirty-three, although sixty-one of the suspects were, in fact, truthful.

Larson later said that although he originally hoped that instrumental lie detection would become a legitimate part of professional police science, he believed it was becoming little more than a psychological “third degree” aimed at extorting confessions—not unlike the old method of physical beatings. He even stated that at times he regretted ever participating in the development of the polygraph.

It should be emphasized that at least some of Larson’s disillusionment was related to the relevant/irrelevant test format; his statements were made before other interrogation techniques, notably the control-question lie test and the guilty knowledge test, were developed. Until about 1950, the R/I procedure was standard in the field, and for a time after that it continued to be taught in one major school of polygraphy and continued to be used by many older examiners.

Although questions about its reliability continued to be raised and debated, by the end of the twentieth century the lie detector was used in criminal investigations and in security applications in Canada, Israel, Japan, South Korea, Mexico, Pakistan, the Philippines, Taiwan, and Thailand. In North America, some employers were using the device as part of the screening process undergone by potential employees. Western European police agencies remained skeptical about the value of the polygraph.

In the early twenty-first century, experts in the field agreed that no machine can detect lying; a polygraph can only provide certain data when used with a particular form of interview or test, and trained examiners must interpret the data in reaching a diagnosis of truthful or deceptive. Several different types of lie detectors have been developed, and researchers continue to seek the most appropriate methods of interpreting (and demonstrating the reliability and validity of) the data produced by each type. Inventions;polygraph Polygraphs Lie detectors

Further Reading
  • citation-type="booksimple"

    xlink:type="simple">Block, Eugene. Lie Detectors: Their History and Use. New York: David McKay, 1977. Traces the development of lie detection techniques from ancient times to the late 1970’s. Discusses a variety of legal cases to illustrate the value, dangers, and limitations of lie detectors. Concludes with a look into the future use of the polygraph in criminal and noncriminal settings.
  • citation-type="booksimple"

    xlink:type="simple">Gale, Anthony, ed. The Polygraph Test: Lies, Truth, and Science. Newbury Park, Calif.: Sage, 1988. Excellent source of extensive information on the polygraph’s use in three contexts: criminal investigation, security screening, and personnel selection. Based on research conducted in England, but covers polygraph use in the United States and elsewhere. Includes discussion of psychological, legal, and civil rights issues associated with polygraph use. Features an annotated bibliography, a guide for students, and a glossary.
  • citation-type="booksimple"

    xlink:type="simple">Lykken, David T. A Tremor in the Blood: Uses and Abuses of the Lie Detector. 2d ed. New York: Plenum, 1998. Presents a critical appraisal of the history, theory, and practices of polygraphic interrogation. Examines the use of the polygraph from the point of view of the citizen as well as from the perspective of the “lie detector industry.”
  • citation-type="booksimple"

    xlink:type="simple">National Research Council. Committee to Review the Scientific Evidence on the Polygraph. The Polygraph and Lie Detection. Washington, D.C.: National Academies Press, 2003. Reviews research data concerning the use of the polygraph in criminal investigation, employment screening, and other applications. Examines the theory of how the instrument works as well as the accuracy of the interpretation of polygraph results. Includes extensive appendixes.
  • citation-type="booksimple"

    xlink:type="simple">Reid, John E., and Fred E. Inbau. Lie Detection and Criminal Interrogation. 3d ed. Baltimore: Williams & Wilkins, 1953. A manual not only for criminal investigators but also for those with an interest in the “art” of lie detection and criminal investigation. Discusses the methods used in the detection of deception as well as various techniques law-enforcement officials use to elicit information. Includes numerous graphs, charts, and illustrations.
  • citation-type="booksimple"

    xlink:type="simple">_______. Truth and Deception: The Polygraph (“Lie-Detector”) Technique. 2d ed. Baltimore: Williams & Wilkins, 1977. One of the best and most detailed sources of information for those interested in learning about the polygraph technique. Provides a general overview of the historical development of the instrument as well as a clear picture of how the test is administered and interpreted. Also discusses legal, moral, and philosophical issues surrounding the polygraph test. Includes graphs, appendixes, and selected bibliography.

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