Before modern methods, the relevant-irrelevant test defined the earliest lie detector test; this history revisits polygraphy's very first questioning format.
The Relevant-Irrelevant Test (RIT) was the first standardised polygraph questioning format, developed by John Larson at the Berkeley Police Department in 1921. This guide traces its origins, refinement by Leonarde Keeler, three decades of dominance in law enforcement, and the scientific evolution that led to today's more advanced comparison question techniques.
TL;DR — The Short Version
- The Relevant-Irrelevant Test was the first systematic polygraph questioning technique, developed by John Larson at the Berkeley Police Department in 1921 under Chief August Vollmer's leadership.
- The format alternated between relevant questions about the matter under investigation and neutral irrelevant questions, comparing physiological responses to assess truthfulness.
- Leonarde Keeler refined the technique, built portable instruments, added galvanic skin response measurement in 1938, and founded the Keeler Polygraph Institute in 1948.
- The RIT was the primary polygraph technique in law enforcement from the 1920s through the 1950s, applied in thousands of criminal investigations across the country.
- John Reid's Control Question Technique (1947) and Cleve Backster's Zone Comparison Technique (circa 1960) addressed the RIT's limitations and gradually supplanted it.
- The RIT's legacy lives on in the structural principles underlying all modern polygraph question formats, and elements persist in certain screening contexts.
Who This Guide Is For
- Polygraph students and trainees learning the historical foundations of modern testing formats
- Practising examiners who want to understand why comparison questions were developed
- Attorneys and legal professionals researching the scientific evolution of polygraph admissibility
- Criminal justice researchers studying the development of forensic interview techniques
- Anyone scheduled for a polygraph examination who wants to understand how testing methods evolved
Origins of the Relevant-Irrelevant Test
The Berkeley Police Department: Birthplace of Modern Polygraph
The Relevant-Irrelevant Test originated in one of America's most forward-thinking police departments. The Berkeley Police Department, under the leadership of Chief August Vollmer, had become the most scientifically oriented law enforcement agency in the country by the early 1920s [1]Verified August Vollmer — Wikipedia Biography
Confirms Vollmer was first Berkeley police chief, described as 'father of modern policing,' served 1909–1932. Vollmer — often described as "the father of modern policing" [2]Verified August Vollmer biography — Berkeley News / UC Berkeley
Confirms Vollmer's progressive reforms, polygraph invented by Larson at his request, first used 1921 — believed that police work should be grounded in scientific methods rather than brute force, and he actively recruited university-educated officers to implement that vision [3]Verified August Vollmer — Encyclopedia.com
Confirms Vollmer promoted fingerprinting, polygraph machines, crime laboratories, and college-educated officers.
Vollmer was the first police chief to require that officers attain college degrees, and he persuaded the University of California to teach criminal justice [2]Verified August Vollmer biography — Berkeley News / UC Berkeley
Confirms Vollmer's progressive reforms, polygraph invented by Larson at his request, first used 1921. He introduced technologies such as fingerprinting, crime laboratories, and radio communication to the Berkeley force [3]Verified August Vollmer — Encyclopedia.com
Confirms Vollmer promoted fingerprinting, polygraph machines, crime laboratories, and college-educated officers. His progressive approach created the ideal environment for the development of scientific lie detection. For a broader look at these early law enforcement innovations, see our guide on Polygraphs & Law Enforcement: Complete History (1890s–Today).
Prior to Larson's breakthrough, William Moulton Marston had developed the discontinuous systolic blood pressure test for detecting deception in 1915 [4]Verified History of Polygraph — Ohio Polygraph Services Timeline
Confirms Marston's 1915 systolic blood pressure test, Benussi's 1914 respiration research, and full polygraph development timeline. Marston's technique used a standard blood pressure cuff and stethoscope to take intermittent systolic blood pressure readings during questioning [4]Verified History of Polygraph — Ohio Polygraph Services Timeline
Confirms Marston's 1915 systolic blood pressure test, Benussi's 1914 respiration research, and full polygraph development timeline. While pioneering, it was limited to measuring a single channel using intermittent rather than continuous readings, and his questioning method was informal.
Larson's Breakthrough: Continuous Recording and Structured Questions
In 1921, John Augustus Larson — a Canadian-born medical student and police officer at the Berkeley Police Department — developed what many consider the original modern polygraph [5]Verified History of Polygraph — Polygraph and Truth Verification Services
Confirms Larson created first polygraph in 1921, Keeler added GSR in 1938, Reid developed CQT replacing RIT. Encouraged by Chief Vollmer, Larson assembled the first continuous-recording interrogation lie detector, which he named the polygraph — a word derived from the Greek meaning "many writings" [5]Verified History of Polygraph — Polygraph and Truth Verification Services
Confirms Larson created first polygraph in 1921, Keeler added GSR in 1938, Reid developed CQT replacing RIT[6]Verified John Augustus Larson — Wikipedia Biography
Confirms Larson's birth (1892), Shelburne Nova Scotia origin, Berkeley PD work, Smithsonian preservation, Britannica listing, 1965 death.
Larson's breakthrough was twofold. First, he developed an instrument (which he called the "cardio-pneumo-psychogram") that could continuously record multiple physiological channels simultaneously — blood pressure, pulse rate, and respiration [5]Verified History of Polygraph — Polygraph and Truth Verification Services
Confirms Larson created first polygraph in 1921, Keeler added GSR in 1938, Reid developed CQT replacing RIT[7]Verified Larson Constructs the First Modern Polygraph — EBSCO Research
Confirms R/I procedure was standard until about 1950, Larson's dormitory case, early successes and later disillusionment. Second, he created a structured questioning format that could be administered consistently across subjects and examiners [8]Verified Polygraph Journal (1985) — History of Lie Detection
Confirms Larson utilised the relevant/irrelevant test format and developed yes/no questioning procedure. This was the Relevant-Irrelevant Test.
The instrument recorded these responses on a revolving drum of smoked paper [5]Verified History of Polygraph — Polygraph and Truth Verification Services
Confirms Larson created first polygraph in 1921, Keeler added GSR in 1938, Reid developed CQT replacing RIT. While the San Francisco press nicknamed it "Sphyggy" because reporters couldn't pronounce "sphygmomanometer" [9]Verified John Augustus Larson — Wikipedia (Additional Details)
Confirms Larson's 'Sphyggy' nickname, Smithsonian preservation, Britannica Almanac listing, and 'Frankenstein's monster' quote, the device represented a genuine scientific leap. The first practical use came in the summer of 1921, when the San Francisco Call and Post arranged for Larson to test William Hightower, accused of murdering a priest [9]Verified John Augustus Larson — Wikipedia (Additional Details)
Confirms Larson's 'Sphyggy' nickname, Smithsonian preservation, Britannica Almanac listing, and 'Frankenstein's monster' quote.
One of the earliest notable successes involved a case at a Berkeley dormitory. Larson was able to question all thirty-eight residents using the relevant/irrelevant technique over sixteen hours in a single day to identify a shoplifter — a dramatic demonstration of the method's practical applicability [7]Verified Larson Constructs the First Modern Polygraph — EBSCO Research
Confirms R/I procedure was standard until about 1950, Larson's dormitory case, early successes and later disillusionment. For more on these early developments, see our guide on Angelo Mosso: Pioneer of Neuroscience & Polygraph Science.
The Intellectual Foundations
The RIT drew on several converging streams of scientific thought from the late nineteenth and early twentieth centuries. Italian physiologist Angelo Mosso used a plethysmograph as early as 1878 to study how emotion and fear affected cardiovascular and respiratory activity during questioning [10]Verified History of Polygraph — Cesare Lombroso and Angelo Mosso Timeline
Confirms Mosso's 1878 plethysmograph research, Lombroso's 1895 hydrosphygmograph experiments, and Keeler's 1925 ink pen innovations. Italian physician Cesare Lombroso then modified an existing hydrosphygmograph in 1895 and used it in experiments to measure physiological changes in crime suspects' blood pressure and pulse rate during police interrogations [10]Verified History of Polygraph — Cesare Lombroso and Angelo Mosso Timeline
Confirms Mosso's 1878 plethysmograph research, Lombroso's 1895 hydrosphygmograph experiments, and Keeler's 1925 ink pen innovations.
In 1914, Italian psychologist Vittorio Benussi published his findings on the respiratory symptoms of lying, discovering that deception caused detectable changes in the ratio of inhalation to exhalation time [4]Verified History of Polygraph — Ohio Polygraph Services Timeline
Confirms Marston's 1915 systolic blood pressure test, Benussi's 1914 respiration research, and full polygraph development timeline[10]Verified History of Polygraph — Cesare Lombroso and Angelo Mosso Timeline
Confirms Mosso's 1878 plethysmograph research, Lombroso's 1895 hydrosphygmograph experiments, and Keeler's 1925 ink pen innovations. Together with Marston's 1915 blood pressure work, these advances formed the scientific foundation upon which Larson built [4]Verified History of Polygraph — Ohio Polygraph Services Timeline
Confirms Marston's 1915 systolic blood pressure test, Benussi's 1914 respiration research, and full polygraph development timeline.
Max Wertheimer also made a significant and often overlooked contribution to this intellectual lineage. In 1904, Wertheimer and Julius Klein published a groundbreaking paper entitled "Psychologische Tatbestandsdiagnostik" proposing the use of word association tests to assess whether criminal suspects had committed a particular crime [11]Verified Experimental Interrogations: Tatbestandsdiagnostik — Springer Nature
Confirms Wertheimer and Klein's 1904 paper proposing word association tests for criminal investigation[12]Verified Max Wertheimer and Julius Klein — Tatbestandsdiagnostik (1904)
Confirms Wertheimer's 1904 PhD at Würzburg, publication of Psychologische Tatbestandsdiagnostik. Wertheimer's doctoral dissertation at the University of Würzburg focused on developing a lie detector for the objective study of testimony [13]Verified Max Wertheimer — Britannica Biography
Confirms Wertheimer's 1904 PhD at Würzburg involved developing a lie detector and word association method. This work established key theoretical principles about how psychological stimuli produce measurable physiological reactions — an insight that directly informed the logic of the RIT.
Carl Jung's word association tests contributed another crucial element: the idea that specific stimuli could provoke measurable reactions revealing psychological content the subject wished to conceal. Jung's experiments demonstrated that reaction times and physiological changes correlated with psychologically significant stimuli. For a deeper look at ancient and early modern approaches, visit our guide on Udo Undeutsch: Statement Reality Analysis & Lie Detection.
How the Relevant-Irrelevant Test Works
The Two Question Types
The Relevant-Irrelevant Test uses a fundamentally straightforward structure built around just two categories of questions. Relevant questions address the matter under investigation directly — for example, "Did you steal the money from the safe?" Irrelevant questions are neutral, baseline inquiries unrelated to the investigation — such as "Is your name John?" or "Are you sitting in a chair?" For a detailed explanation of how relevant questions function in modern testing, see our guide on Relevant Questions in Polygraph Testing: Complete Guide.
The examiner alternates between these two question types throughout the test. The underlying theory holds that a deceptive subject will show stronger physiological reactions to the relevant questions compared to the irrelevant ones, while a truthful subject should show relatively uniform responses across both types. This comparison of responses forms the basis for the examiner's assessment.
The Physiological Channels
Larson's original 1921 instrument recorded two primary channels simultaneously: the pneumograph component measured thoracic breathing patterns using rubber tubes placed around the chest, and the cardiosphygmograph recorded blood pressure and pulse through an arm cuff [5]Verified History of Polygraph — Polygraph and Truth Verification Services
Confirms Larson created first polygraph in 1921, Keeler added GSR in 1938, Reid developed CQT replacing RIT[7]Verified Larson Constructs the First Modern Polygraph — EBSCO Research
Confirms R/I procedure was standard until about 1950, Larson's dormitory case, early successes and later disillusionment.
The galvanic skin response (GSR) channel was added later — notably by Keeler in 1938 — measuring changes in skin conductance through electrodes placed on the fingers [14]Verified A Review of the Polygraph: History, Methodology and Current Status
Comprehensive review confirming Keeler added GSR in 1938 based on Reverend Walter G. Summers' work, and full historical overview[15]Verified Leonarde Keeler — Wikipedia Biography
Confirms Keeler's dates (1903–1949), GSR addition 1938, founding of Keeler Polygraph Institute, 1935 Portage case, and Vollmer connection. This addition created the three-channel setup that became standard for decades. Keeler's GSR innovation was based on the earlier work of Fordham University psychologist Reverend Walter G. Summers [14]Verified A Review of the Polygraph: History, Methodology and Current Status
Comprehensive review confirming Keeler added GSR in 1938 based on Reverend Walter G. Summers' work, and full historical overview.
The rationale for monitoring multiple channels was that different individuals might show their strongest deceptive reactions in different physiological systems [16]Verified Electrodermal Lability and Concealed Information Detection
Found that electrodermally labile subjects were more frequently detected, demonstrating individual differences affect detection accuracy. Some might primarily show respiratory changes when lying, while others might exhibit more pronounced cardiovascular shifts. By recording all available channels simultaneously, the examiner could capture a fuller spectrum of physiological reactivity. Research by Waid and Orne (1980) confirmed that individual differences in physiological reactivity — specifically electrodermal lability — significantly affect detection accuracy [17]Verified Electrodermal Lability and Concealed Information Detection
Confirms individual differences in physiological reactivity affect CIT accuracy, supporting rationale for multi-channel recording. To understand the physiology behind these responses, visit our guide on Fight-or-Flight Response & Polygraph Testing: Science Guide.
The Core Limitation
The RIT's fundamental weakness lies in its lack of a proper comparison baseline. In particular, studies have indicated that "many innocent subjects exert a heightened physiological reaction to the crime-relevant questions" [18]Verified Polygraph — Wikipedia (Accuracy and Legal Status)
Confirms 1983 OTA report findings, NAS 2003 report conclusions, and that RIT produces heightened reactions in innocent subjects — not because they are lying, but because the relevant questions are inherently more emotionally significant or anxiety-provoking than neutral questions like "Is today Tuesday?"
A truthful subject may exhibit arousal to relevant questions simply as a result of recognising the importance of the question [19]Verified The Polygraph Technique Part I: Theory — John E. Reid and Associates
Confirms truthful subjects may exhibit arousal to relevant questions due to importance recognition, and Reid developed CQT in the 1940s. This means the RIT can produce false positive results — identifying innocent people as deceptive — at unacceptably high rates. This core limitation was the primary driver behind the development of comparison question techniques that would eventually supplant the RIT.
John Larson: The Man Behind the Method
Early Life and Education
John Augustus Larson (11 December 1892 – 1 October 1965) was born in Shelburne, Nova Scotia, Canada, to Swedish parents [9]Verified John Augustus Larson — Wikipedia (Additional Details)
Confirms Larson's 'Sphyggy' nickname, Smithsonian preservation, Britannica Almanac listing, and 'Frankenstein's monster' quote. His family moved to New England during his early childhood. He studied biology at Boston University, supporting himself with odd jobs ranging from busboy and paperboy to stonecutter and elevator operator [9]Verified John Augustus Larson — Wikipedia (Additional Details)
Confirms Larson's 'Sphyggy' nickname, Smithsonian preservation, Britannica Almanac listing, and 'Frankenstein's monster' quote. In 1915, he earned a master's degree with a thesis on fingerprint identification — work that inspired his interest in forensic science [9]Verified John Augustus Larson — Wikipedia (Additional Details)
Confirms Larson's 'Sphyggy' nickname, Smithsonian preservation, Britannica Almanac listing, and 'Frankenstein's monster' quote.
This led him to the University of California, Berkeley, where he obtained a Ph.D. in physiology [9]Verified John Augustus Larson — Wikipedia (Additional Details)
Confirms Larson's 'Sphyggy' nickname, Smithsonian preservation, Britannica Almanac listing, and 'Frankenstein's monster' quote. He became the first American police officer with an academic doctorate [9]Verified John Augustus Larson — Wikipedia (Additional Details)
Confirms Larson's 'Sphyggy' nickname, Smithsonian preservation, Britannica Almanac listing, and 'Frankenstein's monster' quote, joining the Berkeley Police Department where his scientific background would intersect with Chief Vollmer's progressive vision for law enforcement.
Polygraph Development and the College Hall Case
Working under Chief Vollmer's encouragement, Larson began experimenting with measuring blood pressure and respiratory changes during the questioning of criminal suspects [7]Verified Larson Constructs the First Modern Polygraph — EBSCO Research
Confirms R/I procedure was standard until about 1950, Larson's dormitory case, early successes and later disillusionment. By the spring of 1921, he unveiled his cardio-pneumo-psychogram [7]Verified Larson Constructs the First Modern Polygraph — EBSCO Research
Confirms R/I procedure was standard until about 1950, Larson's dormitory case, early successes and later disillusionment. The instrument was subsequently used in dozens of investigations, including the famous College Hall dormitory case at Berkeley where thefts had been occurring among female students [7]Verified Larson Constructs the First Modern Polygraph — EBSCO Research
Confirms R/I procedure was standard until about 1950, Larson's dormitory case, early successes and later disillusionment.
Larson applied what would come to be known as the relevant/irrelevant questioning format in these early investigations [8]Verified Polygraph Journal (1985) — History of Lie Detection
Confirms Larson utilised the relevant/irrelevant test format and developed yes/no questioning procedure. His 1932 book, "Lying and Its Detection: A Study of Deception and Deception Tests," became the first comprehensive polygraph textbook [20]Verified Lying and Its Detection: A Study of Deception and Deception Tests (Larson, 1932)
Confirms Larson's 1932 book as referenced by the Smithsonian alongside the original instrument. During the first half century after Marston's 1915 work, Larson was the only investigator to undertake an objective study of the accuracy of deception diagnosis using polygraph recordings from criminal suspects [7]Verified Larson Constructs the First Modern Polygraph — EBSCO Research
Confirms R/I procedure was standard until about 1950, Larson's dormitory case, early successes and later disillusionment.
Legacy and the Smithsonian
Larson's original polygraph instrument is now preserved at the Smithsonian Institution's National Museum of American History in Washington, D.C. [9]Verified John Augustus Larson — Wikipedia (Additional Details)
Confirms Larson's 'Sphyggy' nickname, Smithsonian preservation, Britannica Almanac listing, and 'Frankenstein's monster' quote[21]Verified Smithsonian Magazine — Why the Creator of the First 'Lie Detector' Regretted His Invention
Confirms Larson's polygraph is at the Smithsonian, donated by Berkeley PD in 1976, Frye ruling in 1923. In 1976, the Berkeley Police Department donated it to the Smithsonian, where it has been conserved and displayed as a significant artefact in the history of American forensic science [21]Verified Smithsonian Magazine — Why the Creator of the First 'Lie Detector' Regretted His Invention
Confirms Larson's polygraph is at the Smithsonian, donated by Berkeley PD in 1976, Frye ruling in 1923. The polygraph is also included in the Encyclopaedia Britannica Almanac 2003's list of 325 greatest inventions [9]Verified John Augustus Larson — Wikipedia (Additional Details)
Confirms Larson's 'Sphyggy' nickname, Smithsonian preservation, Britannica Almanac listing, and 'Frankenstein's monster' quote.
Larson maintained a scientifically cautious attitude toward the polygraph's effectiveness throughout his career [7]Verified Larson Constructs the First Modern Polygraph — EBSCO Research
Confirms R/I procedure was standard until about 1950, Larson's dormitory case, early successes and later disillusionment. He wrote in 1965 that "this scientific investigation became for practical purposes a Frankenstein's monster, which I have spent over 40 years in combating" [9]Verified John Augustus Larson — Wikipedia (Additional Details)
Confirms Larson's 'Sphyggy' nickname, Smithsonian preservation, Britannica Almanac listing, and 'Frankenstein's monster' quote. It is important to note that much of Larson's disillusionment was specifically related to the relevant/irrelevant test format and predated the development of more sophisticated questioning techniques [7]Verified Larson Constructs the First Modern Polygraph — EBSCO Research
Confirms R/I procedure was standard until about 1950, Larson's dormitory case, early successes and later disillusionment.
Leonarde Keeler: Refining and Commercialising the RIT
From Berkeley High School to the Crime Lab
Leonarde Keeler (30 October 1903 – 20 September 1949) was born in North Berkeley, California, the son of author and naturalist Charles Keeler [22]Verified Leonarde Keeler — Wikipedia (Portage Case and Career)
Confirms Feb 2, 1935 Portage Wisconsin case, conviction of two men for assault using polygraph evidence. Named after the polymath Leonardo da Vinci and preferring to be called "Nard," Keeler was captivated by Larson's cardio-pneumo-psychogram while still a high school student working for Chief Vollmer's Berkeley Police Department [22]Verified Leonarde Keeler — Wikipedia (Portage Case and Career)
Confirms Feb 2, 1935 Portage Wisconsin case, conviction of two men for assault using polygraph evidence. For the full story of Keeler's remarkable career, see our guide on Keeler's Chicago Crime Lab: How Polygraph Went Mainstream.
After graduating from high school, Keeler enrolled at the University of California, Berkeley in the fall of 1923, later following Vollmer to UCLA when the chief briefly took charge of the Los Angeles Police Department [22]Verified Leonarde Keeler — Wikipedia (Portage Case and Career)
Confirms Feb 2, 1935 Portage Wisconsin case, conviction of two men for assault using polygraph evidence. Keeler was responsible for making the polygraph apparatus portable — a seemingly simple innovation that made the instrument dramatically more practical for field use [14]Verified A Review of the Polygraph: History, Methodology and Current Status
Comprehensive review confirming Keeler added GSR in 1938 based on Reverend Walter G. Summers' work, and full historical overview. In 1925, he devised a polygraph that used inked pens for recording physiological changes, eliminating the need for smoking paper and shellac preservation [10]Verified History of Polygraph — Cesare Lombroso and Angelo Mosso Timeline
Confirms Mosso's 1878 plethysmograph research, Lombroso's 1895 hydrosphygmograph experiments, and Keeler's 1925 ink pen innovations.
The Three-Channel Polygraph and the Portage Case
In 1930, Keeler moved to Chicago to work at the Scientific Crime Detection Laboratory at Northwestern University, ultimately becoming head of the laboratory in 1936 [22]Verified Leonarde Keeler — Wikipedia (Portage Case and Career)
Confirms Feb 2, 1935 Portage Wisconsin case, conviction of two men for assault using polygraph evidence[23]Verified Scientific Crime Detection Laboratory at Northwestern — Reid Technique Wikipedia
Confirms SCDL established in 1929, both Keeler and Reid set up polygraph training clinics in Chicago. The lab had been established in 1929 to better combat crime in the wake of the St. Valentine's Day Massacre [23]Verified Scientific Crime Detection Laboratory at Northwestern — Reid Technique Wikipedia
Confirms SCDL established in 1929, both Keeler and Reid set up polygraph training clinics in Chicago.
In 1938, Keeler added the psychogalvanometer — measuring galvanic skin response (GSR) — creating the three-channel polygraph that became the field's standard for decades [14]Verified A Review of the Polygraph: History, Methodology and Current Status
Comprehensive review confirming Keeler added GSR in 1938 based on Reverend Walter G. Summers' work, and full historical overview[15]Verified Leonarde Keeler — Wikipedia Biography
Confirms Keeler's dates (1903–1949), GSR addition 1938, founding of Keeler Polygraph Institute, 1935 Portage case, and Vollmer connection. This enhancement measured changes in electrical conductance of the skin to detect emotional arousal. In 1939, Keeler patented what is now understood as the prototype of the modern polygraph [15]Verified Leonarde Keeler — Wikipedia Biography
Confirms Keeler's dates (1903–1949), GSR addition 1938, founding of Keeler Polygraph Institute, 1935 Portage case, and Vollmer connection.
On 2 February 1935, Keeler achieved a landmark moment when his Keeler Polygraph was used for the first time in a criminal trial in Portage, Wisconsin [22]Verified Leonarde Keeler — Wikipedia (Portage Case and Career)
Confirms Feb 2, 1935 Portage Wisconsin case, conviction of two men for assault using polygraph evidence[24]Verified Harvard Center for Law, Brain & Behavior — Will Lie Detectors Get Their Day in Court Again?
Confirms Grignano and Loniello trial details, Feb 2 1935 date, and circumstances of Portage case. He tested two men, Tony Grignano and Cecil Loniello, who were accused of attempting to kill a sheriff [24]Verified Harvard Center for Law, Brain & Behavior — Will Lie Detectors Get Their Day in Court Again?
Confirms Grignano and Loniello trial details, Feb 2 1935 date, and circumstances of Portage case. Both failed the test, and the polygraph results were admitted as evidence — the first time this occurred in a court case — contributing to their conviction for assault [22]Verified Leonarde Keeler — Wikipedia (Portage Case and Career)
Confirms Feb 2, 1935 Portage Wisconsin case, conviction of two men for assault using polygraph evidence[24]Verified Harvard Center for Law, Brain & Behavior — Will Lie Detectors Get Their Day in Court Again?
Confirms Grignano and Loniello trial details, Feb 2 1935 date, and circumstances of Portage case. For more on how polygraph instrumentation has evolved since Keeler's era, see Axciton Systems History: Pioneering Computerized Polygraph and The Stoelting Company: 140 Years of Polygraph Innovation.
The Keeler Polygraph Institute
In 1948, Keeler founded the world's first polygraph school — the Keeler Polygraph Institute — in Chicago, Illinois [10]Verified History of Polygraph — Cesare Lombroso and Angelo Mosso Timeline
Confirms Mosso's 1878 plethysmograph research, Lombroso's 1895 hydrosphygmograph experiments, and Keeler's 1925 ink pen innovations[22]Verified Leonarde Keeler — Wikipedia (Portage Case and Career)
Confirms Feb 2, 1935 Portage Wisconsin case, conviction of two men for assault using polygraph evidence. This establishment formalised polygraph training and marked the profession's transition from an experimental technique to an established practice requiring specialised education. Keeler conducted intensive two-week courses in polygraph operation, followed by six-month field trials [25]Verified Leonarde Keeler — Grokipedia (Testing Statistics)
Confirms approximately 4,000 suspects tested at Berkeley PD starting 1921, LAPD tested 500+ by 1924, training programmes in Illinois.
Keeler also appeared as himself in the 1948 film noir docudrama "Call Northside 777" starring James Stewart [22]Verified Leonarde Keeler — Wikipedia (Portage Case and Career)
Confirms Feb 2, 1935 Portage Wisconsin case, conviction of two men for assault using polygraph evidence, demonstrating the degree to which the polygraph had captured the American public imagination. Tragically, Keeler died on 20 September 1949 in Door County, Wisconsin, at the age of 45, after suffering a stroke [22]Verified Leonarde Keeler — Wikipedia (Portage Case and Career)
Confirms Feb 2, 1935 Portage Wisconsin case, conviction of two men for assault using polygraph evidence. Despite his early death, Keeler's contributions to making polygraph testing practical, portable, and professionally structured remain foundational to the field.
Three Decades of Dominance: 1921–1950s
The RIT in Law Enforcement Practice
From 1921 through approximately 1950, the relevant/irrelevant procedure was the standard technique in the polygraph field [7]Verified Larson Constructs the First Modern Polygraph — EBSCO Research
Confirms R/I procedure was standard until about 1950, Larson's dormitory case, early successes and later disillusionment. In the Berkeley Police Department alone, approximately 4,000 criminal suspects underwent testing starting in 1921 [25]Verified Leonarde Keeler — Grokipedia (Testing Statistics)
Confirms approximately 4,000 suspects tested at Berkeley PD starting 1921, LAPD tested 500+ by 1924, training programmes in Illinois. By 1924, the Los Angeles Police Department had tested over 500 suspects using early versions of the device [25]Verified Leonarde Keeler — Grokipedia (Testing Statistics)
Confirms approximately 4,000 suspects tested at Berkeley PD starting 1921, LAPD tested 500+ by 1924, training programmes in Illinois.
Keeler's relocation to Chicago in 1930 accelerated adoption by establishing training programmes for police operators. He equipped officers from departments including Chicago, Elgin, Evanston, and Wheaton in Illinois to integrate polygraph testing into their investigations [25]Verified Leonarde Keeler — Grokipedia (Testing Statistics)
Confirms approximately 4,000 suspects tested at Berkeley PD starting 1921, LAPD tested 500+ by 1924, training programmes in Illinois. For a broader historical perspective on how polygraph testing became embedded in American law enforcement, see Polygraphs & Law Enforcement: Complete History (1890s–Today).
The RIT format was well-suited to the practical needs of police investigators: it was simple to administer, easy to learn, and produced clear physiological charts that examiners could interpret on the spot. These qualities helped the polygraph gain rapid acceptance among law enforcement agencies even as courts remained more cautious.
Legal Milestones and Challenges
The polygraph's legal history during this period was marked by both breakthroughs and setbacks. As early as 1923, the U.S. Court of Appeals for the District of Columbia ruled polygraph results inadmissible at trial in the Frye v. United States decision because the tests were not widely accepted by relevant experts [21]Verified Smithsonian Magazine — Why the Creator of the First 'Lie Detector' Regretted His Invention
Confirms Larson's polygraph is at the Smithsonian, donated by Berkeley PD in 1976, Frye ruling in 1923. This ruling established the "general acceptance" standard that would govern scientific evidence for decades.
Despite the Frye ruling, the 1935 Portage, Wisconsin case demonstrated that polygraph evidence could be admitted under specific circumstances — in that case, when both parties agreed to allow it [24]Verified Harvard Center for Law, Brain & Behavior — Will Lie Detectors Get Their Day in Court Again?
Confirms Grignano and Loniello trial details, Feb 2 1935 date, and circumstances of Portage case. The Keeler Polygraph had also been a showpiece at the 1933 Chicago World's Fair, raising public awareness and generating widespread interest [24]Verified Harvard Center for Law, Brain & Behavior — Will Lie Detectors Get Their Day in Court Again?
Confirms Grignano and Loniello trial details, Feb 2 1935 date, and circumstances of Portage case.
These early legal developments continue to shape polygraph admissibility today. For a comparative international perspective, see our guide on R. v. Béland: The Case That Shaped Polygraph Law in Canada.
Scientific Evaluation and the Evolution Beyond the RIT
Identifying the RIT's Weaknesses
As polygraph use expanded throughout the mid-twentieth century, researchers began to identify fundamental limitations in the relevant-irrelevant format. The core problem was simple but significant: relevant questions about a crime are inherently more emotionally arousing than neutral questions, even for innocent subjects. A truthful subject may exhibit autonomic arousal to a question like "Did you steal the money?" simply because the question relates to a serious matter with real consequences for them [19]Verified The Polygraph Technique Part I: Theory — John E. Reid and Associates
Confirms truthful subjects may exhibit arousal to relevant questions due to importance recognition, and Reid developed CQT in the 1940s.
This meant that the RIT lacked an adequate baseline for distinguishing the physiological arousal caused by deception from the arousal caused by the general anxiety of being questioned about a crime. As a result, the technique was vulnerable to producing false positives — incorrectly identifying truthful individuals as deceptive. Understanding what can affect test outcomes is valuable for anyone facing an examination; see our guide on What Disqualifies You from a Polygraph Test? Full Guide.
The 1983 OTA Report and Ongoing Research
In 1983, the U.S. Congress Office of Technology Assessment (OTA) published a landmark review of polygraph validity that found "there is at present only limited scientific evidence for establishing the validity of polygraph testing" [18]Verified Polygraph — Wikipedia (Accuracy and Legal Status)
Confirms 1983 OTA report findings, NAS 2003 report conclusions, and that RIT produces heightened reactions in innocent subjects. The report noted that even where polygraph testing detected deceptive subjects better than chance, significant error rates were possible [18]Verified Polygraph — Wikipedia (Accuracy and Legal Status)
Confirms 1983 OTA report findings, NAS 2003 report conclusions, and that RIT produces heightened reactions in innocent subjects.
Two decades later, the National Academy of Sciences (NAS) issued its comprehensive 2003 report, "The Polygraph and Lie Detection" [26]Verified The Polygraph and Lie Detection — National Academy of Sciences (2003)
Confirms APA-cited accuracy rates of 80–98% from studies since 1980, and comprehensive review of polygraph science. The American Polygraph Association cited research studies published since 1980 reporting average accuracy rates ranging from 80 to 98 percent [26]Verified The Polygraph and Lie Detection — National Academy of Sciences (2003)
Confirms APA-cited accuracy rates of 80–98% from studies since 1980, and comprehensive review of polygraph science. Polygraph proponents argued that the CQT achieved 90% or better accuracy [27]Verified Current Status of Forensic Lie Detection with the CQT — Iacono & Ben-Shakhar (2019)
Confirms polygraph proponents argue CQT has 90% or better accuracy, reviews literature since 2003 NAS report. These findings, while debated, underscored that the profession had made significant strides in improving accuracy since the RIT era — largely by adopting comparison question methods that provided better physiological baselines.
The Rise of Modern Comparison Techniques
John Reid's Control Question Technique (1947)
The most significant methodological leap beyond the RIT came in 1947, when John E. Reid — a Chicago lawyer and polygraph expert who had worked at the Scientific Crime Detection Laboratory — developed the Control Question Technique (CQT) [28]Verified Reid Method: Developing Probable Lie Comparison Questions — OJP
Confirms probable lie comparison question developed by John Reid in 1947, considered one of most significant polygraph developments[29]Verified Reid's Original 1947 Paper — Journal of Criminal Law and Criminology
Confirms Reid published 'A Revised Questioning Technique in Lie-Detection Tests' in 1947 JCLC, introducing comparative response and guilt complex questions. Reid published his innovation in the Journal of Criminal Law and Criminology as "A Revised Questioning Technique in Lie-Detection Tests" [30]Verified John E. Reid's Control Question Technique — Polygraph UK Timeline
Confirms Reid developed CQT in 1947, Backster developed ZCT with numerical scoring, and full modern era timeline.
The probable lie comparison (PLC) question, the centrepiece of Reid's innovation, was a question regarding a past act of wrongdoing of the same general nature as the incident under investigation — one to which the subject would probably lie or be uncertain about the accuracy of their answer [28]Verified Reid Method: Developing Probable Lie Comparison Questions — OJP
Confirms probable lie comparison question developed by John Reid in 1947, considered one of most significant polygraph developments. This provided a meaningful physiological baseline. A truthful subject, whose strongest emotional response would be to the comparison questions rather than the relevant questions, could be more reliably distinguished from a deceptive subject whose responses would concentrate on the crime-relevant questions.
Reid's CQT replaced the Relevant/Irrelevant Question Technique as the most widely used approach and remains so to date [29]Verified Reid's Original 1947 Paper — Journal of Criminal Law and Criminology
Confirms Reid published 'A Revised Questioning Technique in Lie-Detection Tests' in 1947 JCLC, introducing comparative response and guilt complex questions. For an in-depth exploration of modern comparison techniques, see our guide on the Utah Zone Comparison Test (UZCT): Complete Guide.
Cleve Backster's Zone Comparison Technique (c. 1960)
Building upon Reid's Control Question Technique, Cleve Backster developed the Zone Comparison Technique (ZCT) circa 1960 [31]Verified Cleve Backster Zone Comparison Technique — AntiPolygraph.org Obituary
Confirms Backster developed numerical scoring and ZCT circa 1960, widely adopted including at NCCA[32]Verified Backster Zone Comparison Technique — DACA Training Document
Confirms Backster published Zone Comparison Technique in 1960, adopted by USAMPS in 1961. A former CIA interrogation specialist, Backster divided the polygraph examination into three zones — relevant, probable-lie comparison, and neutral control — to systematically compare physiological responses [33]Verified Cleve Backster — Grokipedia
Confirms Backster introduced ZCT with three zones circa 1961, and numerical scoring systems for chart analysis in 1959.
Perhaps more significantly, Backster introduced a numerical quantification system for chart analysis, making polygraph interpretation more objective and scientific than the subjective assessments that had characterised earlier practice [31]Verified Cleve Backster Zone Comparison Technique — AntiPolygraph.org Obituary
Confirms Backster developed numerical scoring and ZCT circa 1960, widely adopted including at NCCA[32]Verified Backster Zone Comparison Technique — DACA Training Document
Confirms Backster published Zone Comparison Technique in 1960, adopted by USAMPS in 1961. This system for numerical evaluation of physiological data collected from polygraph charts became the standard procedure in the field and remains widely adopted today [31]Verified Cleve Backster Zone Comparison Technique — AntiPolygraph.org Obituary
Confirms Backster developed numerical scoring and ZCT circa 1960, widely adopted including at NCCA. Variations of Backster's ZCT are still commonly taught at polygraph schools, including the U.S. government's National Center for Credibility Assessment [32]Verified Backster Zone Comparison Technique — DACA Training Document
Confirms Backster published Zone Comparison Technique in 1960, adopted by USAMPS in 1961.
To understand how the role of the examiner has evolved alongside these techniques, see The Role of the Polygraph Examiner in a Lie Detector Test.
The Concealed Information Test: An Alternative Paradigm
In 1959, psychologist David Lykken introduced the Guilty Knowledge Test (GKT), now more commonly known as the Concealed Information Test (CIT) [34]Verified The GSR in the Detection of Guilt — David T. Lykken (1959)
Confirms Lykken's 1959 publication introducing the Guilty Knowledge Test as a psychophysiological method. Rather than attempting to detect deception directly, the CIT assesses whether a subject possesses specific knowledge about a crime that only the perpetrator would have. Published as "The GSR in the Detection of Guilt" in the Journal of Applied Psychology, this approach represented a fundamentally different theoretical paradigm from both the RIT and the CQT [34]Verified The GSR in the Detection of Guilt — David T. Lykken (1959)
Confirms Lykken's 1959 publication introducing the Guilty Knowledge Test as a psychophysiological method.
Research has demonstrated that the CIT maintains an extremely low false positive rate of approximately 5% across studies [35]Verified Current Research and Potential Applications of the Concealed Information Test: An Overview
Comprehensive overview confirming CIT's false positive rate remains extremely low (~5%) across studies, making it a particularly valuable tool when protecting innocent subjects is paramount. Japan has adopted the CIT as a routine operational method in criminal investigations involving murder, arson, and theft [36]Verified Practical Use of the Concealed Information Test for Criminal Investigation in Japan
Documents Japan's routine operational use of the CIT in criminal investigations involving murder, arson, and theft. More recent advances include P300-based brain-wave versions of the CIT, with meta-analysis finding a large mean effect size of 1.59 across 54 experimental studies [37]Verified Decoding Deception with the P300: A Meta-Analysis of the Concealed Information Test
Found large mean effect size of 1.59 for P300-based CIT across 54 experimental studies.
Research has also shown that central crime details produce stronger physiological responses than peripheral details in CIT applications, with important implications for real-world use [38]Verified Psychophysiological and Behavioral Measures for Detecting Concealed Information
Found central crime details produced stronger physiological responses than peripheral details in CIT. For comprehensive coverage of CIT research, the edited volume by Verschuere, Ben-Shakhar, and Meijer (2011) covers theoretical foundations, laboratory research, field applications in Japan, countermeasures, and legal issues [39]Verified Memory Detection: Theory and Application of the Concealed Information Test
Comprehensive edited volume covering theoretical foundations, laboratory research, field applications, countermeasures, and legal issues.
Where the RIT Survives Today
Screening Applications and Modern Relevance
Although the RIT has been largely supplanted by comparison question techniques for diagnostic testing, elements of the format persist in certain screening contexts. The U.S. National Security Agency and other intelligence agencies have employed RIT-based screening protocols, though these applications remain classified and details are limited [26]Verified The Polygraph and Lie Detection — National Academy of Sciences (2003)
Confirms APA-cited accuracy rates of 80–98% from studies since 1980, and comprehensive review of polygraph science.
The RIT's simplicity also means it continues to appear in some training curricula as a foundation upon which students learn the principles of structured polygraph questioning before advancing to more sophisticated techniques. Understanding the RIT's structure and limitations provides essential context for appreciating why comparison questions represent such a significant advancement.
For even a time after the 1950s, the RIT continued to be taught in at least one major school of polygraphy and used by many experienced examiners [7]Verified Larson Constructs the First Modern Polygraph — EBSCO Research
Confirms R/I procedure was standard until about 1950, Larson's dormitory case, early successes and later disillusionment. Today, professional organisations like the American Polygraph Association recommend validated comparison question techniques as the standard of practice.
The RIT's Enduring Legacy
The Relevant-Irrelevant Test's greatest contribution may be its structural principles rather than its specific methodology. The concept that structured questioning formats, administered consistently across subjects and scored against physiological baselines, could provide meaningful forensic information was revolutionary in 1921. Every modern polygraph technique — from the CQT to the ZCT to the CIT — builds upon this foundational insight.
Larson's work established polygraph testing as a profession requiring standardised procedures, trained examiners, and scientific instrumentation. Keeler's refinements demonstrated that the technology could be made practical enough for widespread law enforcement adoption. Together, their contributions during the RIT era created the infrastructure and professional culture that made subsequent innovations possible.
The evolution from RIT to modern techniques demonstrates healthy scientific progress. Early methods are tested, their limitations identified, and improved approaches developed — exactly the kind of iterative refinement that characterises legitimate scientific endeavour. For anyone seeking a professional polygraph examination today, the techniques used have benefited enormously from over a century of this continuous improvement. For pre-employment applications of modern techniques, see our guides on Secret Service Polygraph: Protection Detail Screening and Indiana Law Enforcement Polygraph: Pre-Employment Guide.
Frequently Asked Questions
What is the Relevant-Irrelevant Test in polygraph testing?
The Relevant-Irrelevant Test (RIT) was the first standardised polygraph questioning format, developed by John Larson at the Berkeley Police Department in 1921 [5]Verified History of Polygraph — Polygraph and Truth Verification Services
Confirms Larson created first polygraph in 1921, Keeler added GSR in 1938, Reid developed CQT replacing RIT. It alternates between relevant questions about the matter under investigation and neutral irrelevant questions, then compares the physiological responses to each type to assess whether the subject is being deceptive. While groundbreaking in its time, the RIT has been largely replaced by comparison question techniques that provide more reliable physiological baselines.
Who invented the Relevant-Irrelevant Test?
John Augustus Larson (1892–1965), a Canadian-born medical student and police officer at the Berkeley Police Department, developed the RIT in 1921 [5]Verified History of Polygraph — Polygraph and Truth Verification Services
Confirms Larson created first polygraph in 1921, Keeler added GSR in 1938, Reid developed CQT replacing RIT[9]Verified John Augustus Larson — Wikipedia (Additional Details)
Confirms Larson's 'Sphyggy' nickname, Smithsonian preservation, Britannica Almanac listing, and 'Frankenstein's monster' quote. Working under Chief August Vollmer's encouragement, Larson created both the first continuous-recording polygraph instrument and the structured relevant-irrelevant questioning format. He was the first American police officer to hold an academic doctorate [9]Verified John Augustus Larson — Wikipedia (Additional Details)
Confirms Larson's 'Sphyggy' nickname, Smithsonian preservation, Britannica Almanac listing, and 'Frankenstein's monster' quote.
Why was the Relevant-Irrelevant Test replaced?
The RIT was replaced primarily because it lacks a proper comparison baseline. Innocent subjects often show heightened physiological reactions to crime-relevant questions simply because those questions are inherently more emotionally significant than neutral ones [19]Verified The Polygraph Technique Part I: Theory — John E. Reid and Associates
Confirms truthful subjects may exhibit arousal to relevant questions due to importance recognition, and Reid developed CQT in the 1940s. This led to unacceptable false positive rates. John Reid's Control Question Technique (1947) addressed this by adding comparison questions that provide a meaningful physiological baseline against which relevant question responses can be measured [28]Verified Reid Method: Developing Probable Lie Comparison Questions — OJP
Confirms probable lie comparison question developed by John Reid in 1947, considered one of most significant polygraph developments.
When was the Keeler Polygraph first used in court?
On 2 February 1935, Leonarde Keeler used his polygraph for the first time in a criminal trial in Portage, Wisconsin [22]Verified Leonarde Keeler — Wikipedia (Portage Case and Career)
Confirms Feb 2, 1935 Portage Wisconsin case, conviction of two men for assault using polygraph evidence[24]Verified Harvard Center for Law, Brain & Behavior — Will Lie Detectors Get Their Day in Court Again?
Confirms Grignano and Loniello trial details, Feb 2 1935 date, and circumstances of Portage case. He tested Tony Grignano and Cecil Loniello, who were accused of attempting to kill a sheriff. Both men failed the test, and the polygraph results were admitted as evidence — contributing to their conviction for assault. This landmark case was the first time polygraph evidence was successfully used in a legal proceeding [24]Verified Harvard Center for Law, Brain & Behavior — Will Lie Detectors Get Their Day in Court Again?
Confirms Grignano and Loniello trial details, Feb 2 1935 date, and circumstances of Portage case.
What did Leonarde Keeler add to the polygraph?
Keeler made several crucial contributions. He made the polygraph apparatus portable for field use. In 1925, he devised a version using inked pens for recording, eliminating the need for smoking paper [10]Verified History of Polygraph — Cesare Lombroso and Angelo Mosso Timeline
Confirms Mosso's 1878 plethysmograph research, Lombroso's 1895 hydrosphygmograph experiments, and Keeler's 1925 ink pen innovations. In 1938, he added the psychogalvanometer (GSR channel) measuring galvanic skin response, creating the three-channel polygraph that became the field standard [14]Verified A Review of the Polygraph: History, Methodology and Current Status
Comprehensive review confirming Keeler added GSR in 1938 based on Reverend Walter G. Summers' work, and full historical overview[15]Verified Leonarde Keeler — Wikipedia Biography
Confirms Keeler's dates (1903–1949), GSR addition 1938, founding of Keeler Polygraph Institute, 1935 Portage case, and Vollmer connection. He patented the modern polygraph prototype in 1939 and founded the Keeler Polygraph Institute — the world's first polygraph school — in 1948 [10]Verified History of Polygraph — Cesare Lombroso and Angelo Mosso Timeline
Confirms Mosso's 1878 plethysmograph research, Lombroso's 1895 hydrosphygmograph experiments, and Keeler's 1925 ink pen innovations[22]Verified Leonarde Keeler — Wikipedia (Portage Case and Career)
Confirms Feb 2, 1935 Portage Wisconsin case, conviction of two men for assault using polygraph evidence.
Where is Larson's original polygraph instrument today?
Larson's original polygraph instrument is preserved at the Smithsonian Institution's National Museum of American History in Washington, D.C. [9]Verified John Augustus Larson — Wikipedia (Additional Details)
Confirms Larson's 'Sphyggy' nickname, Smithsonian preservation, Britannica Almanac listing, and 'Frankenstein's monster' quote[21]Verified Smithsonian Magazine — Why the Creator of the First 'Lie Detector' Regretted His Invention
Confirms Larson's polygraph is at the Smithsonian, donated by Berkeley PD in 1976, Frye ruling in 1923. The Berkeley Police Department donated it to the Smithsonian in 1976 [21]Verified Smithsonian Magazine — Why the Creator of the First 'Lie Detector' Regretted His Invention
Confirms Larson's polygraph is at the Smithsonian, donated by Berkeley PD in 1976, Frye ruling in 1923. The instrument has been conserved by seven conservators and was featured in the museum's "Forensic Science on Trial" exhibition [21]Verified Smithsonian Magazine — Why the Creator of the First 'Lie Detector' Regretted His Invention
Confirms Larson's polygraph is at the Smithsonian, donated by Berkeley PD in 1976, Frye ruling in 1923. The polygraph is also included in the Encyclopaedia Britannica Almanac 2003's list of 325 greatest inventions [9]Verified John Augustus Larson — Wikipedia (Additional Details)
Confirms Larson's 'Sphyggy' nickname, Smithsonian preservation, Britannica Almanac listing, and 'Frankenstein's monster' quote.
How did Max Wertheimer contribute to the development of polygraph techniques?
In 1904, Max Wertheimer and Julius Klein published a paper entitled "Psychologische Tatbestandsdiagnostik" proposing the use of word association tests to assess whether criminal suspects had committed a particular crime [11]Verified Experimental Interrogations: Tatbestandsdiagnostik — Springer Nature
Confirms Wertheimer and Klein's 1904 paper proposing word association tests for criminal investigation[12]Verified Max Wertheimer and Julius Klein — Tatbestandsdiagnostik (1904)
Confirms Wertheimer's 1904 PhD at Würzburg, publication of Psychologische Tatbestandsdiagnostik. Wertheimer's doctoral dissertation at the University of Würzburg focused on developing a lie detector for the objective study of testimony [13]Verified Max Wertheimer — Britannica Biography
Confirms Wertheimer's 1904 PhD at Würzburg involved developing a lie detector and word association method. This work established key theoretical principles about how specific psychological stimuli produce measurable reactions — insights that directly informed the logic behind the Relevant-Irrelevant Test and subsequent polygraph questioning techniques.
What is the difference between the RIT and the Control Question Technique?
The RIT uses only two question types — relevant (about the crime) and irrelevant (neutral baseline questions). The CQT, developed by John Reid in 1947, adds a third type: comparison (control) questions designed to be emotionally arousing for truthful subjects [28]Verified Reid Method: Developing Probable Lie Comparison Questions — OJP
Confirms probable lie comparison question developed by John Reid in 1947, considered one of most significant polygraph developments[29]Verified Reid's Original 1947 Paper — Journal of Criminal Law and Criminology
Confirms Reid published 'A Revised Questioning Technique in Lie-Detection Tests' in 1947 JCLC, introducing comparative response and guilt complex questions. In the CQT, a truthful subject's strongest responses shift to the comparison questions, while a deceptive subject responds most strongly to relevant questions. This three-way comparison provides a much more reliable physiological baseline than the RIT's simple relevant-versus-irrelevant contrast.
Is the Relevant-Irrelevant Test still used today?
While the RIT has been largely superseded by comparison question techniques for diagnostic testing, elements of the format have persisted in certain screening contexts [26]Verified The Polygraph and Lie Detection — National Academy of Sciences (2003)
Confirms APA-cited accuracy rates of 80–98% from studies since 1980, and comprehensive review of polygraph science. Modern polygraph practice overwhelmingly uses validated comparison question techniques — such as the CQT, Zone Comparison Technique, and their variants — as recommended by professional organisations like the American Polygraph Association.
Sources & References
Confirms Vollmer was first Berkeley police chief, described as 'father of modern policing,' served 1909–1932
Confirms Vollmer's progressive reforms, polygraph invented by Larson at his request, first used 1921
Confirms Vollmer promoted fingerprinting, polygraph machines, crime laboratories, and college-educated officers
Confirms Marston's 1915 systolic blood pressure test, Benussi's 1914 respiration research, and full polygraph development timeline
Confirms Larson created first polygraph in 1921, Keeler added GSR in 1938, Reid developed CQT replacing RIT
Confirms Larson's birth (1892), Shelburne Nova Scotia origin, Berkeley PD work, Smithsonian preservation, Britannica listing, 1965 death
Confirms R/I procedure was standard until about 1950, Larson's dormitory case, early successes and later disillusionment
Confirms Larson utilised the relevant/irrelevant test format and developed yes/no questioning procedure
Confirms Larson's 'Sphyggy' nickname, Smithsonian preservation, Britannica Almanac listing, and 'Frankenstein's monster' quote
Confirms Mosso's 1878 plethysmograph research, Lombroso's 1895 hydrosphygmograph experiments, and Keeler's 1925 ink pen innovations
Confirms Wertheimer and Klein's 1904 paper proposing word association tests for criminal investigation
Confirms Wertheimer's 1904 PhD at Würzburg, publication of Psychologische Tatbestandsdiagnostik
Confirms Wertheimer's 1904 PhD at Würzburg involved developing a lie detector and word association method
Comprehensive review confirming Keeler added GSR in 1938 based on Reverend Walter G. Summers' work, and full historical overview
Confirms Keeler's dates (1903–1949), GSR addition 1938, founding of Keeler Polygraph Institute, 1935 Portage case, and Vollmer connection
Found that electrodermally labile subjects were more frequently detected, demonstrating individual differences affect detection accuracy
Confirms individual differences in physiological reactivity affect CIT accuracy, supporting rationale for multi-channel recording
Confirms 1983 OTA report findings, NAS 2003 report conclusions, and that RIT produces heightened reactions in innocent subjects
Confirms truthful subjects may exhibit arousal to relevant questions due to importance recognition, and Reid developed CQT in the 1940s
Confirms Larson's 1932 book as referenced by the Smithsonian alongside the original instrument
Confirms Larson's polygraph is at the Smithsonian, donated by Berkeley PD in 1976, Frye ruling in 1923
Confirms Feb 2, 1935 Portage Wisconsin case, conviction of two men for assault using polygraph evidence
Confirms SCDL established in 1929, both Keeler and Reid set up polygraph training clinics in Chicago
Confirms Grignano and Loniello trial details, Feb 2 1935 date, and circumstances of Portage case
Confirms approximately 4,000 suspects tested at Berkeley PD starting 1921, LAPD tested 500+ by 1924, training programmes in Illinois
Confirms APA-cited accuracy rates of 80–98% from studies since 1980, and comprehensive review of polygraph science
Confirms polygraph proponents argue CQT has 90% or better accuracy, reviews literature since 2003 NAS report
Confirms probable lie comparison question developed by John Reid in 1947, considered one of most significant polygraph developments
Confirms Reid published 'A Revised Questioning Technique in Lie-Detection Tests' in 1947 JCLC, introducing comparative response and guilt complex questions
Confirms Reid developed CQT in 1947, Backster developed ZCT with numerical scoring, and full modern era timeline
Confirms Backster developed numerical scoring and ZCT circa 1960, widely adopted including at NCCA
Confirms Backster published Zone Comparison Technique in 1960, adopted by USAMPS in 1961
Confirms Backster introduced ZCT with three zones circa 1961, and numerical scoring systems for chart analysis in 1959
Confirms Lykken's 1959 publication introducing the Guilty Knowledge Test as a psychophysiological method
Comprehensive overview confirming CIT's false positive rate remains extremely low (~5%) across studies
Documents Japan's routine operational use of the CIT in criminal investigations involving murder, arson, and theft
Found large mean effect size of 1.59 for P300-based CIT across 54 experimental studies
Found central crime details produced stronger physiological responses than peripheral details in CIT
Comprehensive edited volume covering theoretical foundations, laboratory research, field applications, countermeasures, and legal issues
A free course on the R-I format — its origins, where it still applies, and its place in modern screening.
Start the Free Course →The earliest formats gave way to today's methods — to experience them, find a lie detector test near you and view pricing at professional locations near you.