Marston vs. Larson: Who Really Invented the Polygraph?

A Question That Has Never Been Fully Settled

Ask a dozen polygraph professionals who invented the lie detector, and you may get a dozen different answers. The dispute between William Moulton Marston and John Augustus Larson over the invention of the polygraph is not just an academic curiosity — it touches on fundamental questions about how scientific instruments are developed, who deserves credit when multiple researchers contribute to the same technology, and how personal ambition shapes the histories we tell.

The polygraph did not spring fully formed from a single mind. Like many transformative technologies, it emerged gradually from a series of incremental advances. The study of bodily responses to deception stretches back to antiquity, from ancient Chinese truth-testing rituals to Cesare Lombroso's hydrosphygmograph experiments in the 1890s [6]Verified Do Lie Detection Tools Really Catch Liars?
Foundational research relevant to the history and accuracy of lie detection methods. By the early twentieth century, several European and American researchers were independently exploring the relationship between physiological arousal and lying.

What makes the Marston-Larson dispute so compelling is that both men had genuine, documented contributions. The National Academies of Sciences noted that the polygraph literature "variously attributes the origins of the modern polygraph machine" to Benussi, Larson, and Keeler, while also tracing the foundational concept of using psychophysiological recordings to detect deception back to Marston's work at Harvard from 1915 to 1921 [7]Verified The Polygraph and Lie Detection — Appendix E: Historical Notes on the Modern Polygraph
Confirms the origin of Marston's work at Harvard from 1915-1921; Elizabeth Holloway's contribution; the National Research Council connection; Frye case details. The question of who "invented" the polygraph depends almost entirely on how one defines the term — and it is in that definitional ambiguity that the dispute has persisted for over a century.

Why Invention Disputes Matter in Science

History is filled with contested inventions. Edison and Tesla fought over electrical systems. Bell and Gray submitted telephone patents on the same day. Newton and Leibniz argued bitterly over calculus. In each case, the dispute reveals something important about how science progresses: rarely through a single eureka moment, and almost always through a chain of contributions that are difficult to disentangle.

The Marston-Keeler-Larson triangle is particularly instructive because it illustrates how credit for inventions is often determined not by scientific merit alone, but by institutional support, personality, self-promotion, and the needs of the broader culture. Marston was a showman who craved public attention. Larson was a meticulous scientist who shunned the spotlight. Their contrasting personalities shaped the way their respective contributions were perceived — and the way the polygraph itself was understood by the public.

Understanding this dispute matters for anyone who cares about the credibility and future of polygraph science. The profession's ability to assess its own history honestly is a measure of its maturity. And the lessons of the Marston-Larson rivalry remain relevant as new lie detection technologies — from fMRI [8]Verified What deception tasks used in the lab really do: systematic review and meta-analysis of ecological validity of fMRI deception tasks
Confirms that fMRI deception studies with high ecological validity recruit fewer brain regions, relevant to emerging lie detection technologies to EyeDetect [9]Verified You really don't recognise him? The eye-tracker as a forensic tool for concealed knowledge detection
Confirms eye-tracking combined with deep learning represents a potential advancement in contactless deception detection for forensic use — emerge with their own competing claims and controversies.

The Harvard Experiments (1913–1917)

William Moulton Marston was, by all accounts, a brilliant and eccentric figure. Born on May 9, 1893, in the Cliftondale section of Saugus, Massachusetts [1]Verified William Moulton Marston
Confirms Marston was born May 9, 1893 in Cliftondale, Saugus, Massachusetts; entered Harvard in 1911; earned BA 1915, LLB 1918, PhD 1921; created Wonder Woman; created systolic blood pressure test, he entered Harvard University in 1911 and quickly distinguished himself as a student of psychology [1]Verified William Moulton Marston
Confirms Marston was born May 9, 1893 in Cliftondale, Saugus, Massachusetts; entered Harvard in 1911; earned BA 1915, LLB 1918, PhD 1921; created Wonder Woman; created systolic blood pressure test. Under the mentorship of Hugo Münsterberg, a pioneering applied psychologist who had performed experiments on a murder suspect as early as 1907 [1]Verified William Moulton Marston
Confirms Marston was born May 9, 1893 in Cliftondale, Saugus, Massachusetts; entered Harvard in 1911; earned BA 1915, LLB 1918, PhD 1921; created Wonder Woman; created systolic blood pressure test, Marston began conducting experiments on the relationship between systolic blood pressure and deception around 1913 to 1915 [7]Verified The Polygraph and Lie Detection — Appendix E: Historical Notes on the Modern Polygraph
Confirms the origin of Marston's work at Harvard from 1915-1921; Elizabeth Holloway's contribution; the National Research Council connection; Frye case details.

According to the National Academies, it was Marston's wife, Elizabeth Holloway Marston, who first suggested the connection between emotion and blood pressure, observing that her blood pressure seemed to climb when she was angry or excited [7]Verified The Polygraph and Lie Detection — Appendix E: Historical Notes on the Modern Polygraph
Confirms the origin of Marston's work at Harvard from 1915-1921; Elizabeth Holloway's contribution; the National Research Council connection; Frye case details. This offhand observation inspired Marston's systematic investigation. Elizabeth is not always listed as his formal collaborator, but multiple scholars refer to her direct contributions to the research [1]Verified William Moulton Marston
Confirms Marston was born May 9, 1893 in Cliftondale, Saugus, Massachusetts; entered Harvard in 1911; earned BA 1915, LLB 1918, PhD 1921; created Wonder Woman; created systolic blood pressure test [7]Verified The Polygraph and Lie Detection — Appendix E: Historical Notes on the Modern Polygraph
Confirms the origin of Marston's work at Harvard from 1915-1921; Elizabeth Holloway's contribution; the National Research Council connection; Frye case details.

Marston's core method was straightforward: he used a standard sphygmomanometer — the same blood pressure cuff physicians use — to take intermittent readings of a subject's systolic blood pressure while asking them questions [10]Verified EBSCO Research Starters: Larson Constructs the First Modern Polygraph
Confirms Marston's sphygmomanometer technique was discontinuous; Larson assembled the first continuous-recording polygraph; Larson's scientific skepticism about accuracy. He would inflate the cuff, take a reading, deflate it, ask a question, then re-inflate and take another reading. The method was discontinuous — each measurement was a snapshot, not a flowing record of physiological change. In tests on fellow students, Marston reported a remarkable 96 percent success rate in detecting deception [11]Verified A Brief History of the Lie Detector
Confirms Marston reported 96% success rate in detecting deception in tests on fellow students.

Marston earned his B.A. from Harvard in 1915, his law degree (LL.B.) in 1918, and his Ph.D. in psychology in 1921 [1]Verified William Moulton Marston
Confirms Marston was born May 9, 1893 in Cliftondale, Saugus, Massachusetts; entered Harvard in 1911; earned BA 1915, LLB 1918, PhD 1921; created Wonder Woman; created systolic blood pressure test. His doctoral dissertation was titled "Systolic blood pressure symptoms of deception and constituent mental states" [1]Verified William Moulton Marston
Confirms Marston was born May 9, 1893 in Cliftondale, Saugus, Massachusetts; entered Harvard in 1911; earned BA 1915, LLB 1918, PhD 1921; created Wonder Woman; created systolic blood pressure test.

The Discontinuous Blood Pressure Test

The key feature of Marston's approach — and the primary distinction from what Larson later developed — was its intermittent nature. Marston did not record blood pressure continuously. He did not use a moving chart or kymograph. He did not measure multiple physiological channels simultaneously. His test was a series of discrete blood pressure readings taken before and after questions, with the examiner manually noting the values and looking for patterns of elevation associated with deceptive responses [10]Verified EBSCO Research Starters: Larson Constructs the First Modern Polygraph
Confirms Marston's sphygmomanometer technique was discontinuous; Larson assembled the first continuous-recording polygraph; Larson's scientific skepticism about accuracy.

This is a critical technical distinction. A series of blood pressure readings is not a "polygraph" in the technical sense of the word. The term "polygraph" means "many writings" and refers to an instrument that records multiple physiological channels simultaneously on a moving chart. Marston's test recorded one channel, intermittently. It was, more accurately, a deception detection technique rather than a polygraph instrument.

Marston was well aware of this distinction, and he generally referred to his method as the "systolic blood pressure deception test" rather than as a polygraph [10]Verified EBSCO Research Starters: Larson Constructs the First Modern Polygraph
Confirms Marston's sphygmomanometer technique was discontinuous; Larson assembled the first continuous-recording polygraph; Larson's scientific skepticism about accuracy. However, in later years, as the lie detector became a subject of intense public fascination, Marston increasingly claimed credit as the inventor of the lie detector — a claim that blurred the line between his specific blood pressure technique and the multi-channel continuous-recording instrument that others had developed. Wikipedia notes that Marston was "the creator of the systolic blood pressure test, which became one component of the modern polygraph invented by John Augustus Larson" [1]Verified William Moulton Marston
Confirms Marston was born May 9, 1893 in Cliftondale, Saugus, Massachusetts; entered Harvard in 1911; earned BA 1915, LLB 1918, PhD 1921; created Wonder Woman; created systolic blood pressure test.

Marston's Personality and Self-Promotion

Part of what makes the Marston side of this dispute so complicated is Marston himself. He was a born self-promoter who courted media attention throughout his career. After Harvard, he worked briefly in government roles — after the United States entered World War I, Marston attempted to interest the National Research Council in his work and its potential to detect espionage [7]Verified The Polygraph and Lie Detection — Appendix E: Historical Notes on the Modern Polygraph
Confirms the origin of Marston's work at Harvard from 1915-1921; Elizabeth Holloway's contribution; the National Research Council connection; Frye case details. He was assigned to the U.S. Army Sanitary Corps and sent to Camp Greenleaf, Georgia, where he attempted to apply his deception test to military personnel [12]Verified Proving Frye as a Matter of Law, Science, and History
Confirms Marston was assigned to Camp Greenleaf, Georgia during WWI to apply his deception test.

Marston's later career took increasingly unconventional turns. He became a consulting psychologist, a popular writer, and eventually the creator of the Wonder Woman comic book character, whose signature weapon — the Lasso of Truth — was directly inspired by the lie detector concept [1]Verified William Moulton Marston
Confirms Marston was born May 9, 1893 in Cliftondale, Saugus, Massachusetts; entered Harvard in 1911; earned BA 1915, LLB 1918, PhD 1921; created Wonder Woman; created systolic blood pressure test. He lived openly in a polyamorous household with his wife Elizabeth Holloway Marston and their partner Olive Byrne [1]Verified William Moulton Marston
Confirms Marston was born May 9, 1893 in Cliftondale, Saugus, Massachusetts; entered Harvard in 1911; earned BA 1915, LLB 1918, PhD 1921; created Wonder Woman; created systolic blood pressure test, a lifestyle that was scandalous by the standards of his era. Byrne was a niece of Margaret Sanger, a pioneer in the birth control movement [1]Verified William Moulton Marston
Confirms Marston was born May 9, 1893 in Cliftondale, Saugus, Massachusetts; entered Harvard in 1911; earned BA 1915, LLB 1918, PhD 1921; created Wonder Woman; created systolic blood pressure test.

Throughout all of this, Marston never stopped claiming credit for the lie detector. He appeared in Gillette razor blade advertisements in 1938, positioning himself as the "eminent psychologist and originator of the famous Lie Detector test" [7]Verified The Polygraph and Lie Detection — Appendix E: Historical Notes on the Modern Polygraph
Confirms the origin of Marston's work at Harvard from 1915-1921; Elizabeth Holloway's contribution; the National Research Council connection; Frye case details. His self-promotion also invited scrutiny — many in the scientific community regarded his claims as exceeding his actual contributions [7]Verified The Polygraph and Lie Detection — Appendix E: Historical Notes on the Modern Polygraph
Confirms the origin of Marston's work at Harvard from 1915-1921; Elizabeth Holloway's contribution; the National Research Council connection; Frye case details. The National Research Council subcommittee chair, John F. Shepard, expressed skepticism about Marston's blood pressure tests in his written reports [7]Verified The Polygraph and Lie Detection — Appendix E: Historical Notes on the Modern Polygraph
Confirms the origin of Marston's work at Harvard from 1915-1921; Elizabeth Holloway's contribution; the National Research Council connection; Frye case details.

The Berkeley Breakthrough (1921)

John Augustus Larson was a strikingly different personality from Marston. Born on December 11, 1892, in Shelburne, Nova Scotia, Canada, to Swedish parents [2]Verified John Augustus Larson (1892–1965)
Confirms Larson became likely the first American policeman with a doctoral degree and created the foundational polygraph technology in Berkeley in 1920-1921 [13]Verified John Augustus Larson — Wikipedia
Confirms Larson was born December 11, 1892 in Shelburne, Nova Scotia; earned master's in 1915 at Boston University; PhD at Berkeley 1920; instrument nicknamed 'Sphyggy'; first polygraph at Smithsonian, Larson's family moved to New England during his early childhood. He studied biology at Boston University, holding odd jobs to support himself — from busboy to stonecutter to elevator operator [13]Verified John Augustus Larson — Wikipedia
Confirms Larson was born December 11, 1892 in Shelburne, Nova Scotia; earned master's in 1915 at Boston University; PhD at Berkeley 1920; instrument nicknamed 'Sphyggy'; first polygraph at Smithsonian. In 1915, he earned a master's degree with a thesis on fingerprint identification, which inspired his interest in forensic science [13]Verified John Augustus Larson — Wikipedia
Confirms Larson was born December 11, 1892 in Shelburne, Nova Scotia; earned master's in 1915 at Boston University; PhD at Berkeley 1920; instrument nicknamed 'Sphyggy'; first polygraph at Smithsonian.

This work led him to the University of California, Berkeley, where he earned a Ph.D. in physiology in 1920, becoming the first American police officer to hold a doctoral degree [2]Verified John Augustus Larson (1892–1965)
Confirms Larson became likely the first American policeman with a doctoral degree and created the foundational polygraph technology in Berkeley in 1920-1921 [4]Verified John Augustus Larson (1892–1965)
Confirms Larson became the first American policeman with a doctoral degree and launched a new era of scientific criminal investigation. Having done moonlighting work as a student for the Berkeley Police Department, Larson joined the force in 1920 [13]Verified John Augustus Larson — Wikipedia
Confirms Larson was born December 11, 1892 in Shelburne, Nova Scotia; earned master's in 1915 at Boston University; PhD at Berkeley 1920; instrument nicknamed 'Sphyggy'; first polygraph at Smithsonian.

At Berkeley, Larson came under the influence of August Vollmer, the legendary chief of the Berkeley Police Department. Encouraged by Vollmer, Larson constructed a device in 1921 that represented a genuine leap forward in deception detection [2]Verified John Augustus Larson (1892–1965)
Confirms Larson became likely the first American policeman with a doctoral degree and created the foundational polygraph technology in Berkeley in 1920-1921 [10]Verified EBSCO Research Starters: Larson Constructs the First Modern Polygraph
Confirms Marston's sphygmomanometer technique was discontinuous; Larson assembled the first continuous-recording polygraph; Larson's scientific skepticism about accuracy. His great insight was to integrate Marston's blood pressure test with measurements for pulse and respiration to create a comprehensive lie detection tool [13]Verified John Augustus Larson — Wikipedia
Confirms Larson was born December 11, 1892 in Shelburne, Nova Scotia; earned master's in 1915 at Boston University; PhD at Berkeley 1920; instrument nicknamed 'Sphyggy'; first polygraph at Smithsonian. The instrument used a kymograph — a rotating drum covered with paper — to create a continuous written record of a subject's physiological responses simultaneously during questioning [10]Verified EBSCO Research Starters: Larson Constructs the First Modern Polygraph
Confirms Marston's sphygmomanometer technique was discontinuous; Larson assembled the first continuous-recording polygraph; Larson's scientific skepticism about accuracy.

What Made Larson's Device a True Polygraph

The critical innovations in Larson's 1921 instrument were twofold. First, the recording was continuous — rather than taking intermittent snapshots as Marston had done, Larson's device produced a flowing chart that showed moment-by-moment changes in physiology throughout the entire questioning period [10]Verified EBSCO Research Starters: Larson Constructs the First Modern Polygraph
Confirms Marston's sphygmomanometer technique was discontinuous; Larson assembled the first continuous-recording polygraph; Larson's scientific skepticism about accuracy [13]Verified John Augustus Larson — Wikipedia
Confirms Larson was born December 11, 1892 in Shelburne, Nova Scotia; earned master's in 1915 at Boston University; PhD at Berkeley 1920; instrument nicknamed 'Sphyggy'; first polygraph at Smithsonian. This meant the examiner could see exactly when physiological changes occurred relative to specific questions — a capability that was essential for drawing meaningful conclusions about deception.

Second, the device recorded multiple physiological channels simultaneously — the "poly" in "polygraph." According to the Smithsonian Institution, which now houses Larson's original instrument, it was "the first that was capable of simultaneously recording blood pressure changes, pulse rate and respiration" [14]Verified Larson Polygraph — National Museum of American History, Smithsonian Institution
Confirms Larson's original instrument is at the Smithsonian and was the first capable of simultaneously recording blood pressure, pulse rate, and respiration. This multi-channel approach provided a more comprehensive picture of the subject's physiological state, forming the foundation of how modern polygraphs work.

These two features — continuous recording and multiple simultaneous channels — are what define a polygraph instrument. By this technical definition, Larson's 1921 device was the first true polygraph. It was the first instrument that could fairly be described as recording "many writings" on a continuous chart during a structured interrogation. The polygraph was included in the Encyclopaedia Britannica Almanac 2003's list of 325 greatest inventions [13]Verified John Augustus Larson — Wikipedia
Confirms Larson was born December 11, 1892 in Shelburne, Nova Scotia; earned master's in 1915 at Boston University; PhD at Berkeley 1920; instrument nicknamed 'Sphyggy'; first polygraph at Smithsonian.

Larson's Fieldwork and Publications

Larson did not merely build the instrument in a laboratory. With Vollmer's enthusiastic support, he put it to immediate practical use. The device was implemented within the Berkeley Police Department starting in 1921 under Chief Vollmer, applying it to suspect interrogations in cases involving murder, robbery, theft, and sex crimes [13]Verified John Augustus Larson — Wikipedia
Confirms Larson was born December 11, 1892 in Shelburne, Nova Scotia; earned master's in 1915 at Boston University; PhD at Berkeley 1920; instrument nicknamed 'Sphyggy'; first polygraph at Smithsonian. Over the following fifteen years, Larson collected hundreds of files on successful criminal cases where his polygraph aided investigations [13]Verified John Augustus Larson — Wikipedia
Confirms Larson was born December 11, 1892 in Shelburne, Nova Scotia; earned master's in 1915 at Boston University; PhD at Berkeley 1920; instrument nicknamed 'Sphyggy'; first polygraph at Smithsonian. The instrument was nicknamed "Sphyggy" by the press, because reporters could not pronounce "sphygmomanometer" [13]Verified John Augustus Larson — Wikipedia
Confirms Larson was born December 11, 1892 in Shelburne, Nova Scotia; earned master's in 1915 at Boston University; PhD at Berkeley 1920; instrument nicknamed 'Sphyggy'; first polygraph at Smithsonian.

Larson also published his findings in academic journals, including a landmark 1921 paper titled "Modification of the Marston Deception Test" in the Journal of the American Institute of Criminal Law and Criminology [15]Verified Modification of the Marston Deception Test
Confirms Larson published his polygraph findings in the Journal of the American Institute of Criminal Law and Criminology in 1921. His 1932 book, Lying and Its Detection: A Study of Deception and Deception Tests, represented his most comprehensive theoretical contribution. A book review by Harold Lasswell in the journal Ethics noted Larson's balanced perspective — unlike other promoters of lie detection, Larson was critical of the polygraph and cautioned against its use in court proceedings, while documenting its utility in criminal investigations [16]Verified Book Review: Lying and its Detection; A Study of Deception and Deception Tests. John A. Larson
Confirms Larson's balanced perspective — critical of polygraph use in court while documenting utility in criminal investigations.

Despite his groundbreaking contributions, Larson was a deeply conflicted figure. He came to believe the polygraph was being misused by poorly trained examiners. He famously called the polygraph "a Frankenstein's monster" that he had spent decades combating [17]Verified Frankenstein Monster Facts
Confirms Larson called the polygraph 'a Frankenstein's monster, which I have spent over 40 years in combating'. In a 1938 study, Larson examined sixty-two suspects whose records were independently evaluated by nine psychologists — with wildly varying results, demonstrating the challenges of interpretation [10]Verified EBSCO Research Starters: Larson Constructs the First Modern Polygraph
Confirms Marston's sphygmomanometer technique was discontinuous; Larson assembled the first continuous-recording polygraph; Larson's scientific skepticism about accuracy. This intellectual honesty, while admirable, contributed to his relative obscurity compared to both Marston and Keeler.

Larson also married Margaret Taylor — notably, the first person he ever interrogated on the lie detector during the College Hall dormitory theft case [13]Verified John Augustus Larson — Wikipedia
Confirms Larson was born December 11, 1892 in Shelburne, Nova Scotia; earned master's in 1915 at Boston University; PhD at Berkeley 1920; instrument nicknamed 'Sphyggy'; first polygraph at Smithsonian. He later went to medical school at Rush Medical College and received an M.D., eventually becoming a forensic psychiatrist [13]Verified John Augustus Larson — Wikipedia
Confirms Larson was born December 11, 1892 in Shelburne, Nova Scotia; earned master's in 1915 at Boston University; PhD at Berkeley 1920; instrument nicknamed 'Sphyggy'; first polygraph at Smithsonian.

The Institutional Framework That Made Larson's Work Possible

No account of the polygraph's invention can ignore the role of August Vollmer. Born on March 7, 1876, in New Orleans to German immigrant parents [18]Verified August Vollmer — Wikipedia
Confirms Vollmer was born March 7, 1876; first police chief of Berkeley; described as 'the father of modern policing'; first to require college-educated officers; established crime lab, Vollmer became Berkeley's first police chief in 1909 after a remarkable series of events — including heroically leaping onto a runaway railroad freight car on Shattuck Avenue in 1904 to prevent a disastrous collision [18]Verified August Vollmer — Wikipedia
Confirms Vollmer was born March 7, 1876; first police chief of Berkeley; described as 'the father of modern policing'; first to require college-educated officers; established crime lab. He has been described as "the father of modern policing" [18]Verified August Vollmer — Wikipedia
Confirms Vollmer was born March 7, 1876; first police chief of Berkeley; described as 'the father of modern policing'; first to require college-educated officers; established crime lab.

Vollmer transformed American policing during his tenure from 1909 to 1932. He was the first chief to require college-educated officers and persuaded the University of California to teach criminal justice, establishing a criminal justice program in 1916 [18]Verified August Vollmer — Wikipedia
Confirms Vollmer was born March 7, 1876; first police chief of Berkeley; described as 'the father of modern policing'; first to require college-educated officers; established crime lab. He was also the first police chief to create a motorized force, to use patrol cars and radio communications, and he established one of the first crime laboratories in the United States [18]Verified August Vollmer — Wikipedia
Confirms Vollmer was born March 7, 1876; first police chief of Berkeley; described as 'the father of modern policing'; first to require college-educated officers; established crime lab. He was the first chief to use the lie detector in investigations in 1921 [19]Verified Remembering August Vollmer — Berkeleyside
Confirms Vollmer was first chief to use lie detector in investigations in 1921.

Vollmer actively recruited university-trained scientists to work in his department. Larson was one of his most important recruits. Vollmer provided Larson with the institutional support, access to subjects, and law enforcement authority that made the polygraph's development possible. Without Vollmer's patronage, Larson might never have had the opportunity to build and test his instrument in a real-world law enforcement setting.

The Berkeley Context: Scientific Policing and the Prohibition Era

The Berkeley context was important because it connected the polygraph to a broader movement toward scientific policing. Vollmer's department was a laboratory for innovation, and the polygraph was just one of many technologies he championed [18]Verified August Vollmer — Wikipedia
Confirms Vollmer was born March 7, 1876; first police chief of Berkeley; described as 'the father of modern policing'; first to require college-educated officers; established crime lab. This institutional embedding gave the polygraph a credibility that Marston's freelance demonstrations could not match.

The development of the polygraph at Berkeley did not happen in isolation from broader social forces. The 1920s were the era of Prohibition, and American cities were grappling with unprecedented levels of organized crime. Vollmer and other progressive law enforcement leaders saw scientific tools, including the polygraph, as essential weapons in the fight against sophisticated criminal organizations — a story explored in detail in The Polygraph During Prohibition.

It was also through the Berkeley connection that a third major figure entered the story: Leonarde Keeler, Vollmer's young protégé who would go on to commercialize the polygraph and become perhaps the most famous polygraph examiner of the twentieth century.

How Keeler Complicated the Invention Question

Any discussion of who invented the polygraph must reckon with Leonarde Keeler. Born on October 30, 1903, in North Berkeley, California [5]Verified Leonarde Keeler
Confirms Keeler was born October 30, 1903; died September 20, 1949; added GSR in 1938; opened first polygraph school; patented Keeler Polygraph, Keeler was named after the polymath Leonardo da Vinci and preferred to be called "Nard" [5]Verified Leonarde Keeler
Confirms Keeler was born October 30, 1903; died September 20, 1949; added GSR in 1938; opened first polygraph school; patented Keeler Polygraph. He was a Berkeley high school student and amateur magician who first encountered Vollmer through his father, naturalist Charles Keeler, who was a close friend of the police chief [5]Verified Leonarde Keeler
Confirms Keeler was born October 30, 1903; died September 20, 1949; added GSR in 1938; opened first polygraph school; patented Keeler Polygraph [20]Verified Biography of Leonarde Keeler — Office of Justice Programs
Confirms Keeler's polygraph technique remained essentially unchanged since his death in 1949.

Keeler was captivated by Larson's cardio-pneumo psychogram and worked alongside him as a keen assistant [5]Verified Leonarde Keeler
Confirms Keeler was born October 30, 1903; died September 20, 1949; added GSR in 1938; opened first polygraph school; patented Keeler Polygraph. After graduating from high school, he enrolled at UC Berkeley in the fall of 1923, later studying psychology at Stanford University under Professor Walter Miles [5]Verified Leonarde Keeler
Confirms Keeler was born October 30, 1903; died September 20, 1949; added GSR in 1938; opened first polygraph school; patented Keeler Polygraph. In 1924, Keeler's first handmade polygraph instrument, which he called the Emotograph, was destroyed in a fire at his residence [5]Verified Leonarde Keeler
Confirms Keeler was born October 30, 1903; died September 20, 1949; added GSR in 1938; opened first polygraph school; patented Keeler Polygraph.

Keeler's most significant technical contribution was the addition of the galvanic skin response (GSR) channel in 1938, measuring changes in the electrical conductivity of the skin associated with sweating [5]Verified Leonarde Keeler
Confirms Keeler was born October 30, 1903; died September 20, 1949; added GSR in 1938; opened first polygraph school; patented Keeler Polygraph [21]Verified A review of the polygraph: history, methodology and current status
Confirms Keeler added GSR channel in 1938 based on work of Rev. Walter G. Summers; made apparatus portable; Keeler did not share Larson's dedication to academia. This was based on the earlier work of Fordham University psychologist Reverend Walter G. Summers [21]Verified A review of the polygraph: history, methodology and current status
Confirms Keeler added GSR channel in 1938 based on work of Rev. Walter G. Summers; made apparatus portable; Keeler did not share Larson's dedication to academia. The addition made the polygraph a three-channel instrument — cardiovascular activity, respiration, and GSR — a configuration that remained standard for decades [21]Verified A review of the polygraph: history, methodology and current status
Confirms Keeler added GSR channel in 1938 based on work of Rev. Walter G. Summers; made apparatus portable; Keeler did not share Larson's dedication to academia. He also made the apparatus portable and patented the Keeler Polygraph in 1931 [5]Verified Leonarde Keeler
Confirms Keeler was born October 30, 1903; died September 20, 1949; added GSR in 1938; opened first polygraph school; patented Keeler Polygraph.

On February 2, 1935, Keeler conducted the first courtroom use of his Keeler Polygraph in Portage, Wisconsin, where two criminals were convicted of assault when the results were introduced as evidence [5]Verified Leonarde Keeler
Confirms Keeler was born October 30, 1903; died September 20, 1949; added GSR in 1938; opened first polygraph school; patented Keeler Polygraph. He moved to Chicago in 1930 to work at the Scientific Crime Detection Laboratory at Northwestern University and eventually opened the first polygraph school, known as the Keeler Institute [5]Verified Leonarde Keeler
Confirms Keeler was born October 30, 1903; died September 20, 1949; added GSR in 1938; opened first polygraph school; patented Keeler Polygraph.

The Bitter Larson-Keeler Rivalry

The relationship between Larson and Keeler deteriorated badly over time. Larson came to view Keeler as someone who had taken his invention and commercialized it without proper credit. Keeler, for his part, believed that his improvements and practical application of the instrument entitled him to significant recognition [21]Verified A review of the polygraph: history, methodology and current status
Confirms Keeler added GSR channel in 1938 based on work of Rev. Walter G. Summers; made apparatus portable; Keeler did not share Larson's dedication to academia.

Keeler's commercial success and showmanship in some ways paralleled Marston's approach — both men were comfortable in the public eye and understood the value of media attention. Keeler went so far as to appear as himself in the 1948 noir film Call Northside 777 [5]Verified Leonarde Keeler
Confirms Keeler was born October 30, 1903; died September 20, 1949; added GSR in 1938; opened first polygraph school; patented Keeler Polygraph. But Keeler's contributions were more directly instrumental — he built a better machine and made it available to law enforcement agencies across the country.

Devastated by his wife Katherine Applegate's departure and her subsequent death in 1944 while serving as a WASP pilot, Keeler died on September 20, 1949, at the age of 45, after suffering a stroke brought on by stress, alcohol, and cigarettes [5]Verified Leonarde Keeler
Confirms Keeler was born October 30, 1903; died September 20, 1949; added GSR in 1938; opened first polygraph school; patented Keeler Polygraph. Whether his role constitutes "invention" or "improvement" depends on how one draws the lines. The American Polygraph Association has posthumously recognized Keeler as the "father of the modern polygraph" [22]Verified Leonarde Keeler — Grokipedia
Confirms the American Polygraph Association recognized Keeler as 'father of the modern polygraph'.

The 1923 Case That Changed Everything

The Marston-Larson dispute took on legal dimensions in 1923 with the case of Frye v. United States (293 F. 1013, D.C. Cir. 1923) [3]Verified Frye standard
Confirms the Frye standard originated from Frye v. United States, 293 F. 1013 (D.C. Cir. 1923) regarding the systolic blood pressure deception test; some states still follow it. James Alphonso Frye was accused of murder in Washington, D.C. According to the National Academies account, Frye had confessed to the crime but then recanted, claiming he admitted guilt only because he had been promised a share of the reward [7]Verified The Polygraph and Lie Detection — Appendix E: Historical Notes on the Modern Polygraph
Confirms the origin of Marston's work at Harvard from 1915-1921; Elizabeth Holloway's contribution; the National Research Council connection; Frye case details. Marston administered his systolic blood pressure deception test to Frye in a D.C. jail and found his claim of innocence to be entirely truthful [7]Verified The Polygraph and Lie Detection — Appendix E: Historical Notes on the Modern Polygraph
Confirms the origin of Marston's work at Harvard from 1915-1921; Elizabeth Holloway's contribution; the National Research Council connection; Frye case details.

Frye's defense sought to introduce the results of Marston's test as evidence. The trial court refused to admit it, and the case went to the Court of Appeals for the District of Columbia. In what the U.S. Supreme Court later described as a "short and citation-free 1923 decision" [23]Verified Daubert v. Merrell Dow Pharmaceuticals, Inc.
Confirms the 1993 Supreme Court ruling superseded Frye's 'general acceptance' test; described Frye test as originating from a 1923 decision about a systolic blood pressure deception test, Associate Justice Van Orsdel delivered the ruling that would shape scientific evidence law for the next seven decades [3]Verified Frye standard
Confirms the Frye standard originated from Frye v. United States, 293 F. 1013 (D.C. Cir. 1923) regarding the systolic blood pressure deception test; some states still follow it.

The 'General Acceptance' Standard and Its Legacy

The court held that scientific evidence could only be admitted when the underlying technique had gained "general acceptance" in the relevant scientific community [3]Verified Frye standard
Confirms the Frye standard originated from Frye v. United States, 293 F. 1013 (D.C. Cir. 1923) regarding the systolic blood pressure deception test; some states still follow it. The now-famous passage stated that while courts will go a long way in admitting expert testimony from well-recognized scientific principles, "the thing from which the deduction is made must be sufficiently established to have gained general acceptance in the particular field in which it belongs" [3]Verified Frye standard
Confirms the Frye standard originated from Frye v. United States, 293 F. 1013 (D.C. Cir. 1923) regarding the systolic blood pressure deception test; some states still follow it. Since Marston's deception test had not achieved such acceptance, the evidence was excluded [3]Verified Frye standard
Confirms the Frye standard originated from Frye v. United States, 293 F. 1013 (D.C. Cir. 1923) regarding the systolic blood pressure deception test; some states still follow it.

The "Frye standard" became the dominant framework for admitting scientific evidence in American courts, though the case was not widely cited for over 10 years following the decision [24]Verified Frye Standard — Legal Information Institute
Confirms the Frye standard has been abandoned by many states and federal courts in favor of Daubert, but remains law in some states. The standard was increasingly used beginning in the 1970s, predominantly in criminal cases [24]Verified Frye Standard — Legal Information Institute
Confirms the Frye standard has been abandoned by many states and federal courts in favor of Daubert, but remains law in some states. For a deeper exploration of polygraph admissibility, see our guide on polygraph evidence in court.

In 1993, the U.S. Supreme Court's decision in Daubert v. Merrell Dow Pharmaceuticals, Inc. (509 U.S. 579) effectively superseded the Frye standard in federal courts [23]Verified Daubert v. Merrell Dow Pharmaceuticals, Inc.
Confirms the 1993 Supreme Court ruling superseded Frye's 'general acceptance' test; described Frye test as originating from a 1923 decision about a systolic blood pressure deception test. The Court held that the Federal Rules of Evidence, not Frye, provide the standard for admitting expert scientific testimony in federal trials [23]Verified Daubert v. Merrell Dow Pharmaceuticals, Inc.
Confirms the 1993 Supreme Court ruling superseded Frye's 'general acceptance' test; described Frye test as originating from a 1923 decision about a systolic blood pressure deception test. However, some states — including California, Illinois, Minnesota, New York, Pennsylvania, and Washington — still follow the Frye standard [3]Verified Frye standard
Confirms the Frye standard originated from Frye v. United States, 293 F. 1013 (D.C. Cir. 1923) regarding the systolic blood pressure deception test; some states still follow it.

The Frye case thus occupies a remarkable position in legal history: a brief ruling about a now-obsolete blood pressure test that established one of the most influential evidentiary standards in American jurisprudence. Understanding this legal dimension is essential for appreciating the ongoing evolution of polygraph admissibility standards.

Marston's Approach vs. Larson's Approach

The technical differences between Marston's and Larson's methods are crucial for understanding the invention dispute. Marston's method consisted essentially of using an ordinary sphygmomanometer to obtain periodic, discontinuous blood pressure readings during questioning [10]Verified EBSCO Research Starters: Larson Constructs the First Modern Polygraph
Confirms Marston's sphygmomanometer technique was discontinuous; Larson assembled the first continuous-recording polygraph; Larson's scientific skepticism about accuracy. It was a single-channel technique with manual notation of values by the examiner. There was no automated written record and no continuous monitoring.

Larson's approach, by contrast, involved continuous simultaneous recording of blood pressure, pulse, and respiration on a kymograph chart [10]Verified EBSCO Research Starters: Larson Constructs the First Modern Polygraph
Confirms Marston's sphygmomanometer technique was discontinuous; Larson assembled the first continuous-recording polygraph; Larson's scientific skepticism about accuracy [14]Verified Larson Polygraph — National Museum of American History, Smithsonian Institution
Confirms Larson's original instrument is at the Smithsonian and was the first capable of simultaneously recording blood pressure, pulse rate, and respiration. It measured multiple physiological channels at once, produced an automated written record, and was used in structured police interrogations. Larson's instrument provided continuous readings of blood pressure, "rather than discontinuous readings of the sort found in Marston's device" [13]Verified John Augustus Larson — Wikipedia
Confirms Larson was born December 11, 1892 in Shelburne, Nova Scotia; earned master's in 1915 at Boston University; PhD at Berkeley 1920; instrument nicknamed 'Sphyggy'; first polygraph at Smithsonian.

This distinction is not merely technical — it represents a fundamental difference in scientific methodology. Marston's discrete measurements could miss rapid changes in physiology that occurred between readings. Larson's continuous recording captured the full physiological narrative of the interrogation, making it possible for examiners to evaluate polygraph data with far greater precision. Modern polygraph science, including validated scoring systems like those studied by Donald Krapohl, builds directly on the continuous multi-channel recording paradigm that Larson pioneered [25]Verified Electrodermal Responses: When is Bigger Really Better?
Confirms electrodermal response performance peaked at 10-20% amplitude differences, demonstrating continued refinement of polygraph physiological measurement principles.

A Clash of Personalities

The personal dynamics between Marston, Larson, and Keeler reveal much about how scientific credit is assigned. Marston was a flamboyant self-promoter who moved from academia to entertainment, eventually creating Wonder Woman for DC Comics. He was comfortable making bold claims — including near-perfect accuracy rates for his blood pressure test [11]Verified A Brief History of the Lie Detector
Confirms Marston reported 96% success rate in detecting deception in tests on fellow students — and positioned himself as the father of lie detection through popular articles, public demonstrations, and commercial endorsements [7]Verified The Polygraph and Lie Detection — Appendix E: Historical Notes on the Modern Polygraph
Confirms the origin of Marston's work at Harvard from 1915-1921; Elizabeth Holloway's contribution; the National Research Council connection; Frye case details.

Larson, by contrast, was a careful scientist who grew increasingly disillusioned with how the polygraph was being used. His book review by Harold Lasswell highlighted Larson's balanced approach — unlike other promoters, he was critical of the polygraph and cautioned against its use in court proceedings [16]Verified Book Review: Lying and its Detection; A Study of Deception and Deception Tests. John A. Larson
Confirms Larson's balanced perspective — critical of polygraph use in court while documenting utility in criminal investigations. Larson's skepticism about the instrument he helped create, while scientifically admirable, meant he was less effective at claiming credit.

Keeler occupied a middle ground — more commercially minded than Larson but more technically grounded than Marston. His desire for financial and commercial success drove him to patent his polygraph, found a school, and become the first full-time private polygraph consultant [5]Verified Leonarde Keeler
Confirms Keeler was born October 30, 1903; died September 20, 1949; added GSR in 1938; opened first polygraph school; patented Keeler Polygraph [21]Verified A review of the polygraph: history, methodology and current status
Confirms Keeler added GSR channel in 1938 based on work of Rev. Walter G. Summers; made apparatus portable; Keeler did not share Larson's dedication to academia. The Larson-Keeler feud became one of the most bitter in forensic science history, as detailed in our article on Keeler vs. Larson.

Institutional Politics and the Question of Credit

The invention dispute was also shaped by institutional factors. Marston had Harvard's prestige behind his early work, but he lacked a permanent institutional home after leaving academia in the late 1920s [7]Verified The Polygraph and Lie Detection — Appendix E: Historical Notes on the Modern Polygraph
Confirms the origin of Marston's work at Harvard from 1915-1921; Elizabeth Holloway's contribution; the National Research Council connection; Frye case details. Larson had the full backing of Vollmer's Berkeley Police Department — an institution renowned for its commitment to scientific policing [18]Verified August Vollmer — Wikipedia
Confirms Vollmer was born March 7, 1876; first police chief of Berkeley; described as 'the father of modern policing'; first to require college-educated officers; established crime lab. Keeler had Northwestern University's Scientific Crime Detection Laboratory and eventually his own institute [5]Verified Leonarde Keeler
Confirms Keeler was born October 30, 1903; died September 20, 1949; added GSR in 1938; opened first polygraph school; patented Keeler Polygraph.

These institutional affiliations profoundly affected how each man's contributions were perceived. Vollmer's endorsement gave Larson's work an authority that Marston's freelance demonstrations could not match. And Keeler's commercial infrastructure ensured that his improved polygraph reached law enforcement agencies nationwide, cementing his place in the history — whether or not his improvements constituted "invention."

The field's later development through figures like Cleve Backster and Harold Burtt continued this pattern of incremental innovation building on the foundational work of multiple predecessors.

Who Deserves the Title?

The answer to who invented the polygraph depends entirely on what one means by "invented" and "polygraph." If the question is who first demonstrated that systolic blood pressure changes could indicate deception, the answer is Marston — building on even earlier work by Lombroso, Mosso, and Münsterberg. Britannica notes that "Marston's work inspired John Augustus Larson, a police officer credited with inventing the first polygraph machine" [1]Verified William Moulton Marston
Confirms Marston was born May 9, 1893 in Cliftondale, Saugus, Massachusetts; entered Harvard in 1911; earned BA 1915, LLB 1918, PhD 1921; created Wonder Woman; created systolic blood pressure test.

If the question is who first built a continuous, multi-channel recording device for detecting deception during structured interrogations — what we would recognize as a "polygraph" — the answer is clearly Larson. His 1921 instrument at the Berkeley Police Department, now preserved at the Smithsonian Institution [14]Verified Larson Polygraph — National Museum of American History, Smithsonian Institution
Confirms Larson's original instrument is at the Smithsonian and was the first capable of simultaneously recording blood pressure, pulse rate, and respiration, was the first to simultaneously record blood pressure, pulse, and respiration on a continuous chart.

If the question is who first produced a commercially viable, portable polygraph with modern channel configuration — the answer is Keeler, who added GSR in 1938 and whose polygraph technique "remained essentially unchanged" after his death in 1949 [20]Verified Biography of Leonarde Keeler — Office of Justice Programs
Confirms Keeler's polygraph technique remained essentially unchanged since his death in 1949 [22]Verified Leonarde Keeler — Grokipedia
Confirms the American Polygraph Association recognized Keeler as 'father of the modern polygraph'.

The most historically accurate answer recognizes all three: Marston laid the conceptual groundwork and popularized the idea. Larson built the first true polygraph instrument and brought scientific rigor to its use. Keeler refined, commercialized, and standardized the technology. As one research source notes about Larson, he "became likely the first American policeman with a doctoral degree and created the foundational technology that launched a new era of scientific criminal investigation" [4]Verified John Augustus Larson (1892–1965)
Confirms Larson became the first American policeman with a doctoral degree and launched a new era of scientific criminal investigation.

From Kymograph to Computer: The Legacy Continues

The contributions of Marston, Larson, and Keeler continue to shape modern polygraph practice. The physiological channels that the polygraph measures have remained largely unchanged from Keeler's original models — cardiovascular activity, respiratory activity, and electrodermal activity (GSR) [21]Verified A review of the polygraph: history, methodology and current status
Confirms Keeler added GSR channel in 1938 based on work of Rev. Walter G. Summers; made apparatus portable; Keeler did not share Larson's dedication to academia. But the technology for capturing and analyzing that data has been transformed.

Modern polygraph examinations use computerized instruments with sophisticated scoring algorithms, a far cry from the kymograph charts that Larson hand-analyzed in 1921. Research by Krapohl (2020) has shown that electrodermal response performance peaks when amplitudes differ by 10-20%, demonstrating the continued refinement of the physiological measurement principles that Larson first brought together [25]Verified Electrodermal Responses: When is Bigger Really Better?
Confirms electrodermal response performance peaked at 10-20% amplitude differences, demonstrating continued refinement of polygraph physiological measurement principles. Studies of numerical scoring practices show that examiners can achieve 82% overall accuracy in blind chart review [26]Verified Numerical scoring of polygraph charts: What examiners really do
Confirms examiners achieved 82% overall accuracy in blind chart review, with respiratory suppression as the most frequently cited criterion.

The field is also expanding beyond traditional polygraphy. Eye-tracking combined with deep learning represents a potential advancement in contactless deception detection [9]Verified You really don't recognise him? The eye-tracker as a forensic tool for concealed knowledge detection
Confirms eye-tracking combined with deep learning represents a potential advancement in contactless deception detection for forensic use, while fMRI-based approaches continue to be explored, though tasks with high ecological validity recruit fewer brain regions than artificial tasks [8]Verified What deception tasks used in the lab really do: systematic review and meta-analysis of ecological validity of fMRI deception tasks
Confirms that fMRI deception studies with high ecological validity recruit fewer brain regions, relevant to emerging lie detection technologies. Research on detecting deception from emotional expressions has shown that indirect emotion inference can successfully distinguish liars from truth tellers [27]Verified Detecting deception from emotional faces: Is that really how you feel?
Confirms indirect emotion inference successfully distinguished liars from truth tellers for negative emotional expressions.

The Marston-Larson dispute ultimately reminds us that no single individual creates a transformative technology alone. The psychophysiology underlying polygraph testing was developed over decades by dozens of researchers. And the continuing evolution of lie detection — from Marston's blood pressure cuff to Larson's kymograph to Keeler's portable polygraph to today's computerized instruments and emerging technologies — is a testament to the enduring human desire to distinguish truth from deception.

The polygraph's journey from the World War II era through the development of question formats like the Relevant-Irrelevant technique pioneered by Keeler to modern multi-issue testing illustrates how polygraph science has continually built on the foundations laid by Marston, Larson, and Keeler. Even coverage in true crime podcasts reflects the enduring public fascination that Marston first cultivated over a century ago.