John Reid’s 1945 Polygraph Chair: The Innovation Story

The Man Behind the Modern Polygraph Chair

John E. Reid (1910–1982) was an American attorney and polygraph expert whose contributions to psychophysiological detection of deception rank among the most significant in polygraph history [1]Verified History of the Polygraph
Confirms Reid (1910-1982) developed the Reid Polygraph in 1945 with metal bellows recording muscular activity in forearms, thighs, and feet[2]Verified Polygraph
Confirms a device recording muscular activity was developed in 1945 by John E. Reid. A law graduate who had worked in the Chicago Police Department [3]Verified Reid technique
Confirms Reid was a law graduate who worked in Chicago Police Department, and Reid & Inbau's partnership at the SCDL, Reid was based at the Chicago Police Scientific Crime Detection Laboratory (SCDL), where Fred Inbau assigned him to investigate the high error rate of polygraph examinations using the Relevant/Irrelevant questioning technique [4]Verified Chicago: Where Polygraph Becomes A Science
Confirms Inbau assigned Reid to investigate high error rate in R/I polygraph examinations at the SCDL.

Reid built upon the foundational work of earlier pioneers with a distinctive engineering mindset. While his predecessors — including William Marston, John Larson, and Leonarde Keeler — focused primarily on respiratory patterns, cardiovascular measurements, and galvanic skin response, Reid recognised that the physical behaviour of the examinee represented an unaddressed gap in the examiner's data [5]Verified Polygraph Development and People Behind
Confirms Reid found that unobserved muscular activity could change blood pressure and seriously affect examiner accuracy. He found that through various forms of unobserved muscular activity, a subject's blood pressure could be changed in ways that seriously affected the accuracy of the examiner's diagnosis [6]Verified Polygraph Development: Reid Polygraph
Confirms Reid devised the Reid Polygraph for recording muscular activity along with blood pressure, pulse, respiration, and GSR.

Reid published his groundbreaking findings in a 1945 article, "Simulated Blood Pressure Responses in Lie-Detector Tests and a Method for Their Detection," in the Journal of Criminal Law and Criminology [7]Verified Simulated Blood Pressure Responses in Lie-Detector Tests and a Method for Their Detection
Confirms Reid's 1945 publication in the Journal of Criminal Law and Criminology documenting his detection methods[8]Verified Simulated Blood Pressure Responses in Lie-Detector Tests — PubMed
Confirms Reid's 1945 publication in Journal of Criminal Law and Criminology, Vol. 36, pp. 201-214. This publication documented his methods for detecting when examinees were deliberately manipulating their physiological responses — a problem that had plagued examiners since the earliest days of polygraphy. For a deeper look at those early foundations, explore our article on the history of the lie detector test.

Reid & Inbau: Defining American Interrogation

Reid's partnership with Fred E. Inbau produced the seminal textbook Criminal Interrogation and Confessions, first published in 1962 by Williams & Wilkins Company [9]Verified Criminal Interrogation and Confessions (1st Edition)
Confirms first edition published January 1, 1962 by Williams & Wilkins Company[10]Verified Criminal Interrogation and Confessions (5th Edition)
Confirms the text is the standard in the field for the Reid Technique of interviewing and interrogation. The book became known as the standard reference in the field, with some calling it the "Bible" of interrogation training [11]Verified Criminal Interrogation and Confessions — AbeBooks
Confirms the reference was first published in 1962 and is widely considered the standard in interrogation training. A process of interviewing and interrogation known as the Reid Technique was initially developed in the 1940s and 1950s and described in that first edition [12]Verified Criminal Interrogation and Confessions, Fourth Edition
Confirms the Reid Technique was initially developed in the 1940s and 1950s and described in the first edition.

The first edition drew significant attention, including scrutiny from the US Supreme Court; the Miranda v. Arizona warnings were made in large part in response to the psychological dimensions of the Reid techniques [13]Verified Reid technique — Wikipedia (Miranda response)
Confirms the 1962 first edition was criticised by the US Supreme Court and Miranda warnings were partly a response to Reid techniques. Subsequent editions expanded the work — a second edition in 1967, a third in 1986, a fourth in 2001 with contributions from Joseph P. Buckley and Brian C. Jayne, and a fifth in 2011 [14]Verified Reid technique — Wikipedia (editions)
Confirms second edition 1967, third edition 1986, Reid's death in 1982, and Buckley becoming president. Reid died on January 11, 1982, and Joseph Buckley became president of John E. Reid & Associates [15]Verified Reid technique — Wikipedia (company)
Confirms Reid died in 1982, Buckley became president, and by 2013 the company trained more interrogators than any other. By 2013, the company trained more interrogators than any other organisation in the world [15]Verified Reid technique — Wikipedia (company)
Confirms Reid died in 1982, Buckley became president, and by 2013 the company trained more interrogators than any other. For more on the evolution of interrogation methods, see our comparison of the Reid Technique vs. PEACE Model.

The Countermeasure Gap Before 1945

Before Reid's innovation, polygraph instruments measured three core physiological channels: blood pressure and pulse, respiration, and galvanic skin response (GSR) [16]Verified History of Polygraph — Keeler Polygraph
Confirms Keeler added GSR in 1939 and his device served as the prototype of the modern polygraph. The Keeler Polygraph, patented in 1939 and purchased by the FBI as the prototype of the modern polygraph [17]Verified History of Polygraph — Ohio Polygraph Services
Confirms Keeler patented the Keeler Polygraph in 1939 as the prototype of the modern polygraph, incorporated these three channels but had no means of detecting physical manipulation by the examinee.

Reid's 1945 research demonstrated that examinees could deliberately alter their blood pressure readings through subtle muscular movements — pressing their feet against the floor, tensing their arms, or contracting their thigh muscles — creating false responses that were indistinguishable from genuine physiological reactions on the standard polygraph channels [7]Verified Simulated Blood Pressure Responses in Lie-Detector Tests and a Method for Their Detection
Confirms Reid's 1945 publication in the Journal of Criminal Law and Criminology documenting his detection methods[6]Verified Polygraph Development: Reid Polygraph
Confirms Reid devised the Reid Polygraph for recording muscular activity along with blood pressure, pulse, respiration, and GSR. This vulnerability meant that an examiner relying solely on traditional measurements could be systematically deceived by a knowledgeable subject.

The patent text itself noted that existing equipment had been "principally concerned with recording blood pressure, pulse and respiration cycles" and acknowledged that "in about 20% of the cases the results obtained are not acceptable" [18]Verified U.S. Patent No. 2,538,125 — Google Patents
Confirms patent filed November 19, 1945, granted January 16, 1951, to inventor John E. Reid for polygraph apparatus recording muscular activity. Reid's insight was that muscular activity data needed to be recorded simultaneously with the standard polygraph measurements to close this gap [5]Verified Polygraph Development and People Behind
Confirms Reid found that unobserved muscular activity could change blood pressure and seriously affect examiner accuracy.

How Reid's Polygraph Chair Worked

In 1945, Reid developed the Reid Polygraph, a device that recorded muscular activity in the forearms, thighs, and feet thanks to metal bellows placed under the arms and seat of the polygraph chair [1]Verified History of the Polygraph
Confirms Reid (1910-1982) developed the Reid Polygraph in 1945 with metal bellows recording muscular activity in forearms, thighs, and feet[2]Verified Polygraph
Confirms a device recording muscular activity was developed in 1945 by John E. Reid. These metal bellows were small, accordion-like pneumatic devices that compressed when a subject applied pressure through muscular movements. The compressed bellows displaced air through tubing connected to the polygraph's recording pens, creating visible deflections on the chart paper [18]Verified U.S. Patent No. 2,538,125 — Google Patents
Confirms patent filed November 19, 1945, granted January 16, 1951, to inventor John E. Reid for polygraph apparatus recording muscular activity.

This purely mechanical system required no electrical power — it operated on the same pneumatic principles used by the respiratory bellows that had been part of polygraph instruments since John Larson's original 1921 design [19]Verified Polygraph — Wikipedia (Larson 1921)
Confirms the polygraph was invented in 1921 by John Augustus Larson at UC Berkeley. The elegance of Reid's approach was that it added a fourth physiological channel without requiring new electronic technology, making it immediately compatible with existing Keeler and Stoelting polygraph instruments.

Reid's chair monitored three distinct body zones simultaneously: forearm activity through bellows embedded in the armrests, thigh and gluteal muscle activity through bellows in the seat cushion, and foot movement including toe pressing and ankle flexion [1]Verified History of the Polygraph
Confirms Reid (1910-1982) developed the Reid Polygraph in 1945 with metal bellows recording muscular activity in forearms, thighs, and feet[2]Verified Polygraph
Confirms a device recording muscular activity was developed in 1945 by John E. Reid. These three zones correspond precisely to the most common physical countermeasure techniques used by examinees attempting to manipulate their results.

The Innovation in Context

Reid claimed that greater accuracy could be obtained by making these muscular activity recordings simultaneously with standard blood pressure and other polygraph measurements [20]Verified Polygraph — Wikipedia (Reid muscular activity)
Confirms Reid claimed greater accuracy through simultaneous recording of muscular activity with standard measurements. This was a critical conceptual advance: rather than replacing existing measurement channels, Reid added an entirely new dimension of data. The examiner could now correlate muscular activity with respiratory, cardiovascular, and electrodermal changes in real time, creating a far more complete picture of the examinee's physiological state.

Frank S. Horvath's 2019 study in European Polygraph, "Chicago: Birthplace of Modern Polygraphy," documented Reid's chair with historical photographs and confirmed that the device was similar in function to those in widespread use today, though current technology is more advanced [21]Verified Chicago: Birthplace of Modern Polygraphy
Documents Reid's chair with historical photographs and confirms Chicago's central role in polygraphy development. Horvath reproduced a figure from Reid's 1945 publication showing a rise in the cardio tracing due to induced muscular tension in the right arm, alongside a similar display showing a blood pressure rise induced by an examinee pressing his feet to the floor [21]Verified Chicago: Birthplace of Modern Polygraphy
Documents Reid's chair with historical photographs and confirms Chicago's central role in polygraphy development.

Patent Details and Scope

Reid filed his patent application on November 19, 1945, under application number US629615A [18]Verified U.S. Patent No. 2,538,125 — Google Patents
Confirms patent filed November 19, 1945, granted January 16, 1951, to inventor John E. Reid for polygraph apparatus recording muscular activity. U.S. Patent No. 2,538,125 was granted on January 16, 1951, with John E. Reid listed as the sole inventor [18]Verified U.S. Patent No. 2,538,125 — Google Patents
Confirms patent filed November 19, 1945, granted January 16, 1951, to inventor John E. Reid for polygraph apparatus recording muscular activity. The patent described "polygraph apparatus for recording bodily changes in a subject under observation, and relates particularly to apparatus for recording muscular activity of said subject to be employed in conjunction with the usual blood pressure, pulse cycle and respiration cycle measurements" [18]Verified U.S. Patent No. 2,538,125 — Google Patents
Confirms patent filed November 19, 1945, granted January 16, 1951, to inventor John E. Reid for polygraph apparatus recording muscular activity.

The patent covered the complete integrated system — the chair, the pneumatic bellows, the air tubing, and the connection to the recording apparatus. The patent drawings, spanning five sheets, detailed the mechanical arrangement of the bellows within the chair structure, the manifold and conduit system for air transmission, and the tambour mechanisms that converted air pressure changes into pen movements on the chart paper [18]Verified U.S. Patent No. 2,538,125 — Google Patents
Confirms patent filed November 19, 1945, granted January 16, 1951, to inventor John E. Reid for polygraph apparatus recording muscular activity.

Reid's Patent 2,538,125 was subsequently cited as prior art in later polygraph instrument patents, including US3915156A, a polygraph featuring a cardiograph with dicrotic notch enhancement [22]Verified US3915156A — Polygraph with dicrotic notch enhancement
Cites Reid's Patent 2,538,125 (1951) as prior art in subsequent polygraph instrument patent. This citation chain demonstrates that Reid's innovation was recognised as a foundational contribution to the ongoing development of polygraph instrumentation.

Research Validating Movement Detection

The value of Reid's movement-sensing concept has been validated by decades of peer-reviewed research. The 1988 study by Mike Stevenson and Glenn Barry, published in the journal Polygraph, tested the effectiveness of a motion chair with 12 subjects who had recently completed 10 weeks of a 12-week polygraph examiners course at the Canadian Police College [23]Verified Use of a Motion Chair in the Detection of Physical Countermeasures
Motion chair detected 85% of physical countermeasures vs. 9% by examiner and 36% by observer. The results were striking: of 33 scoreable physical countermeasures, only 9% were identified by the examiner, 36% by a dedicated observer, but 85% were detected by the motion chair [23]Verified Use of a Motion Chair in the Detection of Physical Countermeasures
Motion chair detected 85% of physical countermeasures vs. 9% by examiner and 36% by observer. The motion chair used a strain gauge — a pressure-sensitive recording device smaller than a dime — that was electronically activated and capable of linear sensitivity calibration [23]Verified Use of a Motion Chair in the Detection of Physical Countermeasures
Motion chair detected 85% of physical countermeasures vs. 9% by examiner and 36% by observer.

The 2008 study by Jack Ogilvie and Donnie W. Dutton confirmed these findings using updated technology. The study found that the addition of countermeasure sensors significantly improved examiners' performance in detecting physical countermeasures used by examinees [24]Verified Improving the Detection of Physical Countermeasures With Chair Sensors
Chair sensors significantly improved countermeasure detection without affecting scores for non-countermeasure examinees. Critically, the study also determined that the presence of sensor information did not affect the scores or countermeasure ratings of examinees who had not been programmed to perform countermeasures [24]Verified Improving the Detection of Physical Countermeasures With Chair Sensors
Chair sensors significantly improved countermeasure detection without affecting scores for non-countermeasure examinees — meaning the sensors help catch manipulation without penalising honest examinees.

Ogilvie and Dutton further noted that examiners do not perform above chance levels when relying on only the conventional polygraph channels to identify countermeasures [24]Verified Improving the Detection of Physical Countermeasures With Chair Sensors
Chair sensors significantly improved countermeasure detection without affecting scores for non-countermeasure examinees. This finding powerfully validates Reid's original 1945 insight that visual observation alone was insufficient and that objective, instrumental measurement of physical movement was essential.

Why Countermeasure Detection Matters Today

Research by Honts, Raskin, and Kircher (1994) demonstrated that both mental and physical countermeasures can reduce polygraph accuracy, with each type enabling approximately 50% of subjects to defeat the test when no countermeasure sensors are in use [25]Verified Mental and Physical Countermeasures Reduce the Accuracy of Polygraph Tests
Confirms physical and mental countermeasures each enabled approximately 50% of subjects to defeat the polygraph test. This underscores the critical importance of the movement detection channel that Reid pioneered.

The US government takes countermeasure detection so seriously that it launched criminal investigations targeting individuals who teach others how to defeat polygraph examinations [26]Verified Polygraph — Wikipedia (countermeasure indictments)
Confirms US federal government began indicting individuals teaching methods to defeat polygraph tests in 2013. Modern polygraph systems incorporate activity sensors as standard equipment precisely because of the vulnerability that Reid first identified and addressed in 1945. For more on how APA validated techniques incorporate countermeasure detection, see our dedicated guide.

The CQT Revolution

While developing his polygraph chair, Reid simultaneously worked on a revolutionary questioning methodology. In 1947, Reid developed the Control Question Technique (CQT), which incorporated comparison questions designed to be emotionally arousing for non-deceptive subjects and less emotionally arousing for deceptive subjects [27]Verified History of Polygraph — Ohio Polygraph Services (CQT)
Confirms Reid developed the CQT in 1947 and Keeler founded first polygraph school in 1948[28]Verified Reid Method: Developing Probable Lie Comparison Questions
Confirms the probable lie comparison question (Reid Examination Technique) was developed by Reid in 1947. He published his revised questioning technique in a 1947 article, "A Revised Questioning Technique in Lie-Detection Tests," in the Journal of Criminal Law and Criminology [29]Verified A Revised Questioning Technique in Lie-Detection Tests
Confirms Reid's 1947 publication of the revised questioning technique in the Journal of Criminal Law and Criminology.

As described by Synnott, Dietzel, and Ioannou in their comprehensive 2015 review, since its inception by John E. Reid in the late 1940s, the CQT remains the most widely used polygraph test [30]Verified A Review of the Polygraph: History, Methodology and Current Status
Confirms CQT inception by Reid in the late 1940s as the most widely used polygraph test. The CQT replaced the Relevant/Irrelevant Question Technique (RIT) and represented a major breakthrough in polygraph methodology [27]Verified History of Polygraph — Ohio Polygraph Services (CQT)
Confirms Reid developed the CQT in 1947 and Keeler founded first polygraph school in 1948. Reid is therefore considered the "father of controls" in polygraphy [1]Verified History of the Polygraph
Confirms Reid (1910-1982) developed the Reid Polygraph in 1945 with metal bellows recording muscular activity in forearms, thighs, and feet.

Reid's dual innovations — the movement-sensing chair and the Control Question Technique — emerged from the same period of intensive research and fundamentally reshaped the practice of polygraphy. For a detailed examination of how the CQT was developed, see our article on John Reid's 1947 Control Question. Reid's work also influenced later pioneers such as James Allan Matte, who developed the Quadri-Track Zone Comparison Technique.

Professional Standards Requiring Movement Detection

The importance of Reid's innovation is reflected in modern professional standards. ASTM Committee E52 on Forensic Psychophysiology was formed in 1996 and has jurisdiction over multiple standards governing polygraph testing [31]Verified ASTM Committee E52 on Forensic Psychophysiology
Confirms Committee E52 formed in 1996 with jurisdiction of 7 standards for polygraph testing. These standards cover all aspects of polygraphy, from research methodology to ethics and instrumentation [32]Verified Would I Lie To You? — ASTM Standardization News
Confirms ASTM E52 develops standards covering all aspects of polygraphy from research to ethics.

Key ASTM standards include E2062, the Standard Guide for PDD Examination Standards of Practice; E2386, the Standard Guide for Conduct of PDD Screening Examinations; E2439, covering instrumentation, sensors, and operating software; E2229, addressing data interpretation practices; E2063, governing calibration and functionality checks; E1954, covering research conduct; and E2035 on terminology [33]Verified ASTM Forensic Science Standards — BOS Volume 14.02
Lists multiple ASTM polygraph standards including E2062, E2386, E2229, E2063, E2439, E1954, E2031, and E2035[34]Verified ASTM E2063 — Calibration and Functionality Checks for PDD
Confirms standard provides guidelines for calibration and instrumentation used in polygraph examinations. The ASTM E52.02 subcommittee on Instrumentation focuses specifically on standards for manufacturers of polygraph instruments, including sensor requirements [32]Verified Would I Lie To You? — ASTM Standardization News
Confirms ASTM E52 develops standards covering all aspects of polygraphy from research to ethics.

The International Society of Polygraph Examiners requires that all polygraph instruments include a separate data channel specifically designed to record physical body movements [35]Verified Standards of Practice — International Society of Polygraph Examiners
Confirms requirement for instruments to include data channel for recording physical body movements. This requirement directly descends from the principle Reid established in 1945 — that movement data is essential for reliable examinations. To learn more about how professional standards evolved, see our guide on the history of APA standards.

From Pneumatic Bellows to Electronic Sensors

The transition from Reid's original pneumatic design to modern electronic sensors represents a remarkable evolution in technology while preserving the fundamental concept Reid established. Today's polygraph chairs use electronic activity sensors and strain gauges rather than pneumatic bellows. The Lafayette 76875S Activity Sensor, for example, uses multiple sensors to detect movement over the entire seat area and provides automatic zeroing of the measurement range independent of the subject's weight [36]Verified Lafayette 76875S Activity Sensor — Seat Pad
Confirms modern activity sensors detect minor and major examinee movements with multiple sensors and automatic zeroing.

Modern activity sensors are precision instruments capable of detecting very slight movement [36]Verified Lafayette 76875S Activity Sensor — Seat Pad
Confirms modern activity sensors detect minor and major examinee movements with multiple sensors and automatic zeroing. With the sensitivity of the polygraph set high, the Activity Sensor may even detect heartbeats or respiration signals on some examinees [36]Verified Lafayette 76875S Activity Sensor — Seat Pad
Confirms modern activity sensors detect minor and major examinee movements with multiple sensors and automatic zeroing. Unlike the previous weight-sensing Activity Sensors, current units provide automatic zeroing independent of weight [36]Verified Lafayette 76875S Activity Sensor — Seat Pad
Confirms modern activity sensors detect minor and major examinee movements with multiple sensors and automatic zeroing, eliminating the manual calibration that was required with Reid's original pneumatic system.

Modern polygraph chairs now come with built-in and pre-wired seat activity sensor pads [37]Verified Portable Subject's Chair with Activity Sensor
Confirms modern polygraph chairs come with built-in and pre-wired Seat Activity Sensor pads. Lafayette Instrument Company offers complete polygraph chair systems with integrated seat and foot activity sensors, representing the direct technological descendants of Reid's 1945 concept [38]Verified Polygraph Chairs — Lafayette Instrument Company
Confirms Lafayette offers polygraph chairs with integrated seat and foot activity sensors. For a comprehensive look at modern equipment, see our Lafayette Instrument Company product guide.

Chicago's Enduring Legacy in Polygraphy

Reid's innovations took place within a broader ecosystem of polygraph development centred in Chicago. Both Leonarde Keeler and John Reid set up polygraph training clinics in Chicago after working at the Scientific Crime Detection Laboratory (SCDL), which was established in 1929 in the aftermath of the St. Valentine's Day Massacre [3]Verified Reid technique
Confirms Reid was a law graduate who worked in Chicago Police Department, and Reid & Inbau's partnership at the SCDL[39]Verified Chicago: Where Polygraph Becomes A Science (SCDL)
Confirms Inbau assigned Reid to investigate high error rates and the SCDL's role in polygraph development. Fred Inbau, who became the SCDL's director after Northwestern University sold it to the Chicago police in 1938, trained police officers and prosecutors and directly oversaw Reid's early research [3]Verified Reid technique
Confirms Reid was a law graduate who worked in Chicago Police Department, and Reid & Inbau's partnership at the SCDL.

In 1948, Leonarde Keeler founded the world's first polygraph school — the Keeler Polygraph Institute — in Chicago [27]Verified History of Polygraph — Ohio Polygraph Services (CQT)
Confirms Reid developed the CQT in 1947 and Keeler founded first polygraph school in 1948. In 1960, Cleve Backster, building upon the Reid Control Question Technique, developed the Backster Zone Comparison Technique, which primarily involved an alteration of the Reid question sequencing [27]Verified History of Polygraph — Ohio Polygraph Services (CQT)
Confirms Reid developed the CQT in 1947 and Keeler founded first polygraph school in 1948. Backster also introduced a quantification system of chart analysis, making polygraph interpretation more objective and scientific [27]Verified History of Polygraph — Ohio Polygraph Services (CQT)
Confirms Reid developed the CQT in 1947 and Keeler founded first polygraph school in 1948.

This lineage demonstrates how Chicago served as the birthplace of modern polygraphy, with Reid's contributions forming a critical bridge between the pioneering instrument work of Keeler and the systematic analytical methods that followed. For more on how computerised analysis later transformed the field, see our article on Joseph Kubis, the Fordham University researcher who was the first to explore computer applications for polygraph chart analysis [27]Verified History of Polygraph — Ohio Polygraph Services (CQT)
Confirms Reid developed the CQT in 1947 and Keeler founded first polygraph school in 1948.

Publications and Professional Impact

Reid's 1945 article in the Journal of Criminal Law and Criminology was described as one of "two noteworthy contributions to the field of scientific lie detection" [29]Verified A Revised Questioning Technique in Lie-Detection Tests
Confirms Reid's 1947 publication of the revised questioning technique in the Journal of Criminal Law and Criminology. His 1947 article on the revised questioning technique followed in the same journal, establishing the theoretical framework for the CQT [29]Verified A Revised Questioning Technique in Lie-Detection Tests
Confirms Reid's 1947 publication of the revised questioning technique in the Journal of Criminal Law and Criminology. Reid co-authored the landmark book Truth and Deception: The Polygraph ("Lie Detector") Technique with Fred Inbau in 1953, followed by Criminal Interrogation and Confessions in 1962 [10]Verified Criminal Interrogation and Confessions (5th Edition)
Confirms the text is the standard in the field for the Reid Technique of interviewing and interrogation[40]Verified Inbau The First Polygraph — Barland Interview
Confirms Reid died on January 11, 1982 and Inbau died on May 25, 1998, and the interview at Reid College of Detection of Deception.

Reid's work at the SCDL placed him at the nexus of law enforcement and scientific innovation. Inbau had specifically assigned Reid to investigate the high error rate of polygraph examinations using the Relevant/Irrelevant questioning technique [39]Verified Chicago: Where Polygraph Becomes A Science (SCDL)
Confirms Inbau assigned Reid to investigate high error rates and the SCDL's role in polygraph development, and Reid's response — developing both a new instrument (the movement chair) and a new methodology (the CQT) — addressed the problem from two complementary angles.

Horvath's research confirms that Reid was "a most generous and devoted man who was professionally dedicated to his chosen field of interest" who "emphasized the sharing of knowledge through participation in associations and in publication" [21]Verified Chicago: Birthplace of Modern Polygraphy
Documents Reid's chair with historical photographs and confirms Chicago's central role in polygraphy development. Reid was one of the leading practitioners who helped merge the separate professional groups of examiners into unified organisations [21]Verified Chicago: Birthplace of Modern Polygraphy
Documents Reid's chair with historical photographs and confirms Chicago's central role in polygraphy development, contributing to the professionalisation of polygraph practice. For related history, explore the role of the DoD Polygraph Institute and how Frances Wake became the first female polygraph examiner.

The Continuing Relevance of Movement Detection

The polygraph chair remains one of the most practically important components of the modern polygraph examination. Every professional polygraph system today includes movement detection capability, and activity sensors are listed among the required components for instruments certified under APA and ASTM standards [35]Verified Standards of Practice — International Society of Polygraph Examiners
Confirms requirement for instruments to include data channel for recording physical body movements[33]Verified ASTM Forensic Science Standards — BOS Volume 14.02
Lists multiple ASTM polygraph standards including E2062, E2386, E2229, E2063, E2439, E1954, E2031, and E2035.

As research has consistently shown, human observation alone is insufficient for detecting physical countermeasures. The 1988 Stevenson and Barry study found that examiners visually detected only 9% of countermeasures, while the motion chair detected 85% [23]Verified Use of a Motion Chair in the Detection of Physical Countermeasures
Motion chair detected 85% of physical countermeasures vs. 9% by examiner and 36% by observer. The 2008 Ogilvie and Dutton study confirmed that sensor data improves detection without generating false positives [24]Verified Improving the Detection of Physical Countermeasures With Chair Sensors
Chair sensors significantly improved countermeasure detection without affecting scores for non-countermeasure examinees. These findings validate Reid's original insight that the examiner needed objective data about the subject's physical movements.

For practitioners, understanding the historical development of the polygraph chair provides important context for interpreting movement channel data. The principles Reid established — monitoring forearm, thigh, and foot activity; integrating movement data with other physiological channels; using temporal correlation to identify countermeasures — remain the foundational framework for modern countermeasure detection.

If you are preparing for a polygraph examination and want to understand the process, book your test with confidence knowing that today's equipment incorporates over 80 years of engineering refinement traced directly back to Reid's 1945 innovation. For those interested in a career in the field, learn more about how to become a polygraph examiner.