Polygraph
A polygraph, often incorrectly referred to as a lie detector test,[1][2][3] is a junk science[4][5][6] device or procedure that measures and records several physiological indicators such as blood pressure, pulse, respiration, and skin conductivity while a person is asked and answers a series of questions.[7] The belief underpinning the use of the polygraph is that deceptive answers will produce physiological responses that can be differentiated from those associated with non-deceptive answers; however, there are no specific physiological reactions associated with lying, making it difficult to identify factors that separate those who are lying from those who are telling the truth.[8]
For other uses, see Polygraph (disambiguation).
In some countries, polygraphs are used as an interrogation tool with criminal suspects or candidates for sensitive public or private sector employment. US law enforcement and federal government agencies such as the FBI, DEA, CIA,[9] NSA,[10] and many police departments such as the LAPD and the Virginia State Police use polygraph examinations to interrogate suspects and screen new employees. Within the U.S. federal government, a polygraph examination is also referred to as a psychophysiological detection of deception (PDD) examination.[11] The average cost to administer the test in the United States is more than $700 and is part of a $2 billion industry.[12]
Assessments of polygraphy by scientific and government bodies generally suggest that polygraphs are highly inaccurate, may easily be defeated by countermeasures, and are an imperfect or invalid means of assessing truthfulness.[13][14][6][15] A comprehensive 2003 review by the National Academy of Sciences of existing research concluded that there was "little basis for the expectation that a polygraph test could have extremely high accuracy."[6] The American Psychological Association states that "most psychologists agree that there is little evidence that polygraph tests can accurately detect lies."[8]
Several proposed countermeasures designed to pass polygraph tests have been described. There are two major types of countermeasures: "general state" (intending to alter the physiological or psychological state of the subject during the test), and "specific point" (intending to alter the physiological or psychological state of the subject at specific periods during the examination, either to increase or decrease responses during critical examination periods).[29]
Security clearances[edit]
In 1995, Harold James Nicholson, a CIA employee later convicted of spying for Russia, had undergone his periodic five-year reinvestigation, in which he showed a strong probability of deception on questions regarding relationships with a foreign intelligence unit. This polygraph test later led to an investigation which resulted in his eventual arrest and conviction. In most cases, however, polygraphs are more of a tool to "scare straight" those who would consider espionage. Jonathan Pollard was advised by his Israeli handlers that he was to resign his job from American intelligence if he was ever told he was subject to a polygraph test. Likewise, John Anthony Walker was advised by his handlers not to engage in espionage until he had been promoted to the highest position for which a polygraph test was not required, to refuse promotion to higher positions for which polygraph tests were required, and to retire when promotion was mandated.[6]
In 1983, CIA employee Edward Lee Howard was dismissed when, during a polygraph screening, he truthfully answered a series of questions admitting to minor crimes such as petty theft and drug abuse. In retaliation for his perceived unjust punishment for minor offenses, he later sold his knowledge of CIA operations to the Soviet Union.[84]
Polygraph tests may not deter espionage. From 1945 to the present, at least six Americans have committed espionage while successfully passing polygraph tests. Notable cases of two men who created a false negative result with the polygraphs were Larry Wu-Tai Chin, who spied for China, and Aldrich Ames, who was given two polygraph examinations while with the CIA, the first in 1986 and the second in 1991, while spying for the Soviet Union/Russia. The CIA reported that he passed both examinations after experiencing initial indications of deception.[85] According to a Senate investigation, an FBI review of the first examination concluded that the indications of deception were never resolved.[86]
Ana Belen Montes, a Cuban spy, passed a counterintelligence scope polygraph test administered by DIA in 1994.[87]
Despite these errors, in August 2008, the US Defense Intelligence Agency (DIA) announced that it would subject each of its 5,700 prospective and current employees to polygraph testing at least once annually.[88] This expansion of polygraph screening at DIA occurred while DIA polygraph managers ignored documented technical problems discovered in the Lafayette computerized polygraph system.[89] The DIA uses computerized Lafayette polygraph systems for routine counterintelligence testing. The impact of the technical flaws within the Lafayette system on the analysis of recorded physiology and on the final polygraph test evaluation is currently unknown.[90]
In 2012, a McClatchy investigation found that the National Reconnaissance Office was possibly breaching ethical and legal boundaries by encouraging its polygraph examiners to extract personal and private information from US Department of Defense personnel during polygraph tests that purported to be limited in scope to counterintelligence matters.[91] Allegations of abusive polygraph practices were brought forward by former NRO polygraph examiners.[92]
Alternative tests[edit]
Most polygraph researchers have focused more on the exam's predictive value on a subject's guilt. However, there have been no empirical theories established to explain how a polygraph measures deception. A 2010 study indicated that functional magnetic resonance imaging (fMRI) may benefit in explaining the psychological correlations of polygraph exams. It could also explain which parts of the brain are active when subjects use artificial memories.[93] Most brain activity occurs in both sides of the prefrontal cortex, which is linked to response inhibition. This indicates that deception may involve inhibition of truthful responses.[94] Some researchers believe that reaction time (RT) based tests may replace polygraphs in concealed information detection. RT based tests differ from polygraphs in stimulus presentation duration and can be conducted without physiological recording as subject response time is measured via computer. However, researchers have found limitations to these tests as subjects voluntarily control their reaction time, deception can still occur within the response deadline, and the test itself lacks physiological recording.[95]
History[edit]
Earlier societies utilized elaborate methods of lie detection which mainly involved torture. For instance, in the Middle Ages, boiling water was used to detect liars, as it was believed honest men would withstand it better than liars.[96] Early devices for lie detection include an 1895 invention of Cesare Lombroso used to measure changes in blood pressure for police cases, a 1904 device by Vittorio Benussi used to measure breathing, the Mackenzie-Lewis Polygraph first developed by James Mackenzie in 1906 and an abandoned project by American William Moulton Marston which used blood pressure to examine German prisoners of war (POWs).[97] Marston's machine indicated a strong positive correlation between systolic blood pressure and lying.[16]
Marston wrote a second paper on the concept in 1915, when finishing his undergraduate studies. He entered Harvard Law School and graduated in 1918, re-publishing his earlier work in 1917.[98] Marston's main inspiration for the device was his wife, Elizabeth Holloway Marston.[96] "According to Marston’s son, it was his mother Elizabeth, Marston's wife, who suggested to him that 'When she got mad or excited, her blood pressure seemed to climb'" (Lamb, 2001). Although Elizabeth is not listed as Marston’s collaborator in his early work, Lamb, Matte (1996), and others refer directly and indirectly to Elizabeth's work on her husband's deception research. She also appears in a picture taken in his polygraph laboratory in the 1920s (reproduced in Marston, 1938).[99]
Despite his predecessors' contributions, Marston styled himself the "father of the polygraph". (Today he is often equally or more noted as the creator of the comic book character Wonder Woman and her Lasso of Truth, which can force people to tell the truth.)[100] Marston remained the device's primary advocate, lobbying for its use in the courts. In 1938 he published a book, The Lie Detector Test, wherein he documented the theory and use of the device.[101] In 1938 he appeared in advertising by the Gillette company claiming that the polygraph showed Gillette razors were better than the competition.[102][103][104]
A device recording both blood pressure and breathing was invented in 1921 by John Augustus Larson of the University of California and first applied in law enforcement work by the Berkeley Police Department under its nationally renowned police chief August Vollmer.[105] Further work on this device was done by Leonarde Keeler.[106] As Larson's protege, Keeler updated the device by making it portable and added the galvanic skin response to it in 1939. His device was then purchased by the FBI, and served as the prototype of the modern polygraph.[96][105]
Several devices similar to Keeler's polygraph version included the Berkeley Psychograph, a blood pressure-pulse-respiration recorder developed by C. D. Lee in 1936[107] and the Darrow Behavior Research Photopolygraph, which was developed and intended solely for behavior research experiments.[107][108][109]
A device which recorded muscular activity accompanying changes in blood pressure was developed in 1945 by John E. Reid, who claimed that greater accuracy could be obtained by making these recordings simultaneously with standard blood pressure-pulse-respiration recordings.[107][110]
Society and culture[edit]
Portrayals in media[edit]
Lie detection has a long history in mythology and fairy tales; the polygraph has allowed modern fiction to use a device more easily seen as scientific and plausible. Notable instances of polygraph usage include uses in crime and espionage themed television shows and some daytime television talk shows, cartoons and films. Numerous TV shows have been called Lie Detector or featured the device. The first Lie Detector TV show aired in the 1950s, created and hosted by Ralph Andrews. In the 1960s Andrews produced a series of specials hosted by Melvin Belli. In the 1970s the show was hosted by Jack Anderson. In early 1983 Columbia Pictures Television put on a syndicated series hosted by F. Lee Bailey.[111] In 1998 TV producer Mark Phillips with his Mark Phillips Philms & Telephision put Lie Detector back on the air on the FOX Network—on that program Ed Gelb with host Marcia Clark questioned Mark Fuhrman about the allegation that he "planted the bloody glove". In 2005 Phillips produced Lie Detector as a series for PAX/ION; some of the guests included Paula Jones, Reverend Paul Crouch accuser Lonny Ford, Ben Rowling, Jeff Gannon and Swift Boat Vet, Steve Garner.[112]
In the UK, shows such as The Jeremy Kyle Show used polygraph tests extensively. The show was ultimately canceled when a participant committed suicide shortly after being polygraphed. The guest was slated by Kyle on the show for failing the polygraph, but no other evidence has come forward to prove any guilt. Producers later admitted in the inquiry that they were unsure on how accurate the tests performed were.[113]
In the Fox game show The Moment of Truth, contestants are privately asked personal questions a few days before the show while hooked to a polygraph. On the show they asked the same questions in front of a studio audience and members of their family. In order to advance in the game they must give a "truthful" answer as determined by the previous polygraph exam.[114]
Daytime talk shows, such as Maury Povich and Steve Wilkos, have used polygraphs to supposedly detect deception in interview subjects on their programs that pertain to cheating, child abuse, and theft.[115]
In episode 93 of the US science show MythBusters, the hosts attempted to fool the polygraph by using pain when answering truthfully, in order to test the notion that polygraphs interpret truthful and non-truthful answers as the same. They also attempted to fool the polygraph by thinking pleasant thoughts when lying and thinking stressful thoughts when telling the truth, to try to confuse the machine. However, neither technique was successful for a number of reasons. Michael Martin correctly identified each guilty and innocent subject. Martin suggested that when conducted properly, polygraphs are correct 98% of the time, but no scientific evidence has been offered for this.[116]
The history of the polygraph is the subject of the documentary film The Lie Detector, which first aired on American Experience on January 3, 2023.[117]
Hand-held lie detector for US military[edit]
A hand-held lie detector is being deployed by the US Department of Defense according to a report in 2008 by investigative reporter Bill Dedman of NBC News. The Preliminary Credibility Assessment Screening System, or PCASS, captures less physiological information than a polygraph, and uses an algorithm, not the judgment of a polygraph examiner, to render a decision whether it believes the person is being deceptive or not. The device was first used in Afghanistan by US Army troops. The Department of Defense ordered its use be limited to non-US persons, in overseas locations only.[118]
Notable cases[edit]
Polygraphy has been faulted for failing to trap known spies such as double-agent Aldrich Ames, who passed two polygraph tests while spying for the Soviet Union.[88][119] Ames failed several tests while at the CIA that were never acted on.[120] Other spies who passed the polygraph include Karl Koecher,[121] Ana Montes,[122] and Leandro Aragoncillo.[123] CIA spy Harold James Nicholson failed his polygraph examinations, which aroused suspicions that led to his eventual arrest.[124] Polygraph examination and background checks failed to detect Nada Nadim Prouty, who was not a spy but was convicted for improperly obtaining US citizenship and using it to obtain a restricted position at the FBI.[125]
The polygraph also failed to catch Gary Ridgway, the "Green River Killer". Another suspect allegedly failed a given lie detector test, whereas Ridgway passed.[16] Ridgway passed a polygraph in 1984; he confessed almost 20 years later when confronted with DNA evidence.[126] Conversely, innocent people have been known to fail polygraph tests. In Wichita, Kansas in 1986, Bill Wegerle was suspected of murdering his wife Vicki Wegerle because he failed two polygraph tests (one administered by the police, the other conducted by an expert that Wegerle had hired), although he was neither arrested nor convicted of her death. In March 2004, evidence surfaced connecting her death to the serial killer known as BTK, and in 2005 DNA evidence from the Wegerle murder confirmed that BTK was Dennis Rader, exonerating Wegerle.[127]
Prolonged polygraph examinations are sometimes used as a tool by which confessions are extracted from a defendant, as in the case of Richard Miller, who was persuaded to confess largely by polygraph results combined with appeals from a religious leader.[128] In the Watts family murders, Christopher Watts failed a polygraph test and subsequently confessed to murdering his wife.[129] In the 2002 disappearance of seven-year-old Danielle van Dam of San Diego, police suspected neighbor David Westerfield; he became the prime suspect when he allegedly failed a polygraph test.[130]