Forensics: exact science or dramatised fiction? #5
The invention of the so-called Lie Detector or Polygraph test was the result of an old and obsessive desire of mankind for centuries—to be able to peep into the minds of others and thus acquire control over them. It was also a reflection of how, in the early years of modern science, people used and abused every new find for all sorts of things. Many 19th century United States entrepreneurs advertised and sold mineral oil laced with useless herbs as a panacea for all sorts of medical problems. Cocaine and opium were used as wonder drugs. By the 1880s, electric shock belts were claimed to cure impotence and kidney pains; in 1909, a vibrator for women was claimed to cure hysteria!
Going along this popular enthusiasm associated with new scientific discoveries, in 1858 French physiologist Étienne-Jules Marey claimed that he detected bodily changes as responses to uncomfortable stressors, including nausea and sharp noises. In the 1890s, Italian criminologist Cesare Lombroso claimed he had invented a special glove to measure a criminal suspect’s blood pressure during interrogation. Incidentally, this Lombroso also believed that criminality was inherited and that criminals could be identified by physical attributes such as hawk-like noses and bloodshot eyes, etc.—his fanciful theories stand thoroughly discredited now.
In 1915, William Moulton Marston invented a systolic blood pressure cuff and claimed that he found links between vital signs and emotions. Being a ‘racist’ like Lombroso, he also believed that he could not be fully confident in the results on African-Americans because their minds were more primitive than those of whites! In 1921, John Augustus Larson, a policeman in Berkeley, claimed that he had invented a contraption called ‘cardio-pneumo-psychogram’. This is generally regarded as the first lie detector or polygraph.
How popular culture drove pseudo-science?
No scientific basis of such claims has ever been produced. The Lie Detector test remains a massive pseudo-scientific fraud—as big as it could ever be imagined. Lie detector or Polygraph tests became popular due to popular culture, fiction and films that became obsessed with them.
The modern polygraph measures physiological signals such as heart rate, sweating, and blood pressure—respiration is measured through a pneumograph; electrodermal skin response through a galvanometer; and blood volume and pulse rate through a cardiospymograph.
Based on a religious notion, not science
The unstated idea of the polygraph depends on a religious notion that man is inherently good—that the soul of even a criminal is good and it is only the mind that is perverted. Hence the soul or the inner self sides with the truth whereas the mind may be inclined towards the untruth. This tussle results in physiological responses when the subject is lying. Needless to say, the very premise is hopelessly wrong and without any scientific basis at all.
How rigorous science busts it?
In his famous book ‘Rape of the Mind’, Joost Meerloo has shown that at most the polygraph may indicate that the human guinea pig under investigation is reacting more emotionally to certain questions than to others.
Because there is no characteristic physiological response associated with lying, it is not possible to ask a person to answer a relevant question about an alleged misdeed (e.g., “Did you shoot so-and-so police officer because he was so dumb and irritating?”), record nervous system reactions, and make a determination of truthfulness. Lie-detectors, therefore, attempted to circumvent this problem by including in addition to a relevant question, a comparison or control question that is also used to elicit physiological reactions. For the above-mentioned question regarding shooting some dumb police officer, the control question could run like, “Have you ever hurt someone to get revenge?”
William G. Iacono, in his paper “Forensic ‘Lie Detection’: Procedures Without Scientific Basis”, undertook a critical overview of the scientific status of the Control Question Test (CQT). Two assumptions, without any scientific reason, are implicit in the idea of CQT. The first is that innocent individuals must be more responsive to control than relevant questions. The second is that guilty persons must respond more intensely to relevant than control questions. Iacono has shown that the QCT is based on an implausible set of assumptions that makes it biased against innocent individuals and easy for guilty persons to defeat using countermeasures.
Discredited in high profile cases also
Even as the technique has been debunked a thousand times, its most historical bust was in the case of Aldrich Hazen Ames. Ames, a 31-year veteran CIA counterintelligence officer, committed espionage against the US by spying for the Soviet Union and later Russia. He betrayed the US government from 1985 to 1994 and did them great damage. Yet, this man managed to pass two polygraph tests in 1986 and 1991 by the Office of Security even as he was actively spying then. And, he managed this even as he admitted that he was very anxious and tremendously worried when he was informed that he was scheduled for a polygraph exam in May of 1986, one year after he had begun his espionage activity for the KGB.
The report of the Senate Select Committee on Intelligence reveals that in 1986, Ames was tested on a series of issues having to do with unauthorized contacts with a foreign intelligence service, unauthorized disclosure of classified information, and financial irresponsibility. Ames gave consistently deceptive responses to issues related to whether he had been ‘pitched’ (that is, asked to work for) by a foreign intelligence service. The CIA examiner deemed Ames truthful.
For the 1991 test, the polygraph supervisor and the examiner were aware that there was some issue about Ames’s unexplained wealth. Once the polygraph test began, he was asked whether he was concealing any financial difficulties from the Agency. To this question Ames answered in the negative, showing no signs of deception. Ames gave them a story that his prosperity was the result of money given to him by his Colombian wife’s wealthy family and they accepted it!
Ames showed no reaction when he was asked whether he was working for a foreign intelligence service. The deception was supposedly indicated, however, when he was asked whether he was concealing contacts with foreign nationals. As per the standard CIA practice, he was asked to return in a few days. That time he passed the test easily.
Readers must note that if the polygraph tests conducted by the most resourceful agency in the world, namely the CIA with the most sophisticated equipment at their disposal, could be fooled, where do police forces of districts in India stand?
Ultimate Dismissal by the Hon’ble Supreme Court
The final and ultimate condemnation of the lie-detector came through the hands of a Three-Judge Bench of the Supreme Court in the case of Selvi & Ors vs State of Karnataka & Anr (2010).
The Supreme Court noted, “The premise behind these tests is questionable because the measured changes in physiological responses are not necessarily triggered by lying or deception. Instead, they could be triggered by nervousness, anxiety, fear, confusion or other emotions… Errors may also result from `memory hardening, that is, a process by which the subject has created and consolidated false memories about a particular incident…The biggest concern about polygraph tests is that an examiner may not be able to recognise deliberate attempts on part of the subject to manipulate the test results…The most commonly used `countermeasures’ are those of creating a false sense of mental anxiety and stress at the time of the interview, so that the responses triggered by lying cannot be readily distinguished.” The Supreme Court also cited the reports of the US National Research Council of the National Academies (NRC) and the British Psychological Society (BPS) in its support.
If, in spite of this, any police officer uses it even now, he must be proceeded against.