Saturday, 23 June 2012

Lie detector

 Who among us would have envisioned a machine that could figure out whether a person was lying or not? There was time when finding this secret was just in hands of mystical beings or God. Isn’t it startling how a machine can read a person’s mind?

Inventor of Lie detector called it cardio-pneumo-psychograph. It was a magic box that had the power to peep in one’s mind and figure out who was pilfering jewelry and cash at college boardinghouse. But to future generations and newspaper reading people, this magic box was lie detector, a machine to help a way out of doubtful scientific credentials and dubious ethical aura.

In the era that led to birth of scientific industrial management, I.Q. test and time motion study, a group of American Inventors and the social reformers had dreamt of a device that could separate truth from the deception by measuring body responses like pulse rate, blood pressure.
One of the early proponents claimed that this ‘mechanical instrument of future’ would replace jury deliberations, conventional police interrogations. It would also lend a hand to government and private companies in weeding out spies, thieves. It would beam in deepest corners of human psyche and advancing works of psychiatrists. But the man behind the invention, John Larson despaired while taking his breaths and called it a Frankenstein’s monster that had sucked 40 years of his life.
The persistent as well as unusual grip of the lie detector on American thoughts provided rich material for Lie Detector’s invention. Various cases including that of Torso Murderers, Cleveland, story of Dick Tracy or William James stirred with scientific visions led to invention of lie detector.

Earliest antecedents of modern lie detector come from device that used trial by torture or ordeal. During Middle Ages in the Europe, torture was the practice that rooted from theory that stated - an agonizing body could oblige a lying mind to croak the secret out. But in 1730, this method of torture for extracting the truth from a person made an exit and a new lie detection method took over. Daniel Defoe was the earliest of men to suggest such a method through evaluation of heart rate. In 18th century, the torturous methods declined completely due to continuous campaigns against the judicial torture in the Europe. This humane way of detecting lie through lie detector was accepted by majority during this time.

The evolution of lie detector was slow but was a pioneering invention for the entire mankind. The emergence started slowly with the initial tests for determining the physical responses during act of deception. Cesare Lombroso also known as Father of the Modern Criminology was the first one to try of application of science for detecting deception. He made use of device known as plethysmograph that monitored changes in blood flow of person at the time of interrogation.
Another breakthrough came in the year 1897 with development of method to measure galvanic responses by B. Sticker. This method used amount of sweat produced on skin with the help of electric conductibility during the test. And in 1914, breathing rate measurement using the pneumatic tubing was done by Vittorio Benussi. This device was draped around the person’s chest for measuring the rate and depth of breath. Benussi discovered ratio of expiration and inspiration was usually greater at the time of truth telling than lying. This method of truth discovery by Benussi gave an important revelation that it was not just pulse rate, sweat production and the blood pressure that helped in lie detection but the breathing rates too. All these findings amalgamated together formed the modern day lie detector known as polygraph.
Earliest machine that took name of polygraph was originally copy machine invented by John Hawkins in year 1804. Name of the machine simply meant ‘many writings’, originated from Greek, early polygraph allowed users to write with the two pens at the same time, creating duplicate copy. In year 1908, an English doctor named James MacKenzie publicized in ink polygraph invention for monitoring cardiovascular responses of the subject taking blood pressure and pulse.
After a few years, in year 1915, William Marston who was American psychologist, started demonstrated lie detection tests to determine whether subject was deceptive using blood pressure cuffs for taking measurements of the systolic BP at the time of interrogation. He was of the strong view that the interrogation techniques used at conjunction with technology than technology itself that led to detection of lies.
As lie detector captured imagination of public, imitators soon entered the field. A doctor from Chicago doctor, Orlando Scott, endorsed Thought Wave Detector, with claims that it had the capability of tapping electrical current of brain. While suspect squirmed and sweated, a big needle sung forth and backwards between true and false option on a big dial.
Despite of the charlatans like Dr. Scott, lie detector made the headway in search for its respect and acceptance. In year 1923, legal decision barred the tests by lie detectors being used as the evidence in courtroom but at places like factories, government department, banks this magic box carved a place for itself offering an efficient solution for detection.

As you know, to be called the creator of the first lie detector belongs to John Larson . In 1921, he first tested the device that secures the dynamics of the three psycho-physiological parameters - pressure, respiration and pulse. However, up to the ideal of the invention clearly does not hold. This is confirmed by test check conducted by Larson.
Therefore, improvement of the instrument began Killer Leonard , who introduced another indicator, suitable for measurement - skin resistance. This greatly increased the effectiveness of testing. A little later in the list of lock-in data has been entered and tremor (also LA killers).
At the beginning of the lie detector was used for the sole purpose - to identify crimes. Thus, a polygraph test at the Killer were about 2,000 people accused of various illegal acts. This greatly increased the detection rate of crime in the city at that time.
Of course, before the creation of a modern instrument, there were many attempts to modernize the polygraph Killer. Scientists are trying to find a relationship between a lie and a variety of physiological responses. Recorded up to 15-19 indicators. However, specific results are not achieved. Modern detector measures 5.8 reading data.
Today, the development of lie detection is not static, though many argued that a polygraph test gives 100% result. This can be found in the news about lie detectors.
John Larson (1892-1965)
                                                     The killer Leonard (1903-1949)

1 comment:

  1. I am willing to get a self employed test and want to buy a lie detector and want to use it.I want to buy this product from here

    So I want to know the views of other people here do you test a lie detector befor and how do you find it? Results are correct or not? plz guide me. Thanks in advance


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