Monday, December 2, 2019

Polygraphs Essays - Polygraphy, Pseudoscience, Polygraph

Polygraphs Introduction Homo Sapiens have yearned for a reliable and consistently correct way of finding out if one is telling the truth since ancient times. ?Early societies used torture. Statements made by a person on the rack were considered especially believable.? (Jussim, pg.65) There was also trial by ordeal, which was based on superstition. For instance, if there were two suspects for one crime, it was thought that the innocent would be stronger in combat and thus vanquish a guilty opponent. This example shows how it was done long ago. ?The ancient Hindus made suspects chew rice and spit it into a leaf from a sacred tree. If they couldn't spit, they were ruled guilty. Although this procedure long predated the modern lie detector, it was based-knowingly or not- on assumptions about psychological stress much like those that support polygraph examinations today. The ancient test depended on the fact that fear makes the mouth dry, so rice would stick in a guilty person's mouth. For the procedure to work, the subject had to believe in its accuracy and, if guilty, had to be anxious about being caught in a lie.? (Ansley, pg. 42) The modern polygraph is said to measure the subject's ?internal blushes? in much the same way. It does not really detect lies-only physiological responses. The theory behind the polygraph is that lying always heightens these responses. When taking the test, subjects are hooked up to a briefcase-sized machine by means of several attachments. usually, a pneumatic tube goes around the chest to measure respiration, a cuff squeezes one bicep to monitor blood pressure, and electrodes are attached to two fingertips to determine the skin's resistance to electrical current (which is related to how much the subject is sweating). An examiner, or polygrapher, quizzes the subject. As the subject answers the questions, the machine draws squiggles on a chart representing physiological responses, which are supposed to clue the examiner in to the subject's lying, or truthful, ways. Just as the ancient Hindu was betrayed by a dry mouth the modern polygraph subject is said to indicate that he or she is lying by breathing harder or having a racing pulse. (In arriving at a conclusion about a person's deceptiveness, some polygraphers also use their own subjective observations of the person's behavior.) The test will not work, though, if the subject does not believe in the procedure. If the subject doesn't not think the machine can tell the examiner anything, then he or she won't be anxious and won't show the heightened responses that the machine is designed to record. Because of this, the examiner will often use deceptive tricks to impress the subject with the polygraph's alleged accuracy. Modern polygraphy got its start in Chicago in the 1930s, where it was used in criminal justice investigations. Now it has a wide range of other applications, including screening job applicants and employees, conducting intelligence investigations in federal security departments like the Central Intelligence Agency, and trying to uncover the source of unauthorized disclosures to the press of government documents or information. The strategies used by polygraphers vary from one application of the machine to another. in pre-employment screens, subjects are typically asked a series of about twenty questions. ?Irrelevant? questions like ?Is your name Fred serve to put the subject at ease. Typical ?relevant? questions are: have you ever been convicted of a crime? Stolen from a previous employer? is all the information on your employment application correct? Do you take illegal drugs? This series is repeated, and if physiological responses to particular relevant questions are constantly and significantly higher than responses to others, the subject is reported as ?deceptive.? Investigations into specific incidents are more complicated. Tin these, ?relevant? questions concern only the alleged wrong doing-for instance, ?Did you steal the missing $400 To determine truthfulness, polygraph responses to these questions are compared with responses to other questions- called ?control? questions-that are provocative but do not relate to the incident. The use of polygraphs in the work place greatly increased over the last fifteen years, and now over two million of them are given annually in the United States. Seventy-five percent of them are administered to job applicants. Other tests are given periodically or randomly to employees or as part of an investigation in the wake of a theft or act of sabotage. Although subjects technically submit to testing ?voluntarily? - generally signing a release saying they are willing to undergo such an examination- they actually have few options. Applicants who refuse a

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