{"id":4733,"date":"2016-04-04T10:47:41","date_gmt":"2016-04-04T15:47:41","guid":{"rendered":"https:\/\/content.findlaw-admin.com\/ability-law\/smallbusiness\/employment-law-and-human-resources\/lie-detector-tests.html"},"modified":"2024-06-06T04:46:39","modified_gmt":"2024-06-06T09:46:39","slug":"lie-detector-tests","status":"publish","type":"page","link":"https:\/\/www.findlaw.com\/smallbusiness\/employment-law-and-human-resources\/lie-detector-tests.html","title":{"rendered":"Employee Lie Detector Tests"},"content":{"rendered":"\n
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Employee Lie Detector Tests<\/h1>\n
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\n By Susan Buckner, J.D.<\/a> | Legally reviewed by Aviana Cooper, Esq.<\/a>\n | Last updated\n
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The polygraph examination, popularly called the "lie detector," is an arbiter of truth by employers and law enforcement in America. This is in spite of the fact that polygraph exams<\/a> are not accepted as evidence in any court aside from New Mexico. They are generally unreliable for assessing whether someone is lying or telling the truth.<\/p>\r\n

The American Polygraph Association<\/a>, considered the leading training and accreditation agency in the world, states that polygraph equipment is seldom more than 80-90% reliable. A background check or pre-employment screening test is equally reliable for assessing an applicant’s honesty and reliability.<\/p>\r\n

How the Polygraph Works<\/h2>\r\n

Despite the popular name of lie detector, a polygraph cannot tell if someone is lying. The machine measures four to six physiological responses, such as respiration, blood pressure, and heart rate. The theory is that lying causes stress reactions, which a trained examiner analyzes.<\/p>\r\n

A polygraph exam takes about an hour and a half to two hours. The examiner interviews the subjects to understand their speech patterns and reactions. It also helps the subject get comfortable with the examiner so that simple nervousness does not affect the test. <\/p>\r\n

The examiner puts the measuring equipment on the subject and begins the exam. The examiner marks the graphs when they ask a relevant question. Any significant change in the measurements is taken as a sign of stress and an indication of lying.<\/p>\r\n

How the Polygraph Does Not Work<\/h3>\r\n

According to the American Psychological Association<\/a>, polygraph examiners conduct tests in two different ways. The standard method is the control question test, where they ask subjects several innocuous questions and then a relevant question. Truthful subjects have less anxiety about relevant questions because they know they are innocent of the alleged crime. The guilty knowledge test asks questions that only someone with actual knowledge of the crime would know.<\/p>\r\n

The difficulty with assessing either test is that polygraphs have not been, and possibly cannot be, tested in any way to determine if they are testing a valid physical response. The accuracy of any given test may depend as much on the subject’s belief in the test as it does on the test itself.<\/p>\r\n

According to the American Psychological Association, "Research on the processes involved in [control question test] polygraph examinations suggests that several examiner, examinee, and situational factors influence test validity…There is little research on the effects of subjects’ differences in such factors as education, intelligence, or level of autonomic arousal."<\/p>\r\n

The Employee Polygraph Protection Act<\/h2>\r\n

These doubts and conflicting reports led to the passage of the Employee Polygraph Protection Act (EPPA)<\/a> in 1988. This federal law prevents the use of lie detectors for pre-employment screening or for using the results against workers in employment. Small business owners may not<\/a>:<\/p>\r\n