How Accurate Are Polygraph Tests?


3 Answers

Christopher Profile
Christopher answered
Polygraph tests are most often administered by American police officers and investigators, in order to determine if a suspect's testimony is true, or if he/she is lying. These tests are occasionally even used to force suspects to confess to crimes. Although lie detector tests are far from perfect, they take note of a suspect's physical responses--such as blood pressure and heart rate--to see if he is being truthful. When someone lies or deliberately passes on misleading information, their blood pressure, heart beat, breathing or pulse may change very suddenly, as a sign of discomfort and nervousness.

According to recent police estimates, polygraphs are accurate approximately 90% of the time. Some law enforcement officials claim that the accuracy rate is closer to 95%. Over the past decade, these lie detector tests have even been used by popular afternoon talk shows, such as the Maury Povitch Show, where the host would arrange to have it administered in order to see if a wife or husband was cheating on his/her spouse.

There is, however, a major disagreement between law enforcement officers who believe the accuracy rate of polygraph tests stands at 90% and many scientists, who claim that it is closer to 61%. A total of 421 psychologists participated in this study, back in 1997, and they aimed to show that polygraphs were much less accurate than what police officers would like to believe.
Angel Frank Profile
Angel Frank answered
I do not believe personally that they are very accurate from personal experience. There was one brought to our high school and we volunteered for it. I gave wrong answers deliberatly and the lines told a different story of it being the truth. It was really wierd and since then I do not trust them.
Arthur Wright Profile
Arthur Wright answered
Only as accurate as giver but reason why many courts don't recognize them as the evidence used for them is hard to really verify. I don't trust them and I has classes in them

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