Wednesday, September 02, 2009


Every time a politician dares another politician to take a lie-detector test to see who is telling the truth and who isn't, I can almost always smell the stink coming out from his motives. As such, I have often wondered why our local authorities, especially the police, rely so much on polygraph tests more commonly known as lie-detector tests in their investigations, particularly of murder cases.

As in the US, polygraphs are useless in court and their results cannot be used in testimonies. Time and again, lie-detector tests have been proven to be far from conclusive and psychologists themselves frown on their use.

A study of the development of polygraphs will show they really cannot probe the twisted emotions of a suspected criminal. They can only measure blood pressure, pulse rate and respiration simultaneously by means of a pneumograph tube around the subject's chest and a pulse cuff around the wrist. Impulses are picked-up and traced on moving graph paper which is driven by a synchronous electric motor. The theory is that respiration, blood pressure and pulse are involuntary actions, not subject to the person's will, yet they are bound up with the person's emotional state. Fluctuations from the norm, generally a heightening of those actions, signify emotional tumult and the police conclude this to be a lie. The outcome of the lie-detector test is dependent on the abilities of the test giver and this is the reason why they have been frowned upon as inconclusive. Our police investigators and lawyers have to stop depending too much on the polygraph test results in the pursuit of their cases.

Hence, Mareng Winnie Monsod's recent interview with a solon would prove one thing: A polygraph's electric motor can simply overheat as it receives more lies than it was originally manufactured to take, if ever he subjected himself to such test.

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