The Home Lie Detector

I have mentioned before that I am on the mailing list of Hammacher Schemmer, the store that has sold the best, the only, the unexpected,and the absurdly expensive for the last 166 years. In a recent catalog, I spotted a must have item, the home lie detector.

This is the USB lie detector kit with digital pulse and skin monitors for conducting a polygraph test at home. Using sensors applied to a subject’s fingers, the system takes baseline readings of the pulse rate and the skin’s electrical resistance and measures any changes in response to questioning. Data is graphed and stored in real time using free software, so testers can assess whether the subject’s pulse accelerates or the conductivity of their skin begins to change—the same physiological signs that professional polygraph examiners use to determine whether a suspect is lying. Although results are not legally binding, they may provoke a teenager’s confession about sneaking in after curfew or simply elicit laughs at a party. The system connects to a computer using the included USB cable. For Windows 8,7, Vista, XP, and Mac OSX. Box: 8″ L x 6″ W x 4″ D. (2 lbs.)

HLD

 

This can be yours for only $399.95.

There is, of course, not really any such thing as a lie detector, at least not in the sense that there is actually a machine that can determine if a given statement is truthful or not. What is often called a lie detector is, in fact, a device called a polygraph.

A polygraph operates by measuring various physiological processes, such as pulse rate or the skin’s electrical resistance, as mentioned in the catalog, and perhaps respiration and blood pressure depending on the device. The theory is that these measurements change when the subject is telling a lie.The extent to which this theory is valid is unknown since there doesn’t seem to be any consensus on how effective the device actually is. Professional polygraphers and their trade associations claim a better than 90 % effectiveness. Others, including the American Psychological Association are skeptical about whether the device is effective at all.

It is not quite true that the results of a polygraph test are not legally binding. That actually varies by state in the United States. Something like nineteen states do admit polygraph results as evidence, depending on circumstances. Polygraph evidence may also be admitted in a Federal trial, if the presiding judge at a court permits it. In general the results of a polygraph test can only be used in court if both the prosecutor and the defendant have no objections.

Since every individual responds to stress or lying in a different way physiologically. no polygraph device can determine if a person is definitely lying or telling the truth. No such device has a button that lights up or a alarm that sounds if a lie is told. The results of a polygraph examination must be interpreted by the examiner, and this is why there is so much uncertainty concerning the effectiveness of the polygraph is at detecting lies. The usual procedure is for the examiner to ask a series of innocuous questions to the subject being tested in order to establish a baseline for the various physiological processes being measured. Once that is done, the examiner can proceed with the actual interrogation of the subject. Even then, the results are far from being unambiguous and determining whether a subject is being honest is more an art than a science. A good many polygraph examinations end up being simply inconclusive. I suspect that in the cases in which a polygraph examination is effective at detecting lies, it may be more because the subject believes the polygraph to be effective and is more nervous about lying than he otherwise should be.

It occurs to me that a person who is knowledgeable about the workings and actual effectiveness of a polygraph would be more able to cheat the device than someone who really believes it can detect lies. I would also imagine that an experienced liar or criminal would display less of the reactions tested than a person who is naturally honest. It may well be that the honest, law abiding citizen, or the inexperienced and perhaps guilt ridden criminal would have more to fear from a lie detector test than the career criminal used to lying, or the sociopath who believes there is nothing especially wrong with lying. It should be noted that the notorious traitor and spy Aldrich Ames passed two polygraph examinations with flying colors while he was passing information to the Soviets, as did Gary Ridgeway, the Green River Killer. There have been suspects who have failed polygraph examinations only to be exonerated by actual evidence.

If you are ever asked to submit to a polygraph test as part of a criminal investigation, you should refuse unless your attorney is present. The police cannot force you to submit to a lie detector under any circumstances and you should not be certain that the results of such a test will show you to be innocent. You also cannot be required to take a polygraph test as a condition of employment by most private employers, the exception would employers who work with the government and have access to classified materials. If you apply for a job and are asked to submit to a polygraph test or if your employer asks you to take an exam as a condition of continued employment, chances are they are breaking the law. You might want to consider whether you want to continue working for someone who obviously mistrusts you.

So, if you want to have fun at parties, by all means buy the Home Lie Detector. I wouldn’t recommend you use it on your teenager or anyone else. If even people who administer polygraph tests professionally can sometimes find the results difficult to interpret, you might not want to be too confident of your own, or the computer’s interpretations. And, forcing your child to submit to a polygraph test might not be the best way to build trust in a relationship.

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