Truthful and Faithful

Friday, October 12, 2012


Dear Patrick: My husband is truly insecure. He has been cheated on in every other relationship. When he started to suspect me, I was very hurt. I have never cheated on him (or anyone else). I have a very strong moral belief about this. Once you are with somebody, you are with them; there are no excuses for going outside the relationship! He asked me to take a lie detector test. I thought this would be a simple way to resolve things so that he would trust me again. Well, I failed the lie detector test, and now it looks like he will be talking to a divorce attorney. He has moved into the spare bedroom and will hardly even talk to me.

    I am devastated. The test is wrong. I don't think I've even flirted with another man. If he knows me shouldn't he also know that I am true to him? But then how could I fail the test? I am so confused, I don't know what I should think or what I should do. Can my marriage be saved?--


Lie detector tests are notoriously unreliable. It's estimated that anywhere from 5-40% of the people who take these tests are falsely accused of lying. A 2003 review by the National Academy of Sciences was highly critical of these devices.

          The polygraph was supposedly invented by a man who believed that blood pressure goes up every time someone tells a falsehood. This basic assumption has never been validated by medical or psychiatric research. Nevertheless, the modern polygraph measures things like your heart rate, breathing, blood pressure, and sweat. The operator may have received only a few weeks of training. There's no universally recognized system for licensing polygraph operators, and interpretation of results is highly subjective. The idea is that by asking you a set of questions with known answers (the “controls”) and recording a baseline set of physiological responses, the operator can then ask you questions with unknown answers. If any of your physical signals change, the assumption is that you are lying.

          Unfortunately, the control questions are not standardized. There is no set of control questions that research has demonstrated to be universally useful. For example, it's common to ask someone if they ever drove while they were intoxicated. The assumption is that everyone has done this. A person who says no is assumed to be lying. An operator might become angry and even abusive if the test subject doesn't give them the control answers they expect. I have often heard that the polygraph is a useful tool in the hands of an experienced operator, but this is a terrible argument for its worth. We can contrast this with a blood test for paternity. It yields the same results every time. Consistent, repeatable results are the hallmarks of a valid test. We have no way to objectively measure what might make one person an accurate administrator and another person a poor one. You are at the mercy of whoever sits behind the laptop, staring at the numbers.

          It's repeatedly been demonstrated that some people have the ability to fake out the polygraph. Some people simply don't care if they tell the truth or lie, and they may be able to relax so much that there are no perceptible differences. Pushing your feet onto the floor or clenching your fists may alter readings. Several medications can also affect the results. People who have issues with anxiety will frequently get a false positive just because being tested makes them feel stressed and upset. This may be why you were slandered by the test you took.

          Sadly, thousands of people have had their careers irrevocably damaged because polygraph tests are used to screen applicants for law enforcement and government jobs, and even some jobs in the private sector. They are also used during interrogations by police departments even though the results are rarely admissible in court. You might enjoy reading a couple of pieces of investigative journalism about the quest for a way to automatically detect falsehoods. One is “Lie Detector Roulette” by Brendan I. Koerner, published in the November/December 2002 issue of Mother Jones. Another is Jennnifer Granick's March 15, 2006 article for Wired entitled “The Lie Behind Lie Detectors.” You might find some valuable support from the website, reportedly founded by a man whose career was needlessly ruined by this ridiculous piece of chicanery.

          If you share this information with your husband, he might get off his high horse and decide to apologize and cancel his appointment with a divorce attorney. But you ought to ask yourself if you want him back, Truthful and Faithful. It's worth asking if all of the women he's accused of cheating on him were actually guilty. Or is he a controlling and paranoid person who likes to harass his partners and keep them in a state of tension and fear? Being with a person who can't trust you is hard on the nerves, and puts unnecessary distance into the partnership. So I hope you will see a counselor and evaluate your marriage and your husband before you go for the quick fix.

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