Everyone knows the polygraph is an inexact tool, at best. That includes Islamic extremists, too.According to the lie detector skeptics over at AntiPolygraph.org, this article, published in a jihadist magazine and on an Al-Qaeda affiliated site, tells Islamic extremists how to beat the machine. So why does "the U.S. intelligence community continues to place great reliance on polygraphs in assessing the credibility of prisoners, agents, informers, and even its own employees?" AntiPolygraph asks.
...The control questions are a group of questions that the interrogator asks the mujahid and the answers to which are known by both parties. The interrogator presents these questions to the mujahid and asks him to answer them, and meanwhile, the device records what are considered the natural heart, blood pressure, breathing, and perspiration rates, which will be compared with those that will be recorded during the real interrogation questions. If the mujahid is upset during when answering the interrogation questions, these physiological rates will change, and that will be considered an indication that he is lying.If you know this, my brother mujahid, then you know that the control questions are among the most important stages the mujahid undergoes during interrogation with this device, and he must know how to deal with them as will be explained shortly.The first thing that must sink into the mujahid's head is that the aforementioned physiological changes can occur for reasons other than lying such as nervousness, anger, sadness, embarrassment, fear, relaxation, and so forth. Cold, headache, and constipation may also cause changes in them. All this greatly diminishes the importance of the test results.And don't suppose that experts can tell the difference between changes caused by lying and changes caused by other factors: up to now this has not been proven.In many tests, truth-tellers fail and liars pass. Some people may show symptoms such as fear, for example during the test, and so the device indicates that they are telling the truth [sic] even though they are honest. And many liars pass the test...Researchers have been scrambling for years to build a better alternative to the standard polygraph. So far, the results haven't been particularly encouraging.