Polygraph tests often aren't admissible in court because they can't actually detect lies, but instead physical indications that often accompany them. Your intentions aside, it's good to know how to beat the polygraph to ensure it doesn't mistake anxiety for untruths.
It's Evil Week at Lifehacker, which means we're looking into less-than-seemly methods for getting shit done. We like to think we're shedding light on these tactics as a way to help you do the opposite, but if you are, in fact, evil, you might find this week unironically helpful. That's up to you.
AntiPolygraph.org is a site dedicated to exposing the truth behind the polygraph. While that kind of statement sounds like it's out of the mouth of a conspiracy theorist, and the site is a little on the extreme side of the spectrum, polygraphs are not true lie detectors. What they generally detect is the person's breathing rate, pulse, blood pressure and perspiration — all things that can be erratic regardless of whether or not the person is lying. Here's how to beat it:
One of the first suggestions is constricting your anal sphincter muscle. It sounds strange, but it actually helps raise your blood pressure. When you answer a control question for the lie detector test and your blood pressure is high, if it happens to be high when you answer a regular question this will look more normal and render the test inconclusive. Another technique that (probably) does not involve your anus is thinking exciting thoughts. Imagine the experience of skydiving, for example. Pretty much anything that will get your heart racing will do.
The problem is, these are very simple tricks and an experienced polygraph tester is likely to notice the use of these countermeasures. It becomes especially evident when measure your perspiration, because that's the hardest thing to fake. So what do you do? It's much easier to fail a lie detector test when you believe it's infallible. If you can convince yourself it's not, you'll have a much easier time fooling it.
Your best bet, however, is refuse to take the test. We're often led to believe that not taking a polygraph is akin to an admission of guilt. That's not the case. While polygraph tests are administered for a number of reasons, if you end up going to trial your choice can't be used against you. Whether you're lying or not, the polygraph isn't perfect and can guess wrong. There's really no sense in taking that chance if you don't have to.