People put so much faith into them. But they're horrible tools that are horribly inaccurate. I see in the media people make a big deal about people passing or failing a lie detector as if it's the word of God himself. This is ridiculous! In 2011 studies showed that lie detectors are right 85% of the time if the party was guilty. That's pretty bad. That means 15% of guilty people can pass the test. What's worse is that only 60% of INNOCENT people can pass the test! Say it's nerves or whatever. 40% of INNOCENT PEOPLE fail lie detector tests. That means if you flip a coin you have almost as good of a chance of being found guilty in a lie detector... while INNOCENT... Lie detectors should never be used. They screw innocent people. They aren't effective enough at finding the guilty. I'd be fine with it if people took them with a grain of salt but they don't, most people including law enforcement and the media think or portray it as a definite. It's already inadmissible in courts but they use them anyways. Juries are ordered to take them not so seriously but imagine how many times they do anyways. And cases have been won or lost or dropped or raised ONLY because of lie detectors. A tool that's like 70% correct... Even the fancy ones that scan your brains are horribly inaccurate...
Actually, I would like to see wearing of lie detectors as part of official Congressional garb, but with the thing wired to goose the Congress Critter every time they lie...
Interesting post MG, thanks. To my knowledge, no one (in the U.S.) is compelled by law to submit to a polygraph test.
Politicians lie so convincingly it would likely do nothing. Lie detectors work by measuring reactions to lies; if you lie all the time these reactions are likely to go away. Rather than get that strange feeling of nervousness, hoping the lie will be accepted, lying becomes just like talking normally.
They're not but I do believe it is admissible evidence. It's also used in high security government jobs.
At least in Colorado, where I worked, the results of a polygraph was only admissible as evidence if both the prosecution and the defense stipulated before the test was taken that it would be admissible. I think polygraphs are unreliable but not as unreliable as eye witnesses.
Eye witnesses are more relevant to the system though because they actually saw the crime. These machines and interviewers simply watch a person. The key to telling if someone is lying is if they're nervous. Factors like heart rate, sweat on the palms, shaky voice, etc are taken into account. Well there's a few problems there. First off the machine just monitors stuff; it's up to a person to interpret what's actually happening. Humans are far from infallible. Second if someone is nervous they're going to give out guilty results whether or not they actually are guilty. Third there are ways to cheat the machine. One method is apparently to clench your ******** then release when answering the questions. This will make the machine register you as calm. I guess what I'm saying is that just because one thing isn't very good isn't a reason to allow for another thing that isn't very good.
I'd trust an eye witness before a lie detector. Easily. At least there you can examine their histories and deem if they're to be trusted or not. With a lie detector it's pure chance.
There are only 19 states where a polygraph test is admissible as evidence but only if both sides AND the judge agree. In 1998 the Supreme Court ruled them unreliable and left the decision for their use to the states. A dishonest person can trick a test into saying they are telling the truth while a nervous, honest person can have a false positive.
In the eyes of the defense and the prosecution...an eye witnesses is both lying and telling the truth simultaneously..... I have a friend who works with the DA's office, and he swears by the lie detector, plus he also likes it for the intimidation factor. Back in the day...the bible and a little swearing used to do the trick. I think politicians should have to wear them when they are debating...wouldn't that be fun!
I'm literally one of the most law friendly people around. I've got little to hide and nothing I have to hide is illegal. I'd be afraid of false positives. I mean there's a 40% chance of it happening! Your friend hasn't looked at the numbers.
Oh, right. They're right up there with people who see UFOs and aliens abducting their family. If you're interested you can read research by Loftus and Loftus and find out the reliablility of eyewitnesses. I love all your technical details. It's a shame you don't know what you're talking about. Do you post here with your (*)(*)(*)(*)(*)(*)(*) clenched? Since, polygraphs are rarely used in court, it's really not a significant issue. Eyewitnesses have put a lot of innocent men in prison.
Then you should read some research. Oh, wait, liberals choose emotion over science. Nevermind. I do not believe polygraph results should be used in court but of all the problems besetting this system, this one is truly insignificant. Here's an interview with Dr. Loftus from a source that excites liberals. http://www.pbs.org/wgbh/pages/frontline/shows/dna/interviews/loftus.html
