Lie detector test results,Accurate?

Question

I need to convince my sister who may be believing the sorry #@$@# who failed it,concerning her children.Any proof that results are accurate would help.

Answer 1

The name of the machine is a polygraph. What it does is measure 3 (poly-which means many) different "graphs" (breath, heart rate and galvanic skin response) of a person who is being asked a series of questions. There is NO machine that can tell what is a lie and what isn't. The machine only measures a persons body response to a question. There have been many studies done on the accuracy rate of the tests and they seem to be correct 80 to 90% of the time. The problem I have with that is what about the 10-20% of the time that they aren't accurate. I guess that is why the results aren't admissible in court.

Many evaluations have concluded that polygraph results are more likely to be valid if they show innocence than if they show guilt. This is because there are lots of situations where a defendant may have a guilty mind (and thus show up as deceptive on the polygraph results) but not in fact be guilty.

I see that you are dealing with a very serious issue with your nieces/nephews. So I would say irregardless of the results of any polygraph if you or your sister feel there is even a remote possibility that something is going on then they should never be left alone with who ever it is.

Answer 2

Lie detectors are not accurate. Think about it, if someone knows along the lines of what questions are to be asked, they are already prepped for it. Certain tests asks you the same question 3 times. So you have 3 chances of beating the test. Nowadays they have the computerized test that I think is the worst way of determining any changes in breath, skin density, and or heart rate, etc.. So it depends on how many chances the person has at beating that test if the questions are asked more than in one round. If not more than once then I suppose the least amount of chances that individual has. I have personal experience that I will not go into. Im not going to say I was not telling the truth, and im not saying im some expert at lying. Just know some people are in more control of themselves and technology.

Answer 3

Yes & No.

If a person TRULY believes that they are telling the truth, then the lie dectecter will see as is; that they are being truthful.

However, most of the time, a person is so nervous about taking one, they don't realize how their internal body is going to react to the questions they are being asked.

I went through a test for a job with the police department, they have you answer a question incorrectly so they are able to decifer if you are telling the truth throughout the rest of the test.

If I were your sister, even though I don't know all of the facts, I would go & get a second opinion, because they never hurt :)

Good Luck!

Answer 4

Polygraphs, a.k.a. Lie Detectors are terribly inaccurate as the ultimate decision as to whether someone is lying or not is left up to the examiner. And believe me, I've met some polygraph examiners who were suckers. No, they are NOT accurate and I would NEVER base a tough decision on their results.


NOTE: Regarding Kinkyboot.... above my answer, said user pointed you to a site where polygraph examinations are being sold. Naturally their literature would claim that polygraph examinations are close to 100% accurate. I can tell you with 0% doubt in my mind, they are inaccurate. While there may be some benefit in regard to soliciting a confession as a result of the intimidation factor of the ignorant, in reality, they are fancy pseudo truth detection devices. In short, they are worthless. Might as well call a psychic hotline.

Answer 5

They are fairly accurate for MOST people. Those who have been trained to fool them, though, can do so. So can people who have naturally low blood pressure.

I've had biofeedback training and have naturally low blood pressure. I took a lie detector test because of a work issue and was accused of manipulating the results because the technician was having trouble picking anything up - they expect everybody to be nervous and have elevated pulse/BP/etc. and I was focusing on NOT being nervous.

However, if this guy hasn't had that kind of training and isn't usually pretty calm, I doubt that would be the case for him.

Answer 6

The way a lie detector works is the body reacts if you lie then the machine picks up that your body is reacting. The reason it cannot be used in court is although it is accurate if someone really believes he is right although it is a lie the body will not react normally so it is not fair to base someones life or imprisonment on that but it is safe to say it is pretty accurate

Answer 7

Some people know how to beat the lie detector test so it is not 100% accurate. However, because some people are nervous about the specific question they are asked because they know that they are about to tell a lie, they fail it.

Answer 8

People tell lies and deceive others for many reasons. Most often, lying is a defense mechanism used to avoid trouble with the law, bosses or authority figures. Sometimes, you can tell when someone's lying, but other times it may not be so easy. Polygraphs, commonly called "lie detectors," are instruments that monitor a person's physiological reactions. These instruments do not, as their nickname suggests, detect lies. They can only detect whether deceptive behavior is being displayed.

Answer 9

If you are a calm person that does not fold under pressure you could pass a lie detector test no matter how guilty you are. On the other hand if you are nervous and jittery person it would be hard to pass one at all.

Answer 10

For most normal people it's very accurate. People with nervous disorders or some other medical conditions can produce false indications of deception. This is why it's not allowed in a court of law.