Lie detectors

lie detectors can only catch u when uu say something in fear,if u say in normal i mean if ur blood speed goes normal when you are talking then it is impossible to catch a person .....its only depend on your blodd speed and heart best during your talking(lie or truth)what ever it is .,

I've heard of people who could beat the test by controling their breathing.So if you truly believed what you were saying was true and your breathing was relaxed,I'd say yes.Or at least it would come up inconclusive,which wouldn' confict or clear you.Interesting question.I gave it a +.

Zubair is right it is to do with blood pressure, if a person is lying there blood pressure, or beats per minute do go up slightly, so a person who didn't know they were lying probably wouldn't be caught by a lie detector because their blood pressure/bpm wouldn't go up at all.

I do not believe in lie detectors...:p, I also don't get how a machine can see if you are lying actually

a lie detector is not normally 100% correct because it can be fooled. the detector mesures you heart rate, and when you lie, your heart rate goes up, if you can keep your heart rate from altering, then you can fool a polygraph. the thing they're reaserching on now is the MRI method, they scan your brain while asking questions..since the brain needs to think to lie, it will notice it better, in initial tests it showed to be a lot more accurate then the polygraph, but it needs more testing before it can be used on the public.

What if you are nervous anyway and telling the truth?? Those things aren't always reliable..

Apparently a lie detector measures pulse and other reactions common in people under stress or people who are lying. If a person thought that what they were saying was true, then the lie detector would show that they were telling the truth.

not always do they work though

there are problems with the polygraph, i lie isnt a lie if someone believes it to be true, its a mistake a polygraph test will not pick that up. However it can be cheated, a polygraph (lie detector ) works by picking up on changes in your anxiety levels, security workers know when being questioned to deliberatly increase their levels of anxiety before the test and therefore invalidate it

yes lie detector is connected to the deep mind of the patient when he lies his activities inside the body may changes abnormally then it detected

lie detectors work on a principle of how the brain responds to your questions sometimes nervous people end up with false charges....lie detectors aren't fool proof...convicts force themselves to believe that what they are saying is true and end up fooling the machine a good way to detect a person is took to look at his pupil...but you can't do that in public lol....look up body language signs such as a person lying nerver looks in the eye and speaks,his body isn't nervous if he's been lying for quite a while....

I think u have raised a good point It detects only the sensations r the nerves they can be fooled easily

I do belive that u can cheat a liedetector, that´s why they are not aloowed to use as HARD evidence during a trial. I do also belive that if u have no memorie of the event that you will pass!

well honestly i dont believe in lie detectors. i know one person who undergo that. she was telling the truth.we both know she was . but the result was that she was lying. maybe because she was just nervous. its not effective in my opinion.

If a man having high will power and expert in acting a drama, Surely he can over ride the capability of lie dectoters

I have absolutely no confidence in the effectiveness of a polygraph. The process is totally unreliable and depends on the reaction of the individual to the questions asked. The basic principle of a polygraph depends on the person's reaction when telling a lie, but is subject to 2 problems. Firstly, a self disciplined and confident person can beat the machine, as has been shown many times in the past. Secondly, how many people would react nervously when asked "Did you murder him?". I believe that many people would react differently to such a question than they would to "Do you like coffee?", especially when the answer is so important. As for the factor of believing that you are telling the truth, this would certainly affect your results.

Polygraphs and lie detecters are all crap. That's why they can't be used in court/at trial. They're just a tool the police use to help their investigation. I've taken different ones, and the thing said I was lying when I told the truth and said I was telling the truth when I was lying lol.

The lie detector detects tiny involuntary reactions to questions being asked. Also, when a person knows they are lying, they may show these involuntary signs when doing so, things they can't control like their sweat rate and heartbeat. If a person believed what they were saying, even if it was a lie, it will still more than likely go through the lie detector as truth, because they signs of 'lying' would not show if they honestly believed what they were saying. However, lie detectors are not foolproof. Hope this helped.

Yes, I got your point. Lie detector may be manipulated by person because it is best on nerve response and emotion. In the Philippines, we do not honor lie detector in court. Second, lie detector findings is not conclusive. It will give us reports in theres of graph and changes but it doest tell us whether it is lie or not.

I don't trust those things. I have seen people that were too good at lying. I think they could get around it. I've also seen people that are anxious and nervous but truthful.