Are Polygraphs legit?

[SeventySeven]

whats your opinion? I now believe these to be inaccurate and not a legit way to test as a friend of mine failed one when in reality he is completely natural( i know some people will think, oh he is just backing his friend, he clearly uses) they let him compete after giving him a physical( looking for gyno, acne signs of AAS use)So if a polygraph can fail a legit guy id imagine they can be beaten as well. He was the best by a mile, would bea WNBF pro but the lesser guy got it because of this incident. They also completely botched the heavy weight class, the clear winner got second i mean any joe schmo would have known( he has long hair tied up , was speculated that this was why) also during call outs they were calling top 6 yet brought out 7 twice to have one guy be completely ignored and just stand there in a relaxed pose as they called places( how moronic they must have felt)

[BendtheBar]

Legit, yes. Perfectly accurate, no. Not that I've read.

Here is a quote on their statistical accuracy. I don't have time to research further, but it seems on par with everything else I've read.

If the percentage of guilty is small, say 5 percent (1 guilty person out of every 20 persons screened, or 50 out of 1,000), then even assuming a very high (95 percent) polygraph validity rate, the predictive value of the screening use of the polygraph would only be 50 percent, That is, for each 1,000 individuals screened, about 47 out of the 50 guilty persons would be correctly identified as deceptive, but 47 out of the 950 innocent persons would be incorrectly identified as deceptive (false positives). Thus of the 94 persons identified as deceptive, one-half would be innocent persons. For every person correctly identified as deceptive, another person would be incorrectly identified.

If he agrees to take one, then he pretty much agrees to deal with the outcome.

Can I ask your friend's height and weight from last night's show? I am simply curious where he falls compared to predictive natural standards and against other top natural bodybuilders.

[gaspers04]

We use em for investigations all the time. The offender goes in thinking that hes a great hustler, bombs the test, IA starts drilling him and then he begins sings like a .....jail bird.

[Rich Knapp]

Your freind is lucky they let him compete after a rinky dink physical as they don't proove a thing. INBF/WNBF has a 100%, no tolerance. If he won then he would have been piss tested. They may have helped him save face. Sorry 77 but even the closes freinds don't know a freind that cheets.

Keeping there mouth shut is part of the challenge of cheeting. Untill the piss test.

Polys catch 75% of the lower quality cheeters and the piss test catches the other 20-25% of them. But even at that people will use and get popped still cry they are clean.

Best way I have found is to never ever ever put your self in a spot were you do need to play the system or pray you get popped.

Point blank, if your 100% clean do a tested show, if your not just do a non tested show and don't even try to cheet. Thats kind of a no brainer.

[JacktheThriller]

They work well if people don't know what it measures. How the machine gets it readings.

[SeventySeven]

BTB he is 5'11 weighed in at 172.

Rich,i agree with you but my friend is not a cheater.

Once i get some pics i'll post them up.

[BendtheBar]

Originally Posted by SeventySeven

BTB he is 5'11 weighed in at 172.

Certainly nothing unusual about his weight then. I know it must be hard for him.

[ricka182]

Yes, legit. No, not the most accurate. Yes, beatable if you know how. I've never had one, but I know someone who did pass a poly, even when the detective knew he was the guy, but everything was circumstantial so they had to let him go. Wasn't worth chasing a case for egg throwing..

[Tannhauser]

If you think about how they work, there's a fundamental problem. The assumption is that lying is inherently stressful, and this will be revealed by a stress response. That stress response is detected by changes in skin resistance (through sweating), changes in heart rate etc.

BUT

Being asked emotionally charged questions (such as 'did you take drugs?') is itself stressful. The feeling that you might be wrongly accused of something, that the test might fail could also trigger a stress response.

Also, what happens if lying just isn't stressful for you? It isn't for everyone.

As a technique for getting to the truth, is it much better than torture? I don't mean morally, just in terms of accuracy. Both probably throw up lots of false positives i.e. they set the standard of evidence pretty low.

Loads of countries won't use polygraphs for evidence for just that reason.