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Challenging The 'Unbeatable' Polygraph
George Maschke writes "Dr. Louis Rovner, a prominent California polygraph operator, has (through PR Newswire) issued a press release titled, 'Polygraph Unbeatable, Says California Psychologist.' All too often, such publicly-made claims by those with vested interests in the perpetuation of polygraphy (a make-believe science that offers make-believe security) go unchallenged. So, I've publicly challenged Dr. Rovner to support his claim and pointed out scientific research that contradicts it, as well as the examples of several notorious spies and a serial killer who have beaten the polygraph. See, A Public Challenge to Dr. Louis I. Rovner."
As I read it he isn't claiming the polygraph to be 'unbeatable' and concedes that some people may be able to beat it but most can't and certainly not by reading a book. More importantly, who cares? Last time I checked polygraphs are generally inadmissible by law.
Yes. I mean no. I mean... I think I'm not sure. Well but... Maybe... Well if you put it that way... erm. No? *BBBBBBBBZZZZZZZZZZZZZZZT* "What is your favourite color?" "Blue! ... No Red!"
"Aaaaaaaaaahhhh..."
Otherwise, I'd be good.
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"Overall," says Dr. Rovner, "we are confident that polygraph tests have a 96% accuracy rate when done properly."
If that is true, then if you have 1 spy and 49 honest people, this polygraph will likely falsely accuse two honest people as being spies.
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Most polygraphs work on the idea of remorseful feelings the subject will have if they report a lie in response to a question. Indeed they are beatable - most murderers and other criminals would not give off remorse when asked questions, thus the machine interprets the response as the "truth". This is the main reason polygraphs cant use these results in court.
Thus, when polygraphs are used, it's important it _not_ be the only tool used. For instance, when the USGov't investigates someone applying for a security clearance, they check everything in addition to using the poly. Credit history, school records, school/military diciplinary records, tax records, medical history, family medical history, they perform various psychological exams, they talk to the guy's friends and co-workers and supervisors, and so on. They ask questions about international travels, friends who are non-US citizens, etc.
This way, when someone "passes" a poly, there's evidence to back that up or refute that result. If the investigate report backs up a positive polygraph result and nothing negative is found (or the negatives are manageable), then the guy can probably be given that clearance. Otherwise - the red denied stamp gets pulled out. Indeed, someone can pass the poly and still be denied the clearance - such as a black eye on the credit report (espionage risk - if the guy falls behind on mortgage payments, he could sell secrets to whomever wants them) or a history of alcoholism (clumsiness with classified material risk - if the guy gets drunk while acting as a courier, he risks losing it).
ok, this is a little OT, but i thought it was fascinating enough that i'll post it anyway.
So a few weeks ago, I was driving back to school late at night and was listening to Art Bell (yes, its full of wackos but it's entertaining. Been listening since 7th grade)
Anyway, there was this guest on about polygraphs and plants, yogurt bacteria, eggs, food, etc.
Basically the guest said that if you hook up a polygraph to various "living" things, you can get some sort of reading off of them. If you put stress on/around the thing being monitored, it will react.
For example, if you hook up a polygraph to an egg, and have a dozen other eggs around it. If you take one of the eggs and put it in boiling water, the egg hooked up to the polygraph machine will go crazy.
With plants and yogurt. If you hook up a polygraph to a plant, and have a cup of "live" yogurt beside it. If the yogurt is disturbed (such as stirring up the fruit in the yogurt). This will kill the live bacteria in the yogurt and the plant would react.
Lastly, the guest said that you can't (for the most part) beat a polygraph with anything mjaor (such as if you murdered someone). Why? Because you conscience would get the best of you. The one exception is if you life was in danger. (he didn't elaborate much on what that meant)
And lastly, a link to the show
Is it true that more people vote for the winner of American Idol, than vote for the president? -Ali G.
There was a recent study where a small number of people were able to detect lies with a nearly 100% accuracy. To me, this is far more impressive than a polygraph's results.
What you are referring to is something that is called the "base rate fallacy". This mathematical fallacy occurs when you try to interpret the results of a test without taking into account the frequency of the thing being tested for in the population being sampled.
Taking the claimed 96% accuracy rate as a given, suppose that 1/10K people are terrorists. If I randomly polygraph 10K peple, I'll on average turn up 1 terrorist and 400 false positives. I can only be 1/4 of one percent sure in my result.
On the other hand, suppose I know that 50% of the people working in an office are stealing supplies, but I don't know which. If I test 100 people, I'll get 4 false positives and 48 true positives. I can be 92% positive than any person who failed their polygraph steals office supplies.
The lesson is this: evidence can only be weighed in context. There will probably never be a single test that can determine the truth on its own.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
"I am lying." or "This sentence is a lie."
It's not true or false. ...maybe it would break...
She can tell when I'm lying 100% of the time....
It's better to be the foot on the boot than the face on the pavement. ~~ tkx Kadin2048
I've taken one polygraph in my life. I was 19 and full of that sort of moral superiority that comes from the false certainty of youth. I answered all the questions truthfully, especially the one about whether I'd ever smoked pot. I hadn't and thought anyone who did was a loser. In fact, I felt strongly about the subject.
Afterward, the guy puts his arm around me and tells me I passed and that one lie that I told about the pot wouldn't be held against me. He patted me on the back and sent me on my may.
One anomalous response was interpreted as a lie. A faulty technology had convinced a total stranger that I smoked pot when I never had. The report of that session went to my new employer who didn't fire me but did make the report available to another employee who happened to be my sister. To this day, she thinks I've experimented with drugs when I haven't. After all, what's my word balanced against a neat-o cool technology with all those scribbling pens and sensors and stuff, right?
Polygraphs are bunk. People who make their living in that industry are, by my definition, liars and should be shunned.
Yes, I know I'm only one data point. But sometimes it only takes one data point to know when a technology has failed and is not trustworthy in broad application.
I took three polygraphs as part of a process to obtain a security clearance (no, I didn't get it.) I believe the effectiveness of the polygraph has little to do with the 'technology', and a lot to do with the theater surrounding the examination.
From Skepdic:
'It doesn't appease me that many defenders of the polygraph know it is junk science but defend its use because many people confess to crimes during interviews done before or after being given the test. The machine may not be able to detect lies accurately but, as Richard Nixon said, "it scares the hell out of people." The end justifies the means.'
I did not become a vegetarian for my health, I did it for the health of the chickens. --Isaac Bashevis Singer
Falls positives is what I am worried about. People being convicted because they were nervous and upset about being charged with something they didn't do.
MMO Quests are like orgasms:
You may solo them, I prefer them in a group.
Other agencies that administer lifestlye polygraph examinations, such as the CIA and NSA, do not make their polygraph failure rates public, though I suspect that they are somewhat lower than the FBI's.
In the Department of Defense (which uses a counterintelligence-scope polygraph), virtually everyone passes: the only ones who "fail" seem to be those who make what DoD terms "substantive admissions."
For information on what you might expect during your polygraph examination, and tips on how you might protect yourself against the risk of a false positive outcome, see Chapters 3 & 4 of The Lie Behind the Lie Detector (1 mb PDF).
George W. Maschke
AntiPolygraph.org
Polygraphs pick up body reaction. Sadly to few are used and humans are to complex to truly be able to tell why a person reacts.
A simple test is a pedophile image. Both a pedo and a normal person would react with an increased heart rate. The pedo because he is excited, the normal person because of revulsion.
Only when you would start to measure things like blood chemistry and brain activity would you be able to do a true polygraph.
At the moment it is like trying to tell if someone if is lying in an interview by crossing their arms (said to be a typical defensive position). It might just be they are hiding a stain they suddenly spotted, are cold, trying to stop their arms from moving because they are expressive people and been told off about it, just plain nervous about job interviews, trying to hide their beer belly, are just listening to what your saying and really thinking about it.
Polygraphs are a tool, not 100% reliable but an indication for investigators in wich direction they could be looking for more solid evidence.
Those who riducle polygraphs forget one tiny little detail. Most criminals are not smart, prepared, cool blooded and calculated offenders. Just as often as not the polygraph is a bluff wich the criminal will fail just because they know they are guilty and will be found out.
Smart people beating a police polygraph is a total lie. Smart people are never even questioned by the police.
MMO Quests are like orgasms:
You may solo them, I prefer them in a group.
Sorry, but I can't allay your fears. I failed the lifestyle polygraph three times. The first time, I was told I was lying when I said I had not committed a serious crime; we're talking rape, murder, extortion, and the like. I assure you, I have not. The first polygrapher also berated me for being vegan.
The second time, I was told that I was telling the truth about not committing a serious crime. Well, I gave exactly the same answer as I had during the first polygraph. Did I uncommitt a serious crime? Did I forget I had committed it since my first polygraph?
It seems, however, according to the polygraph at least, that I was stupid enough to experiment with drugs or to sell drugs sometime between my first and second polygraph. For, during the second polygraph, I was 'lying' when I said I had not.
During the third polygraph, where I was told I am very lucky (for it is apparently very rare for someone to be seen a second time, let alone a third; I assure you it is not rare), I was not lying about not using or selling drugs, but the serious crime problem popped up again.
As an experiment during the third polygraph, I lied when I answered one of the questions about all of the information on my form being correct. I took a trip to Canada (my first time leaving the USA) after my second polygraph, but I never amended my form to include it, because I didn't want to have to go through the hassle. The polygrapher wasn't really interested in my answer to this question, apparently.
It was an interesting experience, and gave me some good anecdotes to share with others, but it didn't help anyone figure out if I was telling the truth or not.
I did not become a vegetarian for my health, I did it for the health of the chickens. --Isaac Bashevis Singer
is in Scientology. Those individuals train for years to defeat a lie detector, even if they're not ready for it. The e-meter basically is a lie detector (it's a little hyper-sensitive on any reaction, as is shown from their "rock slam" of the needle bouncing like mad since they don't use the reduced bounce meters) that they train against for years to get to where nothing they say or do will carry a reaction (i.e. "floating").
Naturally, as was said before, you can defeat most polygraph tests with 30 minutes of training, or using the ability to answer the "wrong" question with the right answer for what they're asking you.
not exactly. 96% statistical accuracy means that if you have a population of 49 honest people and 1 spy (or H honest people and S spies for a total population of H+S) that it will pick out the S spies 96% of the time.
.00000939 or 9.39 per million
to have what you suggested, the test would have a 96% "POWER" (or a 4% beta error for n=50).
Alpha error (Type I error) = Probability(X returns false | X is actually true) => false negative
Beta error (Type II error) = Prob(X returns true | X is actually false) => false positive
The actual probability that a 96% accurate polygraph machine would do what you describe (1S + 49 => 2S that are really H) is:
(.96^47)(.04^3) =
This says that it got 47 people right (47H) and 3 wrong (2H + 1S). THAT is what a 96% accuracy means.
Do I believe the doctor's claim that the machine is that accurate? Hell no. I think the doctor that created the claim has a failed understanding of whata statistics actually mean and is giving a stat for something else entirely.
-Ab
Nothing fails quite like prayer.