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Challenging The 'Unbeatable' Polygraph

Posted by timothy on from the scuffle-worth-scuffling dept.

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."

22 of 101 comments (clear)

  1. 96% accurate? by hankwang · · Score: 3, Informative
    From the first article:

    "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.

    --
    Avantslash: low-bandwidth mobile slashdot.
    1. Re:96% accurate? by George+Maschke · · Score: 5, Interesting
      Right, even a test that is accurate 96% of the time is going to produce many more false positives than true positives when the base rate is low.

      But while Dr. Rovner asserts that he is "confident that polygraph tests have a 96% accuracy rate when done properly," the scientific community has no such confidence in polygraphy. The National Academy of Sciences recently published a report titled The Polygraph and Lie Detection that concluded that the theoretical basis for polygraphy is quite weak and that that almost a century of research provides little basis for the expectation that the polygraph could have an extremely high rate of accuracy.

      --

      George W. Maschke
      AntiPolygraph.org

  2. Re:So... by lobsterGun · · Score: 4, Insightful

    While it is true that you cannot be convicted on the basis of a polygraph, would you want the news that you had failed a polygraph leaked to the press?

    Even if you aren't acused of a crime, consider that you can still lose your job because of a failed polygraph.

    Polygraphs are bad science; They should not be used as the basis for making decisions.

  3. remorse by Anonymous Coward · · Score: 3, Interesting

    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).

    1. Re:remorse by Anonymous Coward · · Score: 3, Informative

      That's not totally accurate.

      A polygraph works based on relative stress. Usually it goes as follows:

      First they ask some "control" questions. These are questions they already know the answers to. From that they determine your baseline responses. Then they start asking the real questions. They will usually introduce more control questions during this process so they can make sure the baseline is still working (you won't know which are the control questions during this phase).

      Do beat the machine all you have to do is fuck up the baseline. There are different ways of doing this. If you can cause physical pain to yourself that will stress your system. With a little practice many people can learn to control the stress reaction without any physical stimulus needed. By manipulating your stress at appropriate times you can distort the baseline so the polygraph interpreter can't make any solid decisions.

      And of course there are people who can just completely eliminate the stress response in their system. Those are often the people who can beat the machine without any training at all.

    2. Re:remorse by Anonymous Coward · · Score: 3, Informative

      Most polygraphs work on the idea of remorseful feelings the subject
      will have if they report a lie in response to a question.

      Sort of. This is how they work:

      There are null questions, 'control' questions, and pertinant questions which are asked by a tester who also attempts to spook/convince the victim that their 'high tech' equipment actually gives them the ability to tell if someone is lying. No equipment can tell if you are lying short of a PET scan which they can't afford to give you. Even a PET scan may not be able to distinguish from someone making up a story from scratch and someone making up details to fill in gaps in their memory. Making things up to fill in gaps in memory is something we all do.

      The tester tells the victim that the null questions are actually 'control' questions. In fact they are merely a ruse. They will ask questions like: what is your name, or what is your date of birth, but the answers and the polygraph data for those questions is discarded.

      The real control questions, are questions the tester assumes that the victim will lie about. They want to see what the polygraph data looks like when you do lie. They might ask: "Have you ever told a lie?" Everyone has told a lie. If the victim lies and says: "No, I've never told a lie." then the tester gets his data. If the victim is truthful, and admits to having told a lie, then the tester follows up with something like: "Yes, I know everyone has told a lie about SOMETHING at one time or another, but what I'm interested in is, have you ever told a lie about something important? The tester assumes that the victim has told a lie about something important. If the victim denies lying about something important, then the tester get's their control data, if the victim admits lying about something important, then the tester ups the ante, saying something like: "Yeah, lying is neccessary sometimes, but have you ever told a lie that hurt someone else, or got them in trouble?"

      The ante is upped until the the victim denies something. Testers like to pressure victims to lie on the control questions by asking control questions that seem pertinant to the issue at hand. For a job interview, they might ask about stealing from work. Even someone who never filched anything can be coaxed into lying about the five extra minutes they 'stole' on coffee break by a clever questioner.

      Then there are the pertinant questions. These are the questions that the tester is trying to determing whether you are lying or not about.

      The testers ignore they null questions - they are only part of the ruse. They expect to see the needle move in response to the provocative 'control' questions, and the needle not to move in response to the pertinant questions. This is the ideal "He's telling the truth" result. If the needle moves in response to the controls, and the pertanent questions, then the result is marked as "He's lying."

      The third possibility is that the needle never moves for control questions, or for the pertanent questions. If the victim admits to every control question the tester asks, they will have eventually wound up admitting to having sex with their neighbors dog while a busload of fourth graders watched, or some other outrage. If they did not admit to any of the control questions, and the needle didn't move, then the test is inconclusive. They could be a saint, or more likely they have no concience and can lie without making the needle move. Saints and Psychotics are filtered out of the Job Candidate pool in favor of imperfect, morally conflicted people who make mistakes and lie about it, but have at least not lied about any of the 'pertenant questions'. It pays to be what the testers know how to test. As for sainthood, no good deed goes unpunished.

      It's possible to get the needle to move by biting your cheek, clenching your anus, stepping on a tack in your shoe, or

  4. Re:So... by George+Maschke · · Score: 5, Informative

    And the claim that "almost no human being can beat a polygraph test" is flatly contradicted by the research to which I referred in the linked public challenge, wherein some 50% of polygraph subjects were able to fool the lie detector after receiving a maximum of 30 minutes of instruction...

    --

    George W. Maschke
    AntiPolygraph.org

  5. Polygraphs and plants. by ForestGrump · · Score: 3, Funny

    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.
    1. Re:Polygraphs and plants. by ForestGrump · · Score: 3, Informative

      oh look, antipolygraph.org has a thread on that show.
      http://antipolygraph.org/cgi-bin/forums/YaBB.pl?bo ard=off;action=display;num=1096866906

      --
      Is it true that more people vote for the winner of American Idol, than vote for the president? -Ali G.
  6. Don't forget human polygraphs by PIPBoy3000 · · Score: 4, Informative

    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.

  7. Base Rate Fallacy by hey! · · Score: 4, Insightful

    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.
  8. How about paradoxes? by Free_Trial_Thinking · · Score: 3, Funny
    I always wondered how a lie detector would respond to the statement:

    "I am lying." or "This sentence is a lie."

    It's not true or false. ...maybe it would break...

  9. My wife is better... by hummassa · · Score: 3, Funny

    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
  10. Re:So... by Evil+Schmoo · · Score: 3, Interesting

    True, polygraphs are inadmissable as evidence in a court of law. But that's not the main point.

    As anyone who works for a defense contractor or secure government facility can tell you, polys are the ONLY way you can get to levels of clearance above Top Secret (TS). In fact, there's TS, and there's TS-Poly above that, and then there's all the ones we can't tell you about above them.

    The fact is, people beat polys and get into extremely high levels of clearance. I personally know people who have (mostly on the drug use questions). Now, these folks are my friends, and generally good people, so I don't really have a problem with them per se -- but claiming that polys are indestructible perpetuates the mindset of the higherups that polys don't lie. I'm not saying that the GAO and DOD don't perform good background checks -- they do -- but using polys as a check of last resort leaves a fairly large hole in our nation's security net.

    Would you really want a bright young programmer to get a job in No Such Agency or DIA while having claimed his father was from Kuwait instead of Yemen, all on the strength of having beaten a polygraph?

  11. Polygraphs are bunk by BenEnglishAtHome · · Score: 5, Informative

    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.

  12. Re:So... by George+Maschke · · Score: 4, Informative

    One of the spies I pointed out to Dr. Rovner is Ana Belen Montes, who got a job with DIA at a time when she was already a Cuban agent. She passed her polygraph. The one that's supposed to tell whether or not you're a spy...

    --

    George W. Maschke
    AntiPolygraph.org

  13. The Effectiveness of the Polygraph by Jason+Ford · · Score: 5, Insightful

    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
  14. You fail by SmallFurryCreature · · Score: 4, Insightful
    What you show is that people can defeat the polygraph if they are lying. What is far more important is if the polygraph says people lie when they are telling the truth.

    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.

    1. Re:You fail by idlethought · · Score: 4, Insightful

      Think about it a step further along..

      Suspect A lies under polygraph implicating Suspect B - polygraph indicates he's telling the truth.

      Suspect B is interviewed, shown 'proof' that he committed the crime, offered a deal..

      False negatives can be just as dangerous if they are believed..

  15. Re:false positives by George+Maschke · · Score: 4, Informative
    False positive rates(along with overall positive rates) in pre-employment screening situations will vary depending on the agency. The FBI, for example, has an overall polygraph failure rate of about 50%. There is no way of knowing for sure what percentage of those are false positives, but it seems likely that many are. Before 9/11, the FBI's overall pre-employment polygraph failure rate was only about 20%. Did a flood of liars suddenly start applying for the FBI? I don't think so...

    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

  16. Re:false positives by Jason+Ford · · Score: 5, Interesting

    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
  17. The largest bank of proof by Kronovohr · · Score: 3, Insightful

    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.