Latest Study Indicates "Lie Behind the Lie Detector" Hurts Innocent, Doesn't Help Guilty

[nopolycop]

Mr. Webb:

Thank-you, sir, for your response to my question.  Unfortunately, my knowledge of polygraph is limited, and thus I could not precisely follow your explanation in order to answer my questions.  I am hoping you will do me the favor of allowing me a couple of follow-up questions, in order for me to understand better.  

Follow-up question #1)  As I understand your response, the accuracy of the polygraph was not being tested in this study, but I also know that sometimes in science, one study will produce ancilary discoveries that overshadow the original intent of the study.  With that in mind, according to Mr. Maschke's ascertation, 35% of the "innocent" test subjects were incorrectly found by the computer scored polygraph to be guilty.  Is this correct?

Follow-up question #2)  As I understand your response, while the overall number of test subjects was 40, the sub-groups actually numbered only 10 each, and each of those sub-groups, were then scored by the computer scoring system, after which the results were compared to each other.  If this is the case, (please correct me if I am wrong), isn't 10 subjects too insignificant a number to base any valid conclusions from?  It has been many years since I took my psychological statistics class in college, so my memory is fuzzy here.

Thank-you in advance for your time.

[nopolycop]

Mr. Webb.  Please allow me to thank-you for your previous time, but your input is no longer needed or requested.  I was able to obtain a copy of the aforementioned study, and it is much easier to read and understand for a layman such as myself.

What I gleaned from my reading the original study is the following:

40 subjects were given a polygraph, 20 each who were actually innocent of the faux crime of stealing some movie passes, and 20 who were actually guilty of the same faux crime.  Of the 20 "innocent" subjects, the polygraph results actually showed that 7 of those 20 were accused of being guilty.  Of the 20 subjects who were actually guilty of the faux crime, the polygraph found 16 of the 20 subjects guilty.

So, according to Mr. Hont's study, a polygraph found 7 innocent people guilty, and 4 guilty people innocent, resulting in an error rate of 27.5%.

My comparison study...

It has been said that the results of a polygraph are no better than a flip of a coin.  To determine if this hypothesis is correct, I took the last 5 minutes and flipped a quarter 40 times.  The results of my 40 flips were 22 heads and 18 tails.  I guess the polygraph is in fact more accurate than a flip of a coin, but certainly not to the accuracy quoted by many.

Any thoughts?  

[1904]

Speaking from my limited 20yrs approx experience as a p/g & cvsa examiner, I think that lab studies
conducted to gauge the effect of CM's are a total waste of time and are no more accurate than parlour games. A bunch of students trying to win movie tickets....?....Pulleeese.

A meaningful research project in this regard should utilise real subjects - baddies. Convicts.
Psychologists to coach the cons to lie about their already confessed crimes and other minor (non confessed) crimes; A participating examiner to teach CM's to the con; Another examiner who has no background knowledge of the con and whom is not privy to the CM's taught / to be implemented; And a couple of unbiased experts to oversee and control the entire experiment to ensure compliance with
guidelines.

Now that would be meaningful.

[nopolycop]

1904:

Your suggestion seems pretty valid to  me.  But, before countermeasures are studied in an unbiased manner, perhaps a study, (or a series of studies) actually attempting to scientifically measure the ability of the the polygraph to actually detect deception would be in order.

I find it amusing that the examiners who have now re-registered under their real names after being outed refuse to partake in my discussion regarding Hont's study showing the polygraph to be less than 75% accurate.  Perhaps I am not worthy of such discussion, but failure to logically counter this claim (that the study purports a poor performance regarding accuracy of the polygraph) indicates that the claim is valid.  One can tell who is reading the forums by looking at the bottom of forum home page, and I have seen several of the names as active on the forum.  In fact, as I write this, myself, 1904 and EJohnson are on line.  

[1904]

1904:

Your suggestion seems pretty valid to  me.  But, before countermeasures are studied in an unbiased manner, perhaps a study, (or a series of studies) actually attempting to scientifically measure the ability of the the polygraph to actually detect deception would be in order.   

Friend,

That is the holy grail. For every pro-study, there is an anti-study - and vice-versa, ad infinitum.
It's a case of my scientist can beat your scientist.
But, I think that our scientists are winning the tug-of-war, slowly but surely.

The fact is that there are some supremely intelligent people involved in polygraphy and they will put up solid arguments, some of which they will win and some of which they will lose.

The debate will never cease. I think that we should all now try to keep it civil and refrain from personal
insults, unless of course they are totally necessary.







Regards,

[George W. Maschke]

1904,

There's no raging debate among scientists about polygraphic lie detection. There is broad consensus that it is has no scientific basis. As Gino has noted before, the only remaining debate pits those who understand that polygraphy is junk science against those who don't (yet) and those with a vested interest in the perpetuation of polygraphy. See Chapter 1 of The Lie Behind the Lie Detector and the sources cited there for a thorough debunking of polygraphy.

[EJohnson]

1904,

There's no raging debate among scientists about polygraphic lie detection. There is broad consensus that it is has no scientific basis. As Gino has noted before, the only remaining debate pits those who understand that polygraphy is junk science against those who don't (yet) and those with a vested interest in the perpetuation of polygraphy. See Chapter 1 of The Lie Behind the Lie Detector and the sources cited there for a thorough debunking of polygraphy.

Wrong!----Give that man a gym membership folks, and thank him for playing! George, of course there is raging debate. The anti-crowd only accept hard science, the real scientific community isn't so preoccupied with the differences and distinctions between hard and soft science---the classic example being behavioral psychology vs. Neuro-psychology. Plain and simple---the polygraph test is a unique hybrid of the two, and despite your venom and Gino's spit, polygraph is scientificaly valid and is effective at detecting deception at far better than chance levels (NAS STUDY.) You folks clearly don't like the method and it's mechanisms-----fine. You can't burn steal though.

[nopolycop]

1904,


Wrong!----Give that man a gym membership folks, and thank him for playing! George, of course there is raging debate. The anti-crowd only accept hard science, the real scientific community isn't so preoccupied with the differences and distinctions between hard and soft science---the classic example being behavioral psychology vs. Neuro-psychology. Plain and simple---the polygraph test is a unique hybrid of the two, and despite your venom and Gino's spit, polygraph is scientificaly valid and is effective at detecting deception at far better than chance levels (NAS STUDY.) You folks clearly don't like the method and it's mechanisms-----fine. You can't burn steal though.

Mr. Johnson:

Are you going to address my questions/claims about the accuracy of the polygraph as it was revealed in Mr. Hont's study, or just argue with George?

[raymond.nelson]

The debate will never cease. I think that we should all now try to keep it civil and refrain from personal
insults, unless of course they are totally necessary.







Regards,

Which, by implication, suggests that sometimes they are... totally necessary???

I'd like to point out that Ludovico, and others, seem to have been banned for insulting the sensibilities of other users with references such as bub, pal, boss, and chief. While others were hurling sexualized and vulgar insults of "whore" and "dick."


r

[George W. Maschke]

Mr. Johnson,

The National Academy of Sciences' Committee to Review the Scientific Evidence on the Polygraph did not endorse the validity of polygraphy. On the contrary, the panel reached a very different conclusion (at pp. 212-13 of its report, emphasis in the original):

Polygraph Accuracy Almost a century of research in scientific psychology and physiology provides little basis for the expectation that a polygraph test could have extremely high accuracy. The physiological responses measured by the polygraph are not uniquely related to deception. That is, the responses measured by the polygraph do not all reflect a single underlying process: a variety of psychological and physiological processes, including some that can be consciously controlled, can affect polygraph measures and test results. Moreover, most polygraph testing procedures allow for uncontrolled variation in test administration (e.g., creation of the emotional climate, selecting questions) that can be expected to result in variations in accuracy and that limit the level of accuracy that can be consistently achieved.

Theoretical Basis The theoretical rationale for the polygraph is quite weak, especially in terms of differential fear, arousal, or other emotional states that are triggered in response to relevant or comparison questions. We have not found any serious effort at construct validation of polygraph testing.

Research Progress Research on the polygraph has not progressed over time in the manner of a typical scientific field. It has not accumulated knowledge or strengthened its scientific underpinnings in any significant manner. Polygraph research has proceeded in relative isolation from related fields of basic science and has benefited little from conceptual, theoretical, and technological advances in those fields that are relevant to the psychophysiological detection of deception.

Future Potential The inherent ambiguity of the physiological measures used in the polygraph suggest that further investments in improving polygraph technique and interpretation will bring only modest improvements in accuracy.

That's about  as strong a condemnation as is possible in a consensus scientific report. Speaking more plainly, the Commitee's chairman, Professor Stephen Feinberg stated, "Polygraph testing has been the gold standard, but it's obviously fool's gold."

I note that Charles Honts, a co-author of the article that is the topic of this discussion thread, was discredited by a federal judge after he attempted to characterize the NAS report as endorsing the validity of polygraphy.

[EJohnson]

1904,


Wrong!----Give that man a gym membership folks, and thank him for playing! George, of course there is raging debate. The anti-crowd only accept hard science, the real scientific community isn't so preoccupied with the differences and distinctions between hard and soft science---the classic example being behavioral psychology vs. Neuro-psychology. Plain and simple---the polygraph test is a unique hybrid of the two, and despite your venom and Gino's spit, polygraph is scientificaly valid and is effective at detecting deception at far better than chance levels (NAS STUDY.) You folks clearly don't like the method and it's mechanisms-----fine. You can't burn steal though.

Mr. Johnson:

Are you going to address my questions/claims about the accuracy of the polygraph as it was revealed in Mr. Hont's study, or just argue with George?

Mr. Honts study was predicated on earlier accuracy studies---not an exclusive accuracy study in and of itself. The study demonstrated that countermeasures do have grave pollutive affect on many aspects of the test, just not the aspects that were claimed by antipolygraph.org. What's there to debate? Your points are points of polygraph accuracy, not TLBTLD efficacy in creating intentional false negatives or guranteeing true negatives. Nopoly4, your point is off topic, and very "trolllike". Who are you, where do you live? Could we get a full scope ID on nopoly4me?

[nopolycop]

1904,


Mr. Johnson:

Are you going to address my questions/claims about the accuracy of the polygraph as it was revealed in Mr. Hont's study, or just argue with George?

Mr. Honts study was predicated on earlier accuracy studies---not an exclusive accuracy study in and of itself. The study demonstrated that countermeasures do have grave pollutive affect on many aspects of the test, just not the aspects that were claimed by antipolygraph.org. What's there to debate? Your points are points of polygraph accuracy, not TLBTLD efficacy in creating intentional false negatives or guranteeing true negatives. Nopoly4, your point is off topic, and very "trolllike". Who are you, where do you live? Could we get a full scope ID on nopoly4me?

Addressing the last two lines, when I first logged on to this site, I read the lead paragraph about using an alias, which I took to be good advise.  As far as any personal information, forget it.  Any personal information about me opens me up to personal attacks, which I am not interested in fostering, nor participating in.  I think is fairly disingenious of you to suggest that because I use an alias, that fact somehow puts me into the "troll" catagory, given your past history.  

Moving on...

As I stated in a previous post, scientific studies can expose results which are ancilary to the original purpose of the study, but are still significant in their own right.  Given the study in question, it appears that this is the case.  I notice you do not challenge my assertion that the study indicates the accuracy of the polygraph (in this test anyway) is no better than 73%.   I will take that lack of challenge as agreement to this assertion.

Given that fact then, with an error rate of over 25%, how can any honest reviewer conclude that the study proves anything regarding the effectiveness of countermeasures, when the polygraph itself could not detect blatant deception?  Add in the variable of self-reporting, ("uh, yah, I used some of those things I read about in the lie book, can I have my movie passes now?") while it sounds pretty impressive, it really is just a good example of the type of junk-science that seems to be passed off for true research in this field.

[1904]

Which, by implication, suggests that sometimes they are... totally necessary???

Totally tongue in cheek sir.

[raymond.nelson]

George W Maschke:

There's no raging debate among scientists about polygraphic lie detection. There is broad consensus that it is has no scientific basis.

I would respectfully submit that you have been in violation of your own posting policies for some time when you make this assertion.

There is no such broad consensus. The presence of a 400 page review of the science of polygraph speaks to the complexity of the scientific basis for the test. There is in fact a scientific basis for polygraph test, in terms of a number of important psychological theories and constructs, known physiology, and the basic principles of inferential and bayesian predictions in the field of testing, diagnostics, signal detection, and decision theory.

Whether you like that fact, are satisfied with the present answers or even disagree that we have a fully developed or a mature understanding of the scientific basis for polygraph is another matter. There are a number of scientific theories underlying the polygraph test.

I believe you are deliberately providing inaccurate information to your readers here, and that appears to be a violation of the posting policy.

AntiPolygraph.org prides itself on its commitment to free speech.  All points of view are welcome here, including those of polygraph supporters. However, we ask that in posting, all involved remain civil. You agree, through your use of this message board, that you will not post any material which is false, defamatory, inaccurate, abusive, vulgar, hateful, harassing, obscene, profane, sexually oriented, or threatening. Any such posts may be removed to the Discarded Posts forum, and those making such posts may be banned. Such posts by repeat offenders may be deleted. Spam, flooding, advertisements, chain letters, pyramid schemes, and solicitations are also inappropriate. Such posts will be promptly deleted and those making them banned.

Would you please correct the errors of your previous postings, so that you are no longer in violation of your posting policies.

Thank you.


r

[Sergeant1107]

Wrong!----Give that man a gym membership folks, and thank him for playing! George, of course there is raging debate. The anti-crowd only accept hard science, the real scientific community isn't so preoccupied with the differences and distinctions between hard and soft science---the classic example being behavioral psychology vs. Neuro-psychology. Plain and simple---the polygraph test is a unique hybrid of the two, and despite your venom and Gino's spit, polygraph is scientificaly valid and is effective at detecting deception at far better than chance levels (NAS STUDY.) You folks clearly don't like the method and it's mechanisms-----fine. You can't burn steal though.

The NAS study used the term "better than chance" to describe specific incident testing, and specified that it was only pertinent when the subject population was untrained in countermeasures.  

How can you tell is someone is untrained in countermeasures?  If they show no signs of using them?  Wouldn't a person skilled in countermeasures also show no signs of using them?

From page 214 of the NAS report:

Notwithstanding the quality of the empirical research and the limited ability to generalize to real-world settings, we conclude that in populations of examinees such as those represented in the polygraph research literature, untrained in countermeasures, specific-incident polygraph tests for event-specific investigations can discriminate lying from truth telling at rates well above chance, though well below perfection.

Accuracy may be highly variable across situations. The evidence does not allow any precise quantitative estimate of polygraph accuracy or provide confidence that accuracy is stable across personality types, sociodemographic groups, psychological and medical conditions, examiner and examinee expectancies, or ways of administering the test and selecting questions. In particular, the evidence does not provide confidence that polygraph accuracy is robust against potential countermeasures. There is essentially no evidence on the incremental validity of polygraph testing, that is, its ability to add predictive value to that which can be achieved by other methods.

It's amusing that you referenced the NAS report when we keep hearing from polygraph examiners (including the APA's web site, which devotes an entire page to refuting the NAS report) that is was flawed and should be disregarded.  I can understand why polygraph examiners are desperate to discredit the NAS report - it is a damning condemnation of their pseudoscientific profession.  The conclusions in the report are clear - the polygraph presents a danger to national security objectives.  

I've read the report and it is compelling, even to a layman.  It is logical and and the conclusions drawn from the research cited are quite understandable.  Hearing from polygraph examiners that the report should be ignored is no more credible than hearing from Big Tobacco that the health warnings regarding cigarettes should be ignored.