Friday, December 29, 2006

An FBI Expert Testified That Lie Detectors Are Worthless for Security Screening

Now let's turn our attention to the last member of our trifecta of defective tests — the polygraph,
more commonly referred to as the lie detector. Invented by the same person who created Wonder
Woman and her golden lasso that makes you tell the truth (I'm not kidding), the polygraph is said
to detect deception based on subtle bodily signals, such as pulse rate and sweatiness. Its
proponents like to claim that it has a success rate of 90 percent or more. This is pure hogwash.
While the evidence against lie detectors is way too voluminous to get into here, it will be very
instructive to look at a statement from Dr. Drew Richardson. Richardson is a scientist who was
an FBI agent for 25 years; in the late 1980s and early 1990s, he dealt with polygraphs.
In fall 1997, a Senate Judiciary subcommittee held hearings regarding the FBI Crime Lab.
Richardson gave scorching testimony about polygraphs. Referring specifically to the practice of
using lie detectors to question people in sensitive positions, he said under oath:
It is completely without any theoretical foundation and has absolutely no validity. Although
there is disagreement amongst scientists about the use of polygraph testing in criminal
matters, there is almost universal agreement that polygraph screening is completely invalid
and should be stopped. As one of my colleagues frequently says, the diagnostic value of this
type of testing is no more than that of astrology or tea-leaf reading.
If this test had any validity (which it does not), both my own experience, and published
scientific research has proven, that anyone can be taught to beat this type of polygraph
exam in a few minutes.
Because of the nature of this type of examination, it would normally be expected to produce
large numbers of false positive results (falsely accusing an examinee of lying about some
issue). As a result of the great consequences of doing this with large numbers of law
enforcement and intelligence community officers, the test has now been manipulated to
reduce false positive results, but consequently has no power to detect deception in
espionage and other national security matters. Thus, I believe that there is virtually no
probability of catching a spy with the use of polygraph screening techniques. I think a
careful exam-ination of the Aldrich Ames case will reveal that any shortcomings in the use
of the polygraph were not simply errors on the part of the polygraph examiners involved,
and would not have been eliminated if FBI instead of CIA polygraphers had conducted
these examinations. Instead I believe this is largely a reflection of the complete lack of
validity of this methodology. To the extent that we place any confidence in the results of
polygraph screening, and as a consequence shortchange traditional security vetting
techniques, I think our national security is severely jeopardized.
After he ripped polygraphs a new one, the FBI silenced Richardson, refusing to let him speak
publicly about the subject again.

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