Hello, colinzo-ga!
I have tried to answer your question as best as I can without your
clarification. From the way you worded the question, I am assuming I
am on the right track. I hope this works for you. I have left the
citations for the end of the paper. Total word count, without
citations, is approximately 1585. If this is for a paper, I assume you
may want to rearrange the information to your liking. I have seperated
paragraphs according to the citations, so you can arrange the format
in any way you desire.
umiat-ga
Google search strategy
+empirical +evidence of +polygraph
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The validity of the polygraph test and its use in the legal setting
is certainly a matter of dispute.
On one hand, the accuracy of the test has been likened to palm
reading, while others believe that even the most accomplished of liars
cannot fool the polygraph.
In 1993, the Supreme Court case of Daubert v. Merrill Dow
Pharmaceuticals opened the door, which had previously been closed by
Fry v.United States, to the discussion of whether polygraph tests
should be admissible in court. Polygraph “experts” on both sides of
the issue, however, remain in disagreement about whether, and how,
polygraph evidence should be used in the courts.
What, exactly, does a polygraph purport to measure? “The polygraph
simultaneously measures and records selected physiological activities
or electro-physiological activity. The device captures the minimum of
three types of psychological data, usually differential blood
pressure, heart rate, respiration rate, and skin conductance
(subcutaneous sweating). In essence, this means that the person being
examined will fear being caught lying and his body will react
reflecting that fear, which reactions are captured by the polygraph
test.”
“The polygraph does not measure deception or lying. It merely records
physiological activity, and any attempt to use it to detect deception
involves drawing an inference from the physiological activity that it
records. Therefore, the central question regarding the use of the
polygraph in `the physiological detection of deception' concerns the
theory and method underlying the way inferences are drawn from the
physiological recordings.”
The premise, then, is that “there is a specific physiological
response pattern that is associated with deceptive behaviour. One
merely needs to observe that pattern in order to determine whether the
person being measured is attempting to deceive.” (1)
Therein lies the crux of the disagreement over the polygraph.
According to some, there is no empirical evidence to support the
measure of guilt or innocence measured by the polygraph.
“It is well established that a guilty, or deceptive person can '
beat' the polygraph by adopting appropriate physical and mental
countermeasures. These countermeasures (e.g. counting from 7 backwards
to 1) raise physiological activation levels when answering the control
questions. In summary, the theoretical rationale of polygraph tests
of deception is widely acknowledged as questionable.”
“The percentage of deceptive subjects which the test correctly
classifies as deceptive ranges from approximately 73% to 100%, with a
weighted average percentage of approximately 86%. This is 36% more
than could be expected by mere random guessing.The percentage of
truthful subjects which the test correctly classifies as truthful
ranges from approximately 30% to 83%, with a weighted average
percentage of approximately 50%. This is no more than could be
expected by mere random guessing.” (2)
There is evidence that subjects can be trained to beat the polygraph.
In a study at the University of Utah, half an hour of training enabled
50 percent of the sophomores studied to fool the polygrapher. In the
1960s, under an Air Force contract, David Lykken (author of "A Tremor
in the Blood") taught volunteers to beat the lie detector by damping
their responses -- funding was cut before there were publishable
results, but Lykken remains certain the tests are beatable. He also
suspects that spies are trained to do so. (3)
A scientific survey of 421 psychologists from the Society for
Psychophysiological Research (SPR) and Fellows of the APA's Division
of General Psychology were directed to answer two questions concerning
polygraph questioning techniques to determine their opinion on the
validity of lie detector tests. The psychologists were asked to
evaluate how accurate three different poloygraph testing techniques
were in detecting deception. The evaluation revolved around three
different types of polygraph questions.
The Control Question Test (CQT), “compares the physiological
disturbance caused by relevant questions about the crime with the
disturbance caused by questions relating to possible prior misdeeds, “
and is often used to determine whether a person should be prosecuted
for criminal involvement or not.
Another technique, called the “Directed Lie Technique” (DLT),
measures the difference in physical reactions of a client when they
told to deliberately lie versus being told to tell the truth.
The third test, called the “Guilty Knowledge Test” (GKT) attempts to
determine the client’s possession of knowledge that would only be
known to the police and the perpetrator of the crime.
The two questions asked of the 421 psychologists were:
1. Would You Say that the CQT, GKT, DLT is based on scientifically
sound psychological principle or theory?
2. Would You Advocate that Courts Admit into Evidence the Outcome of
Control Question Polygraph Tests?
The opinions measured in the survey can be summed up as follows:
“Both groups felt strongly that the CQT results should not be
admitted as evidence in court. However, almost three-fourths of both
groups viewed the GKT as scientifically sound. But even though the GKT
is seen as a promising forensic tool, we would not advocate its
admissibility in the absence of additional research with real-life
criminal cases.” (4)
“Polygraphy is not a science,” according to authors George Maschke
and Gino Scalabrini. They attest that “Polygraph “testing” is an
unstandardizable procedure that is fundamentally dependent on
trickery.1 As such, it can have no scientific validity.” For this
reason, “thousands of truthful persons have been falsely accused of
deception and suffered serious adverse consequences. On the other
hand, deceptive persons can easily defeat polygraph “tests” through
countermeasures, as did convicted spy Aldrich H. Ames.”
The authors quote the testimony of the FBI’s Supervisory Special
Agent Dr. Drew C. Richardson before the United States Senate
Committee on the Judi-ciary’s Subcommittee on Administrative Oversight
and the Courts in 1977. “[Polygraph screening] 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.” (5)
The results of polygraph testing in legal cases have been deemed
reliable enough to be used in making determinations in certain
circumstances. In Nawrocki v. Township of Coolbaugh, No. 01-1196 (3d
Cir. Apr. 8, 2002), which involved a case of one teacher suspecting
another teacher of writing threatening and pornographic letters, the
school district administered a polygraph test to the suspected
teacher. The District Court agreed that the polygraph results showed
probable cause. The Appellate Court agreed. “Polygraph results were
not admitted for their truth, but to show probable cause. Although
most appellate courts have continued to exclude polygraph evidence
notwithstanding Daubert, district court did not err in admitting
polygraph findings for this limited purpose.
The case of United States vs. Lee, No. 01-4485 (3d Cir. Jan. 7,
2003) involved the prosecution of a distributor of child pornography.
The District Court allowed the release of the defendant, with the
condition that he submit to periodic polygraph exams.(6)
In a discussion of the admissibility of polygraph evidence by the
Wake Forest Law Review, several issues are discussed that would deem a
test unreliable. There may be instances when the polygraph examiner’s
credentials are suspect or inadequate.(7)
“Polygraph examiners—particularly those working in law enforcement
settings—often form impressions of a suspect that can bias their
interpretation of the test results, notes Israeli psychologist Gershon
Ben-Shakhar, a visiting professor at Brandeis University and co-author
with Toronto psychologist John Furedy of the book, 'Theories and
Applications in the Detection of Deception' (Springer Verlag, 1990).
In a study published in 1994 in the Journal of Behavioral Decision
Making, Ben-Shakhar and his colleagues found that examiners may indeed
be biased when scoring or interpreting polygraph charts, if they have
a prior impression of an examinee’s veracity. Police may tell a
polygrapher, for example, that they are certain a suspect is guilty,
and that may taint the way the polygrapher interprets the suspect’s
physiological response to a certain question, he explains.”(8)
A tested subjects emotional instability, the ingestion of drugs to
alter the emotional state before examination, or the vagueness of test
questions are certainly reasons to discredit the polygraph test. On
the other hand, the paper stresses that the courts take a strong look
at the research surrounding the validity of the polygraph technique.
The point is made that “everyday, criminal court juries listen to
evidence that is substantially less than 90% than accurate on the
average.” It has also been mentioned in court that “a great deal of
lay testimony routinely admitted is at least as unreliable and
inaccurate, and other forms of scientific evidence involve risks of
instrumental or judgemental error.” Therefore, if the research into
polygraph testing “passes muster,” there are certain instances where
admissibility should be allowed.(7)
Although many psychologists are skeptical of polygraph exams, the
debate focuses more on the questions asked than the actual technology.
“Advocates of the tests say that the questions can be designed to
provoke revealing psychophysiological reactions, such as perspiration
and increased blood pressure, when the person being tested lies.
Critics argue that those physical responses have never been proven to
be indicators of a person’s dishonesty.”(8)
There is no doubt, however, that the debate will continue. In the
words of Brandeis University psychologist Leonard Saxe, PhD,
“'Polygraph tests keep getting called on because we want to know if
‘O.J. did it,’ or if ‘Monica Lewinsky did it. But the research
findings show that, in the real world, you can’t tell who’s lying and
who isn’t.”(8)
Works cited;
1. “Polygraph Testing – Is it as Reliable and Accurate as Everyone
Thinks?” by Kerry Knowles. CCMA. (3/21/2002) at
http://www.ccma.org.za/DisplayNews2.asp?ID=1
2. “Lecture 4 – The Polygraph. Colin Tredoux. Psychology 203S.
Psychology and Law. (10/2000) at
http://web.uct.ac.za/depts/psychology/undergrad/203s_files/polygraph.pdf
3. “Passing the Polygraph,” by Susan McCarthy. Salon.com (3/2/2000) at
http://dir.salon.com/health/feature/2000/03/02/lie_detection/index.html
4. “Psychologists surveyed on Lie Detectors Say Most Are Not Valid.”
American Psychological Association Press Release. (1997) at
http://www.apa.org/releases/liedetector.html (Based on the study,
'The Validity of the Lie Detector: Two Surveys of Scientific Opinion,'
by W.G. Iacono, Ph.D., and D.T. Lykken, Ph.D.,University of Minnesota,
Twin Cities, in Journal of Applied Psychology, Vol.82, No. 3.)
5. “The Lie Behind the Lie Detector,” by George Maschke and Gino J.
Scalabrini. Published by Anti-Polygraph.org. (2000) at
http://antipolygraph.org/the_lie_behind_the_lie_detector/the_lie.html
6. Polygraphers. http://www.daubertontheweb.com/polygraphers.htm
7. “Issues Once Moot: The Other Evidentiary Objections to the
Admission of Exculpatory Polygraph Examinations,” by Edward J.
Imwinkelried and James R. McCall. Wake Forest Law Review. Vol.32, #4
(1997) at http://www.law.wfu.edu/lawreview/V32/docs/32-4-1.pdf
8. “Psychologists Debate Merit of the Polygraph,” by Scott Sleek. APA
Monitor. (6/1999) at http://www.apa.org/monitor/jun98/lie.html |
