City Council Polygraph Tests Leave Questions Unanswered
Mayor Keith Holliday and seven other Greensboro City Council members lined up last week for polygraph tests designed to answer one question: Did they leak the Risk Management Associates report about police practices to the News & Record?
But one fundamental question is unlikely to be answered by the results of the tests. Can polygraphs determine who is lying and who is telling the truth?
Mayor Holliday announced May 5 that all eight council members passed the tests. One city council member, District 1 representative Dianne Bellamy-Small, declined to take the test on the grounds that the action was divisive.
Military and most civilian courts have ruled polygraph results to be inadmissible as evidence. However, the procedure is commonly used to screen applicants for law-enforcement and intelligence jobs.
‘“What the Greensboro City Council has done looks pretty foolish to me,’” said George Maschke, founder of AntiPolygraph.org. ‘“The people of Greensboro shouldn’t put any weight on the outcome of these tests. It is not going to shed any new light on the situation.’”
Maschke e-mailed the mayor and all the members of the city council after they voted to undergo polygraph examination urging them not to go through with the procedure. He and the co-founder of AntiPolygraph.org both failed pre-employment polygraphs for the FBI.
The most common polygraph exam is called a Control Question Test. The relevant questions pertain directly to the crime or incident at issue while control questions ask about a history of dishonest behavior.
In the Greensboro City Council’s case, a relevant question could be, ‘“Did you leak the report to the News & Record?’”
The control set might include questions like, ‘“Have you ever lied to get out of trouble?’”
The machine measures physiological responses to such questions, including heart rate, respiration, perspiration and blood pressure. Practitioners theorize that innocent subjects will lie on control questions and answer the relevant questions truthfully. Innocent subjects will demonstrate stress reactions consistent with lying on control questions but not relevant ones, proponents argue.
‘“The data shows that they are quite reliable in some settings and not in others,’” said Charles Honts, a psychology professor and polygraph proponent. ‘“It works well with very specific issues like crimes.’”
In specific situations, the polygraph has demonstrated accuracy rates between 80 and 90 percent. But Honts said any given test has a one in 10 chance of being wrong. Honts advocates making polygraphs admissible in court because their accuracy rates are higher than many other psychological evaluations commonly used as evidence.
Opponents of polygraph examinations question the results of studies that have shown high accuracy rates. The National Academy of Science found that polygraph testing lacks sufficient validity to be used as pre-employment screening in a 2003 paper.
In a hypothetical situation where the test was used, with an expected 80 percent accuracy, to find 10 spies out of 10,000 employees, the test did correctly identify eight of the spies. However, it also returned false positives for 1,598 employees. Two spies returned false negatives.
Drew Richardson, a former employee of the FBI’s Laboratory Division and Greensboro native, said the tests can be beaten with both mental and physical countermeasures.
‘“The way it’s typically done is to find ways to produce higher responses to control questions,’” Richardson said.
Subjects can imagine a difficult math problem or bite the side of their mouth to produce the requisite physical reactions, he said. The questions are often reviewed in advance for examinees, making it easier for them to differentiate between control and relevant.
Honts disputed the effectiveness of countermeasures, saying that subjects must be trained by experts to beat a polygraph. About half the subjects in a laboratory setting can be taught countermeasures, but reading about it isn’t enough, he said.
Another one of Richardson’s concerns is that the test actually penalizes truthfulness. If a subject tells the truth on a control question designed to make them lie, they might register a false positive. It is a concern shared by Maschke.
‘“The problem about it is, suppose you make admissions,’” Maschke said. ‘“The more admissions a person makes and the more truthful they are, the more likely they are to fail.’”
The National Academy of Science concluded that polygraphs detect deception in incident-specific scenarios well above chance but well below perfection. The city council members spent $5,000 of their travel budget on the exams.
Maschke said the city council in Irondale, Ala. used polygraphs to determine the source of a leak in 2003, but he heard the tests did not work. On the federal level, the CIA recently fired employee Mary McCarthy for allegedly leaking information about secret prisons in Eastern Europe to the Washington Post after she failed a polygraph.
‘“The biggest misconception is that a polygraph can detect lies,’” Maschke said. ‘“But nothing about what it measures has any clear connection to deception.’”
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