Chicago Tribune staff reporter Jason George reports:
A polygraph showdown
`Detector of Deception’ vs. The Skeptical ProfessorBy Jason George
Tribune staff reporter
March 15, 2007Fred Hunter’s Hinsdale office sits far from the concrete courthouses where you imagine most polygraphers ply their trade. A Ferrari dealership is stationed around the corner, and a McDonalds that could be mistaken for Williams-Sonoma gleams from across the street.
Yet walk inside Hunter’s office, and you will come upon the same iconic machine made famous in film scenes of sweaty interrogations and double-agent double-crosses.
The polygraph — literally “many writings” — reflects the age-old belief that telltale signs in the body betray a liar. And despite what people commonly call it, the polygraph is no lie detector — 1920s newspapermen, not polygraph examiners, first affixed that title.
In truth, the machine merely creates charts from physiological data it collects in four typical ways: rubber tubes across the chest and across the stomach both measure respiratory activity; metal plates on the fingers record sweating ; and a blood-pressure cuff monitors cardiovascular activity. It is up to the person operating the machine — the “detector of deception,” as the 103 licensed Illinois polygraph examiners are called — to interpret the charts and declare signs of deceit.
To skeptics, that interpretation is nothing more than educated, inaccurate guesswork. But to Hunter, the technology does what it’s supposed to. He has been reading polygraph charts for 42 years and is past president of the Illinois Polygraph Society. And he estimates that he has administered 30,000 polygraph exams during his career, on everyone from bank employees to sex offenders.
“Whoever punches my dance card,” he says. “I’ve done everything but looking for spies.”
So as a believer in the polygraph, Hunter was delighted one recent morning at the chance to hook up Ken Alder, a skeptic and author of the new book “The Lie Detectors, The History of an American Obsession” (Free Press, 352 pages, $27).
“This is like coming over to the dark side for you, isn’t it?” Hunter chuckled as he tightened the blood-pressure cuff on Alder’s arm.In his book released last week, Alder, a history and humanities professor at Northwestern University, questions why Americans cling to the belief this 90-year-old technology can see into our souls and reliably separate right from wrong.
“Why, despite the avalanche of scientific denunciations, does the United States — and only the United States — continue to make significant use of the lie detector?” he asks in the book. The answer, he concludes, has more to do with national character than scientific proof.
At the end of the 19th Century, European inventors tinkered with machines to try to read human behavior in a scientific manner. And in 1913, the modern lie detector was born when a Harvard student developed a way to monitor classmates’ blood pressure for measurable differences between when they told the truth and when they didn’t. A decade later, after police and a professor on the West Coast further developed the machine, the polygraph’s popularity exploded.
The climax of innumerable dramas hinged on the belief that master spies, straying spouses and untrustworthy employees all could be caught by a tiny tic, a change in blood pressure or other signs imperceptible to the casual eye but legible to the dispassionate machine. Offering to take a lie detector test became the ultimate protestation of innocence.
O.J. Simpson, former U.S. Rep. Gary Condit of California and the parents of JonBenet Ramsey represent just a handful in recent years who have responded to criminal allegations by volunteering to take a polygraph.
Some people seem to ignore the fact that, almost from the beginning, the mainstream scientific community has questioned the validity of polygraph results. As early as the 1920s, certain U.S. courts refused to admit polygraph tests as evidence — a practice still followed by many state criminal courts, including Illinois, though most federal judges can accept polygraph results if they choose.`Far from satisfactory’
As recently as 2003, the National Academy of Sciences declared the evidence supporting polygraph tests “scanty and scientifically weak.”
“Our conclusions are necessarily based on the far from satisfactory body of evidence on polygraph accuracy, as well as basic knowledge about the physiological responses the polygraph measures,” the NAS concluded.
The American Polygraph Association disagrees, maintaining the academy didn’t look at enough data. However, “a lack of resources over the past decades has hampered more meaningful research,” the association concedes.
Hunter has heard the criticism ever since he got in the business in 1965, and he resents the claims that he and other examiners do nothing more than employ a placebo gadget to bully people into confessing crimes.
“I know what I’ve done in my business,” he says. “I know I’ve done good work. And I know I’ve done errors, but I think I’ve learned from those.”
Alder argues that the lie detector has managed to maintain its grip on popular culture not because it’s foolproof, but because of Americans’ desire for technology to solve our problems and a deep belief that justice can be blind.
“To deceive is human,” he says, but “only in America has the campaign to expose lies taken a techno-scientific turn.
“We believe in the lie detector because — no matter what respectable science says — we are tempted.”
“Who wouldn’t be tempted by a device that let you read the thoughts of your fellow citizens?” Alder asks in his book’s preface. “And who wouldn’t hesitate to be hooked up to such a device?”
Alder did his own bit of hesitating before recently agreeing to visit Hunter’s office for some first hand research.
“I’m a bit nervous,” he said with a weak grin. “But I’m excited.”
Illinois regulations do not allow polygraph examiners to give public demonstrations of complete tests — a decades-old rule instituted to discourage advertising stunts. So this day, Hunter administers a “stim test,” which involves Alder deliberately lying about something both men know to be untrue. Then Hunter examines the paper chart to pinpoint the places Alder’s physical responses indicate he wasn’t telling the truth.
He starts by asking Alder to choose a number that, during the test, he will deny selecting.“Pick a number between 1 and 10,” Hunter says.
“Pi,” replies Alder.
Hunter rolls his eyes: “A whole number.”
“3.5,” Alder taunts.
“Oh, OK,” Hunter concedes, losing Round 1 of the battle of the wills. “Just pick a letter.”
Alder selects “E.” And as the four needles dance up and down, scribbling lines across Alder’s scrolling chart, Hunter asks Alder if various letters are his selection.
“No,” Alder replies each time.
Then Hunter reaches the pre-selected `lie letter.’
“Did you choose the letter E?” Hunter asks.
Alder denies it, both calmly and emphatically.
This naming and denying of letters continues for minutes more, until Hunter switches off the machine, looks down over his glasses at the chart produced and grins from ear to ear.
“I should have bet you money,” he exclaims. “You were too easy!”
The men then lean in together to examine the results, but they come up with quite different assessments of what it reports. Hunter sees clear peaks in the scribbles where Alder “deceived” him by saying `E’ was not his letter. Alder points to high marks near other, unrelated questions.
`Not perfection’
It’s a stalemate of sorts. But after nearly two hours together, both men hedge their positions in a gentlemanly fashion.
“Polygraph is not perfection, but used within parameters, it’s a great tool to use,” Hunter says. “You describe it well in your work,” he tells Alder. “It’s the search for the definitive way to catch the boogeyman.”
The professor thanks him for the compliment, hands him a signed copy of his new book and returns the praise, saying that experts such as Hunter obviously have more success with the machine. “That’s where the difference comes in between an experienced examiner and one who’s not,” Alder says, shaking Hunter’s hand.
The handshake stretches across the same gulf that opened when polygraph was invented: academic versus examiner, science versus experience.
At this moment, each agrees the other’s argument has merit.
It’s probably as close as they’ll ever get.
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