Associated Press writer Mike Robinson reports on the use of polygraphs by the state of Illinois in this article reported by KARE11.com:
Polygraph tests used to help decide whether to free sexually violent offenders held at a state center in Joliet after finishing prison sentences are unscientific and even “biased against truthful people,” according to an expert’s report.
There is doubt as to whether such tests “can ever be highly accurate” because they aren’t “anchored to sound psychological theory,” says William G. Iacono, a psychology professor at the University of Minnesota.
His report was prepared for the American Civil Liberties Union of Illinois, which is suing the state, asking improved treatment and conditions at the center for violent sexual offenders.
The unit is attached to the Joliet Correctional Center but is operated by the Illinois Department of Human Services — not the Department of Corrections.
According to another recent report prepared for the ACLU, 129 people are being held there. They are called patients and are supposed to receive treatment.
Susan Locke, a spokeswoman for the human services department, said it doesn’t comment on pending lawsuits and therefore would have no comment on Iacono’s report.
State law allows authorities to hold the offenders at the center until experts deem their treatment so successful they are unlikely to commit more sexually violent crimes.
Polygraph, or lie-detector, tests play a crucial role in measuring such progress.
Iacono has served as a polygraph consultant to the congressional Office of Technology Assessment, the Central Intelligence Agency and the Defense Department, among others.
In his 15-page report he expressed skepticism on whether so-called control-question tests using polygraphs are reliable.
In such a test, the subject is asked control questions, such as: “Have you ever told a lie?”
Once his response to such questions is noted, he is asked more relevant questions, such as whether he has told authorities about all of the sexually violent crimes he has ever committed.
Responses such as sweating palms and higher blood pressure are supposed to indicate lies.
Iacono said, however, that such tests can be misleading.
He said patients are likely to attach considerable emotional weight to the relevant questions and show signs of heightened physical activity even if they are telling the truth.
“Truthful examinees are often more bothered by the emotionally charged accusations in the relevant questions than in the trivial issues raised by control questions,” he said. “The inadequacy of the control questions causes the (test) to be biased against truthful people.”
Research shows that more than 40 percent of those who tell the truth will produce symptoms that suggest they are lying, he said.
Moreover, the tests as given in Joliet could be even more suspect, Iacono said.
He said just one of the center’s employees is responsible for polygraphing all of the patients and that person does not record the sessions so that they can be reviewed by experts.
“This entire polygraph program is in the hands of a single person whose accurate administering tests is unknown and whose errors have no way of ever being detected,” he said.