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CEPI Students Learn the Science of Deception Detection

By 

Mütter EDU Staff

April 13, 2016

 

A few weeks ago, students in both the and the learned career development skills through a hands-on demonstration in lie detection. A student from each program volunteered to take to a crude lie detector test, administered by Youth Program Coordinator Kevin Impellizeri. Kevin asked  a series of questions, beginning with simple ones ("What is your name?") and ending with more challenging ones ("Have you ever cheated on a test?"), all the while he monitored their pulse. Kevin assures us he cannot tell whether someone is lying; merely, he was monitoring their physical response to his line of questioning. In fact, despite its , polygraphs ("lie detector machines") do not measure whether or not a person is telling the truth; rather they monitor the body's physical response to questioning (what the American Polygraph Association describes as the ""). Polygraphs are designed to measure changes in heart rate, respiration, and perspiration, and (in theory) a trained technician can measure this biological feedback to tell whether or not a subject is lying.

However, whether or not polygraphs actually "work" is a subject of considerable debate. In 2003, the National Research Council published a detailed report on polygraphs. The report, titled , put polygraph usage into question and, among other things, cited a lack of standardized practices for questioning and the existence of countermeasures designed to "beat" a polygraph as reasons to doubt their effectiveness.  In 2004, the American Psychological Association came out against polygraph examination, describing the practice as "." Polygraph results are inadmissable as evidence in court cases in the United States; however they are still utilized to monitor paroled prison inmates and to screen candidates for jobs in law enforcement. Ironically, the Philadelphia Police Department discontinued polygraph tests for new cadets in 2003, citing lack of reliability, only to paradoxically add greater integrity to the police hiring process.

So why subject our students to a lie detector test? Job training! While the chances of being subjected to a polygraph test in one's lifetime are remote, everyone at some point has to go on a job interview, and it has been well documented that how well one conducts themselves in an interview is essential. After a lesson on polygraphs, members of CEPI borrowed from the "Physiological Detection of Deception" by going over ways to behave during a job interview, including monitoring one's verbal and nonverbal cues (body language, eye contact, timing of responses, etc.). This was followed with practice interviews to help prepare the students for success.

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