Many people have seen on TV in a cop show the ubiquitous use of the polygraph (a/k/a “lie detector”) Most people may well believe in the efficacy and accuracy of the polygraph with respect to “lie detection.” Nothing could be further from the truth, and the examiners and other “experts” know it.
I spent 38 years in the practice of law in a rural area. For the first 13 years or so I practiced the defense of the criminally accused. Early in my career I allowed two of my clients to be examined on polygraph at the Va. State Police Division Headquarters. (I will never do such a thing again.)
The polygraph (I refuse to label it a “lie detector” since that is a patently false label) graphically measures on a moving paper graph the fluctuations in the subject’s breathing, heart rate, and galvanic (sweat) reaction on the fingers. The assertion accepted by most is that a change in these reactions from a previously laid-down “control” image is indicative of stress caused by dishonesty. So, the person examining the alleged graphic display of stress then pronounces that such stress is most likely due to dishonesty.
The results of a polygraph exam are usually not admissible in court absent the concurrence of the accused. However, once such concurrence is obtained (rarely), the examiner (usually having no more than a high-school education) is allowed to opine, under oath, that the machine has shown “undue” or “unusual” stress, thus indicating the accused is not being truthful. This is the core of the “Big Lie.”
The sensors usually connected to the polygraph are: (1) a chest belt, which measures both the breathing rate and the size of the breaths taken; (2) a blood pressure cuff to measure heart rate; and (3) a sensor that wraps around a couple of fingers and purportedly measures the level of perspiration on the fingers, then translating that to a galvanic reaction that transmits voltage. These sensors are, in turn, connected to a device that translates the physical input from the sensors into pulsing pens scribing waves onto the moving paper graph. As the paper moves under the pens, the pulses from the sensors cause the pens to wipe back and forth across the moving graph paper, thus producing a graph showing the three inputs as “squiggles” on the paper. The examiner then looks at the pattern of the graphs and draws (or states) conclusions about the honesty of the subject. Under prevailing polygraph theory, a display of “undue” subject stress on the graph indicates a lack of subject truthfulness, according to most examiners.
I recall the polygraph exam back in the mid-1970‘s of one young girl whom I represented and who was accused of theft. She was thus examined at State Police Headquarters in Culpeper. The examiner, a State Police officer, declared that the child was being untruthful. I asked to see the graph and to have pointed out to me the point showing my client’s dishonesty. The examiner pointed to an area on the graph that, to my eyes, displayed almost NOTHING--no apparent change in the graphic waves being laid down. Despite my expressed skepticism, the examiner, however, INSISTED she was being untruthful.
So, being naïve and inexperienced in such matters, I came to believe that my client was being dishonest. The examiner was firm in his conclusion and thereby greatly influenced my own thinking. I owe my client an apology, some 40 years later! That examiner had no business at all drawing such a conclusion. I am now convinced that he willfully and deliberately and dishonestly attempted to shore up the charges against my client by drawing a conclusion that was obviously at odds with what was shown on the graph. I am ashamed that I fell for it.
Most examiners have no business opining about stress and the signs of it. Most have no college degree and therefore no advanced education enabling them to comprehend physiological manifestations of stress. And, most examiners have no business opining about the connection between purportedly observed stress changes and truthfulness. They are drawing ultimate conclusions (and being allowed to state them under oath or by and with the authority of their public position), thereby dishonestly influencing the conclusions of others and the resultant outcomes.
There is absolutely no reliable basis for a subjective, uneducated conclusion that a particular squiggle on a piece of paper is evidence of dishonesty. NO ONE is qualified to draw such absurd, fabricated conclusions! Yet both the CIA and the FBI are still permitted to use polygraph exams of employees to ferret out alleged spies and end careers. That is insane.
No one should ever submit to a polygraph exam for any reason whatsoever. No one should ever sign an employment agreement (which the courts routinely and blindly enforce) that permits the employer to condition a hiring based on the employee’s unconditional and unlimited willingness to submit to such nonsense.
It is way past time for the US Supreme Court and the Congress to outlaw any use of the polygraph for any reason whatsoever. That this issue has been ignored for so long is conclusive evidence of the intellectual corruption of those who are sworn to protect our civil liberties.
