The Truth about Lie Detectors
Can lie detectors lie?
in early July, the civilian agent only known then as “Ador” arrived at the National Bureau of Investigation (NBI) central office, brimming with confidence that his allegations of illegal activities against Sen. Panfilo “Ping” Lacson could stand the most grueling of interrogations.
As soon as he stepped into the first floor of the NBI building, reporters naturally started chasing him, even as employees gave him the runaround as to where the polygraph examiner was going to meet him. Finally landing in a room on the second floor, Ador found a metal chair where he would be wired and strapped while being asked several questions.
The sight caused his blood pressure to shoot up, something which he could not hide behind the signature cap, dark glasses, and the gray scarf that covered the lower half of his face, all of which he didn’t take off during the whole wild goose chase.
“When I saw the polygraph machine, it was like an electric chair, so it added to my tension,” he told reporters. “And the examiner kept on telling me not to move, so I just became more tense.”
He failed his first polygraph test. Was Angelo “Ador” Mawanay lying then?
Not necessarily, experts say, because tension could produce erratic polygraph charts, based on which
the examiner would understandably make inaccurate readings.
Soon used to media attention, the intimidating setting of a lie detection exam, and reportedly coached by his handlers in the military, Ador passed two succeeding polygraph exams. He was so high on the supposed vindication that he even challenged Lacson to sit on the same metal chair to prove who between them was lying.
No, Lacson said, he would not dignify the accusations by subjecting himself to a lie detection test.
The “polygraph madness in Manila” recently caught the attention of Antipolygraph.org, a movement in the United States that has been working for the abolition of polygraph exams. It counts as members “victims” of inaccurate polygraph readings that led to unjust job dismissals in both private companies and government service, and criminal convictions in federal courts.
Antipolygraph.org comments on the Ador-Lacson exchange: “Polygraph duels are a poor way to establish who is lying. The “test” has an inherent bias against the truthful, yet is easily defeated by the deceptive.”
In the US, after which Philippine law enforcement agencies largely pattern their investigative processes, there is a growing consensus among pro- and anti-polygraph tests that a lie detector machine cannot fully and accurately determine if a person is telling the truth.
This is because the readings of a lie detector machine are based on physiological factors that vary from person to person and are therefore unreliable. These factors are breathing, skin conductivity, and blood pressure.
This means that if a person is telling the truth, but, owing to
nervousness, he pauses before a breath, his palms sweat, and his pulse becomes jumpy during the interview—considered by investigators as telltale signs of lying—the machine will produce charts that would show that the person is, well, lying.
It follows that if a person is lying, he could be declared honest based on polygraph results if, according to Antipolygraph.org, he is able to do the following during the interview:
• Identify which questions are irrelevant, relevant, and controlled, and then give the acceptable, not necessarily truthful, answers.
• Manage to adopt a breathing pattern that is different from what polygraphers associate with deception.
• Be familiar with, and then manipulate, nonverbal language that polygraphers associate with truth and deception.
The American Polygraph Association (APA), with which some Manila-based companies offering investigation services are affiliated, maintains, however, that polygraph readings are “highly accurate.” It cites various studies it has conducted whose results showed accuracy rates of between 80 and 98 percent.
The APA acknowledges that polygraph readings are “not infallible and [that] errors do occur.” It also admits that studies show conflicting results on whether “false negatives” occur more frequently. A “false negative” is when a deceptive examinee is reported as truthful.
In the US, three segments of society use the polygraph: law enforcement agencies (on crime suspects and witnesses), the legal community (also on crime suspects and witnesses), and the private sector (on applicants for jobs). Recruits of the Federal Bureau of Investigation, as well as employees of America’s weapons laboratories, are also subject to such tests.
THE POLYGRAPH TRAP
In the Philippines, law enforcement agencies are the ones primarily using polygraph tests, but private companies are starting to turn to them for screening applicants or employees. Truth Verifier Systems Inc., the first lie detector test company in the Philippines, says its clients include private companies, but declines to identify these.
As in the US, results of polygraph tests are often rejected in Philippine courts as evidence of guilt or innocence. So why administer the test in the first place?
Justice Secretary Hernando Perez, discussing with reporters the results of Ador’s lie detection tests, said that while these were “not conclusive,” they could still help prosecutors determine whether the civilian agent would be useful in building a criminal case against those he had implicated.
Considering the growing list of people whom Ador has implicated, one wonders who will be the next to fall into the polygraph trap to salvage his or her “honor and integrity.”