Myths About Lie Detector Tests You Should Stop Believing

Polygraph testing has been around for well over a century. Interestingly, many people remain oblivious of how the technique works. This explains all the myths and misconceptions surrounding lie detector tests. 

Besides, many polygraph opponents spread unfounded rumors to discredit the technique’s efficiency. Most of these allegations touch on lie detector credibility, while some cite the potential for human rights violations. 

While certain concerns may be genuine, fierce polygraph critics will readily misrepresent facts to portray the technique as unreliable.

If you’ve considered undergoing a lie detector test but weren’t sure if it works, this post is for you. We’ve put together the eight most pervading myths about polygraphs to help you understand the technique better.

1. Polygraphs Detect Lying Directly

This is arguably the most prevalent myth about polygraph exams. 

But a lie detector test doesn’t discern lying directly. Rather, it measures physiological arousal consistent with deception. 

Studies have shown that lying stimulates the autonomic nervous system (ANS). This causes a spike in various ANS-regulated functions, notably heart rate, blood pressure, breathing, and skin conductivity. 

To infer deception, examiners compare the difference in physiological arousal during the in-test questioning with pre-established baseline data.

2. Polygraphs Can Read Your Mind

The polygraph is not a mind-reading tool. As noted, the machine measures the levels of physiological arousal associated with deception. 

A polygraph examiner isn’t trying to invade your conscious or subconscious mind. So, you can rest assured your most cherished fantasies won’t come to the fore. 

However, many pundits recommend integrating mind-reading technologies like electroencephalogram (EEG) into polygraphy. 

By measuring brain waves like the P300 waves, EEG might provide useful insights into how the brain suppresses the truth. Examiners can then use such data to improve the outcome of future polygraph tests.

Photo Credit: Polytest.org

3. Nervousness Implies Deception

Contrary to the misconception, the polygraph machine doesn’t measure mental stress. That means nervousness isn’t necessarily an indication of deception. 

In fact, most people would feel a bit jittery at the prospect of getting questioned about a crime. That’s despite their guilt or innocence. 

Nervousness during lie detector tests may also be due to improper examinee preparation. Besides, innocent subjects may become anxious for fear of false positives.

4. Only Guilty People Fail Polygraph Tests

Gary Ridgway, better known by the macabre title “the Green River Killer,” is a classic case of polygraph’s limitations. 

The serial killer passed a lie detector test and went on with his murderous rampage until DNA evidence linked him to the crimes years later. 

More recently, American cyclist Tyler Hamilton admitted to passing anti-doping lie detector tests in his 2012 book. 

The best way to minimize false negatives is to have all polygraph tests conducted by a licensed examiner. 

5. You Can Beat Polygraph Tests With Countermeasures

Countermeasures are tactics used by polygraph examinees to manipulate the test. Although common with guilty subjects, innocent individuals may also deploy these strategies in an attempt to pass polygraph exams. 

Countermeasures can be;

• Physical, such as fist clenching and lip biting
• Mental/Emotional, such as breaking down during tests
• Pharmacological, such as using antidepressant medications

Despite their popularity, countermeasures won’t help you beat a lie detector test. Your best bet is to answer every question truthfully. 

Polygraph question design rules also make the tests difficult to cheat. By comparing the magnitude of physiological response to relevant and control questions, examiners can infer deception even when a subject uses countermeasures. 

Besides, many examiners will directly ask about using countermeasures. The fact that this question is usually unexpected means it can throw an examinee off balance and uncover their underhanded tactics.

Photo Credit: Polytest.org

6. Polygraphs Are Only Used In Law Enforcement

One of the most stereotypical images of lie detector tests is that of a mean-looking examinee grilling a criminal suspect in a tiny, poorly-ventilated room, with detectives closely following the proceedings. 

But unknown to many, polygraphs aren’t exclusive to law enforcement. The technique is applicable in several other areas.

Examples include government contracting, counter-surveillance, immigration, event competitions, relationship counseling, and addiction treatment.

7. Polygraphs Are Highly Unreliable

No lie detector test can be 100% accurate. However, the tests can come remarkably close if professionally administered. 

According to the American Polygraph Association (APA), previous studies have shown that single-issue polygraph techniques can reach impressive accuracy scores of 95% or higher. 

Single-issue polygraphs investigate specific incidents. They typically target theft in the family, sexual harassment among peers, disputes between business partners, etc.

8. Polygraph Reports Are Inadmissible In Court

Polygraph findings are generally inadmissible in criminal judicial proceedings. That’s because the technique still falls short of the Daubert standard. 

However, some courts may allow lie detector reports in specific circumstances. The test findings are typically admissible in civil cases and upon both parties’ consent. 

In the United States, the polygraph’s admissibility varies from state to state. 

Most other countries lack robust lie detector laws, often relying on the APA’s standards for guidelines.

Photo Credit: Polytest.org

Information Is Power: Debunking Polygraph Myths

There you have it. By debunking these myths, we hope you can proceed to schedule a lie detector test from a point of better information. 

Remember that not all polygraph myths are fueled by the sheer misinformation about the practice. Some are due to deliberate attempts to distort well-established facts on the technique’s reliability. 

Whether you’re an examiner or examinee, it’s important to have as much polygraph information in your back pocket as possible. This will help you approach each test with an open mind and manage your expectations accordingly.