Polygraph technology changed the way law enforcement interrogated suspects. Before the introduction of this technology in the 1920s, law enforcement would have to rely on the evidence at hand. A suspect could lie their way through interrogation, with no way for law enforcement agents to decipher if the suspect was lying or telling the truth.

Obviously, any suspect apprehended by authorities would vehemently deny involvement with criminal activities. Unless law enforcement officers had evidence of planned or completed crimes, the suspect could lie about their involvement, and there was no way for officers or detectives to determine if they were deceptive during questioning.

When the polygraph came along, it gave law enforcement the tool they needed to assess deception in an interrogation. The polygraph measured changes in pulse and respiration rate, and blood pressure. When a subject was lying about something, these three indicators would experience a rise in baseline values.

A law enforcement official could instantly identify deceptive behavior in the suspects, allowing them to pressure the suspect with further interrogation techniques. Eventually, the suspect would crack under pressure, confessing to the crime.


Changes in Polygraph Technology

While the first 60+ years of polygraph use was the “wild west” for lie detector technology, things would change in the 1980s. Several studies circulated showing the inaccuracy of polygraph results. Therefore, authorities drafted specific legislation surrounding the use of polygraphs in law enforcement and the public and private sector.

However, advancements in polygraph technology led by the computer revolution in the 1990s saw algorithms and software introduced to optimize the polygraph process and enhance the accuracy of exam results. Still, the legislation protecting suspects and employees from undergoing polygraphs remains.

So, we have a disparity between whether the tech was in the late 1980s versus where it is today. Experts argue that modern polygraphs have a 98% accuracy rate at detecting deception. Activists against the use of polygraph technology claim it only has a 60% to 70% accuracy rating.

However, the detractors of polygraph technology base their statistics on studies from the 1980s and 1990s. This was before the introduction of algorithms and computer tech into the field. Today’s polygraph technology is nothing like that of the 1980s.


Polygraphs in the Media

The commotion caused by studies involving the inaccuracies of polygraph results in the late eighties gained media attention. Many news publications and magazines published articles introducing the concept of polygraph tech to the public, mostly in a negative light.

In a way, this was well-deserved. With an accuracy rate of 60% to 70%, convicting a criminal based on polygraph evidence alone seemed preposterous. If a person was nervous at the exam time, they might pop for deception, regardless of being innocent of the accused crime.

The media exemplified these cases, discounting polygraph tech’s overall benefit to law enforcement. However, the biggest advocate for abolishing polygraphs came from the private sector. Employers would use polygraphs in pre-employment screening to weed out bad hires.

While it made sense to use polygraphs to determine if an employee had a criminal history or intended to bring illegal activity into an organization, many employers abused the tech. Employers would use polygraphs to avoid hiring candidates they felt weren’t a good fit, using it as a tool of discrimination in the hiring process.

Employers would also use polygraphs to weed out people underperforming against expectations, firing them for supposedly failing a polygraph. Since the employer didn’t have to disclose the polygraph results to the candidate or employee, they told them they failed, even if they passed, and fired them or decided not to hire them.

The media brought this into the public eye, and suddenly polygraph technology became part of popular culture. Soon, polygraphs were seen popping up on TV and in movies. Programs like CSI and movies surrounding police interrogations displayed actors taking polygraphs.

So, how accurate is the portrayal of polygraphs in the media? Do movies correctly represent the use of this tech? Or are they doing it an injustice? Let’s unpack how polygraph looks on camera and film. We’ll look at two case studies from blockbuster movies to see how they represent the technology on screen.


Case Study – Steven Segal and “The Glimmer Man”

In 1996, Warner Brothers released “The Glimmer Man,” directed by John Gray and starring Hollywood superstars Steven Seagal and Keenan Ivory Wayans. The buddy cop movie centers around Seagal playing the part of a cop newly introduced to a police department hunting a serial killer named “the Family Man.”

Seagal’s outlandish and reckless behavior on the job leads him to be polygraphed by his department for his potential involvement in the crimes and his use of excessive force on the job. The scene in the movie involves an examiner asking Seagal a series of baseline questions.

She was using one of the older machines that recorded emotional responses on paper. This is correct since it was on the cusp of computer technology changing the polygraph industry. The setup is accurate, with Seagal sitting in a high-backed chair, looking away from the examiner.

He has a pressure cuff on his arm and with a pressure cuff on his arm, corrugated tubes around his chest, and sensors on his fingertips. However, he has the tuba and cuff over his jacket. This is incorrect. Most examiners would ask him to remove the coat due to its thickness possibly interfering with the signals. There are also three other cops in the exam room, which would be against normal operating procedures where only the examiner and examinee are in the room.

Seagal also holds Buddhist prayer beads in his hands, which would be unacceptable in a polygraph scenario. The baseline questions require yes or no answers, which the movie gets right.

Comically, one of the control questions is “have you ever climbed Mount Everest?” the control is obviously there to draw a “no” answer for the baseline. However, Seagal answers, “yes.” This draws the attention of the examiner and the other cops in the room because it reads true on the polygraph.

The examiner carries u the rest of the scene, asking questions that we would expect in such a scenario. After the exam is complete, Seagal’s superior asks the examiner if he’s telling the truth or if he may be lying. She replies, stating that he could be lying but would need total control over his emotions.

Looking at this post-exam review, it could be more accurate. Typically, the examiner would need time to review a recording of the interview and match the results to body language to his answers. This process could take 24 hours to complete.

Overall, the scene is fairly accurate, and we would give it a score of 5/10.


Case Study – Robert De Niro and Ben Stiller in “Meet the Parents”

In the 2000 smash hit, “Meet the Parents,” Ben Stiller plays the part of the soon-to-be son-in-law of Robert De Niro. He stumbles across a hidden room with spy equipment when visiting his finances parent’s home. He’s looking at a lie detector machine, similar to the model used in “The Glimmer Man.”

De Niro discovers him and asks him if he’d like to give it a go. It turns out De Niro is an ex-CIA operative, well-trained in conducting lie detector tests. De Niro seizes the chance to talk Stiller into taking the test. He straps the corrugated tubing to his chest and abdomen and places a blood pressure cuff on Ben’s arm, along with sensors on his fingers.

Stiller is sitting in a high-backed chair facing away from De Niro’s – everything is looking good so far. Before De Niro starts the questioning process, Stiller tells him, “These things aren’t that accurate, right?” De Niro responds, “You’d be surprised at how accurate they are; they can tell fairly accurately if someone’s lying or not.”

De Niro then explains the procedure of asking questions to which Ben must answer yes or no. He starts by asking, “Did you fly on an airplane today,” Ben replies, “Yes, I did.” De Niro Looks at Ben as he answers to assess his facial micro-expressions and then looks at the machine readout from the polygraph to gauge his answer while marking his response with a felt pen for true or deceptive.

This is all remarkably accurate to a real-world polygraph exam and a much better example compared to that from “The Glimmer Man.” When De Niro asks him if he like the pot roast they had for dinner, Ben must be truthful and say it was rare compared to his preference.

He’s clearly nervous, and De Niro jokes around with him, telling him to relax because the needles on the polygraph are jumping. Once again, this is all very accurate. When De Niro asks, “Have you ever watched pornographic videos?” Ben answers, “No,” and the needles on the polygraph go wild, indicating he’s lying.

Overall, this scene is accurate, so what did they get wrong? In a legit scenario, no examiner would coax an examinee into taking a polygraph in this manner. It would be highly illegal. Also, it needs to give the examinee (Stiller) more time to prepare for the process.

Other than that, it’s pretty accurate, and we would give this one a score of 8/10.


What Does the Media Get Wrong About Polygraph Exams?

Media, like movies, often make mistakes in representing polygraph technology. Most people writing scripts receive their knowledge from reading up about polygraph techniques and how they work. Very few undergo actual polygraph testing with an experienced examiner.

There are plenty of talk shows and TV series showing polygraph techniques, but all of them are done on film instead of in a personalized setting between the examiner and examinee. This setting alone is enough to skew the accuracy of results, making the examinee more nervous and resulting in inaccurate data.

In all cases, the results are staged for effect. You’re not looking at a genuine lie detector test, so it’s impossible to discern whether it’s a correct questioning procedure or the examinee is lying. Polygraphs can’t be conducted in front of live audiences, it’s against best practices and policies, and no data support what would happen in such a setting.

Polygraph exams must be conducted in controlled settings with no distractions. The accuracy of polygraph results also drops with more questions asked by the examiner. Polygraph questions are also spread over 20 to 25-second gaps to give the sympathetic nervous system time to settle between answers. This strategy allows for better accuracy in results.

Polygraph exams take 30 to 90 minutes, depending on the circumstances, and only include relevant questions. Asking someone if they watch pornographic movies would not be a pertinent question in any polygraph scenario. But it sure is funny to watch Ben squirm when answering the question.


Wrapping Up – Don’t Believe the Hype

The media does a reasonable job of portraying polygraph tests in movies and TV. However, in most cases, they do the job of demonizing the technology, giving the appearance that it’s not required because you should trust people more. However, in most cases, the use of polygraphs is surprisingly accurate.

In the cases of “The Glimmer Man” and “Meet the Parents,” both examples are surprisingly accurate, apart from a few caveats. We can’t get mad at either instance. However, they are not 100% correct despite being reasonably good examples. Polygraphing is an exact science, and any deviation from the benchmark protocol taught by the American Polygraph Association (APA) exposes the examiner, law enforcement agency, or employer to legal repercussions.

However, we’re dealing with movies and TV here, not real-world situations, so we have to give them the benefit of the doubt. Regarding the results, despite being a monk and Aikido black belt, we doubt Steven Segal could lie and get away with it. It’s also clear Stiller is a terrible liar, and the result is somewhat hilarious.

While Hollywood does a reasonable job of showing the process and results of polygraph exams, it needs to be corrected, but that’s what we would expect.