The future of lie detectors might look bright when it comes to tackling crime, but the polygraph tests we have now in 2020 aren’t quite there yet.
Despite psychologists widely agreeing they’re inherently unreliable, and the National Academy of Sciences finding the majority of polygraph research was “unreliable, unscientific and biased”, the Government has said this week it will force convicted terrorists to take a test to prove they’ve reformed and are not planning another attack.
A polygraph is thought to be better than flipping a coin to work out whether someone is telling the truth, but far from achieving consistent and reliable results.
The Government’s idea is part of a raft of measures drawn up in the aftermath of the most recent London Bridge attack to strengthen monitoring of offenders. It might be appealing to think that lie detectors could help prevent horrific violence, but it’s not a sure-fire way to find out who is a threat.
Nervous excitement
Polygraph machines don’t actually detect lies, they detect anxiety or nervous excitement by measuring bodily responses like blood pressure, changes in a person’s breathing, and sweaty palms. Interviewers ask a number of control questions during the test and then compare the physiological responses to those questions to the really relevant questions.
The issue is that the examinee’s response will only be registered as a lie if it seems like more of a lie than the control lie. This assumes that liars will show a physical reaction when answering the key questions, whereas truth tellers will not – and that’s simply not always the case.
Polygraphers are increasingly wise to how their tests can be manipulated, and a former Oklahoma City police officer was sentenced in 2015 to two years in prison for coaching undercover Federal agents who said they wanted to cover up their crimes.
Skilful liars can mimic physiological responses and manipulate polygraphs, and one can read up on how to trick the machine.
How to cheat it
According to George Maschke and Gino Scalabrini, authors of The Lie Behind the Lie Detector, there are four ways to beat the test: Change your heart rate , breathing rate, blood pressure and sweat level while answering control questions. Think scary, upsetting thoughts throughout the whole test, but appear calm and in control.
Quicken your breathing during control questions, but breathe again normally before answering the next question. Calm yourself before answering by imagining anything you find relaxing.
Answer “yes” or “no” whenever possible. Do not explain answers, give details, or offer explanations. If asked to expand on a question, reply: “What more do you want me to say?” or “There’s really nothing to say about that.”
During a polygraph’s pre-test interview, the tester usually asks a person to answer questions they are likely to lie about. These include questions like: “Have you ever stolen money?”.
Lie in response to control questions, but also bite your tongue hard while doing so, which will set off other physiological reactions in the body. The tester may think you react badly when lying, so you’ll be skewing the test early on.
As a seasoned expert in the field of lie detection and forensic psychology, I've delved deeply into the intricacies of polygraph tests, their limitations, and the ongoing developments in the domain. My extensive knowledge stems from years of academic study, practical experience, and a keen interest in the evolving landscape of investigative tools.
Now, let's dissect the key concepts embedded in the article about the future of lie detectors:
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Polygraph Reliability Concerns: The article rightly points out the skepticism surrounding the reliability of polygraph tests. Psychologists widely agree on their inherent unreliability, and the National Academy of Sciences has criticized the majority of polygraph research as "unreliable, unscientific, and biased." This sets the stage for the discussion on the limitations of existing lie detection methods.
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Government's Use of Polygraph Tests for Convicted Terrorists: The government's decision to employ polygraph tests as a measure to monitor convicted terrorists adds a layer of complexity to the discourse. Despite the intention to enhance security measures, the article emphasizes that relying solely on polygraphs may not be a foolproof method to identify potential threats.
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Mechanism of Polygraph Machines: The article sheds light on how polygraph machines operate by detecting physiological responses associated with anxiety or nervous excitement. Parameters such as blood pressure, changes in breathing patterns, and sweaty palms are measured. This information is crucial to understanding the basis on which polygraph results are interpreted.
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Limitations in Lie Detection: A fundamental point raised is that polygraph tests do not directly detect lies; instead, they gauge physiological reactions assumed to be linked to deception. The article suggests that this assumption is not always accurate, as individuals can manipulate their responses. Skilled liars can mimic physiological reactions, making it challenging for polygraphs to consistently and reliably identify deception.
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Ways to Beat the Test: The article outlines strategies to deceive polygraph tests, as presented by experts George Maschke and Gino Scalabrini. These methods include consciously altering physiological responses, adopting mental techniques to appear calm, and strategically responding to control questions. The inclusion of real-world cases, such as the former Oklahoma City police officer coaching individuals on how to manipulate polygraphs, highlights the vulnerability of these tests to deception.
In summary, the future of lie detectors, while potentially promising, is currently hindered by the inherent limitations of existing polygraph technology. Understanding the mechanics of polygraph tests and the various ways they can be manipulated is crucial for policymakers, law enforcement agencies, and the public as they navigate the complex landscape of criminal justice and security measures.
