In this article, we are going to discuss the reliability of polygraph devices and their history.

Let’s talk about the introduction to the notion of lie detection, set against the backdrop of Liu Cixin’s science fiction series “The Three-Body Problem.” this concept is about the Trisolarans, an alien race who cannot lie because they broadcast their thoughts, to emphasize the difficulties humans encounter in conveying the truth. This story emphasizes the inherent difficulties of determining whether someone is lying, as people cannot access one other’s thoughts directly and must rely on indirect signs and established tactics.

But we as human beings do not have the power to see what is running through someone’s mind. We can only trust them based on their words and actions. Apart from that, we can also determine to some extent by their body language, actions, and the way they act.

Human beings have invented and developed techniques to detect if a person is lying or not.

Evolution of lie detection:

The world’s first lie detection technique dates back to the year 1000 B.C. and originates from China.

Anybody whose words were suspected to be untrue should fill their mouth with dry rice and if the rice does not get wet until the very end then he/she is considered to be lying.

The physiological theory behind this: when a person experiences anxiety or fears their mouth runs out of salivation and hence the rice won’t be wet and remains dry.

Biomarkers and Physiological Signs:

Biomarkers are modern attempts at detecting deception based on psychological factors.

Biomarkers are the changes that appear in the body of a lying person.

A polygraph device is a great example of verification to know if a person is being truthful or not. This device uses physiological signs to detect the lie. This device has been used for many years in criminal investigations to provide solid evidence.

The polygraph device uses indications such as blood pressure, heart rate, skin conductance, and breathing to detect deception.

Truth about Lie Detectors:

The significance of lie detectors is completely not effective. An individual may fail the test even if he/she is not lying. The lie detector may have confused anxiety and stress with being false.

The difference in cultural and demographic variability also plays an important role here. Physiological reactions to lying may vary by culture, ethnicity, gender, and age. The results from one group may not appropriately reflect or pertain to another, resulting in possible errors.

Jo Ann Oravec from the University of Wisconsin says, “Bias is certainly a major issue. To interpret the results of a lie detection test, the data collected are compared to other results. If those other results were conducted on people of a different race, ethnicity or gender, the analysis could indeed be faulty, and various demographic groups could suffer an increase in false positives”.

Oravec further added, “The false positives that categorize individuals as liars often have devastating economic and social implications. The individuals identified as liars are not ‘innocent until proven guilty,’ but the reverse […] they must provide support for their innocence, possibly in the form of yet another poorly-validated lie detection test”

In her recently published paper, she spoke about the ethical and functional problems of modern truth verification devices. She insists that the biomarker approach has issues related to it.

Artificial intelligence in  lie detection:

Scientists at Tel Aviv University created an AI tool in 2021 that utilizes facial expressions to assess whether or not someone is lying. This technology is said to be around 73% accurate, although people are roughly 54-60% accurate.

However there are concerns about fairness and privacy here, the AI data collects personal information and data when taking the tests and it is not yet clear how the data is handled or interpreted.

Experts are additionally researching making use of brain scans (fMRI) and machine learning to identify lying. This approach can interpret mental content with great accuracy, which has led some to believe it may be used to detect lies.

During one of the 2019 papers, experts from the University of Plymouth explained that individuals using mental countermeasures will be able to deceive fMRI-based lie detector tests. People started raising questions regarding the legitimacy of the device since it is being used for serious areas such as criminal cases.

There are both ethical and practical concerns about employing these new lie-detecting systems. Some nations already have rules prohibiting the utilization of lie-detection tools, and emerging AI technology may alter how existing laws apply.