Lie Detector Tests and Pathological Liars: Can They Be Detected?


Human communication is a complex phenomenon, and sometimes it can be challenging to discern truth from lies. Pathological liars, in particular, possess a remarkable ability to deceive others with their false narratives. As a result, various methods have been developed over the years to detect lies, with the lie detector test being one of the most well-known. In this blog post, we will explore whether a lie detector test can effectively catch a pathological liar, highlighting the role of skilled examiners in the process.

Understanding Pathological Lying

Before delving into the effectiveness of lie detector tests, it is crucial to understand the nature of pathological lying. Pathological liars are individuals who habitually lie and deceive others without apparent reason or motive. Their lies can be grandiose, elaborate, and convincingly delivered, making it challenging to identify their deceptive behavior. Pathological lying is often associated with personality disorders, such as narcissistic personality disorder or antisocial personality disorder. These individuals may lie for attention, to manipulate others, or to bolster their own self-esteem.

The Lie Detector Test

Lie detector tests, also known as polygraph tests, are designed to measure physiological responses such as blood pressure, heart rate, respiration, and skin conductivity. These tests are based on the assumption that lying induces stress, which can be detected through specific physiological changes. During a lie detector test, various sensors are attached to the individual, and their physiological responses are recorded while they are asked a series of questions. These responses are then analyzed to determine the likelihood of deception.

The Role of Skilled Examiners

While lie detector tests can provide valuable insights, the skill and expertise of the examiner play a crucial role in accurately identifying deceptive behavior, especially when dealing with pathological liars. Skilled examiners are trained to interpret physiological responses and analyze patterns of behavior to differentiate between truth and lies. Their ability to ask probing questions, detect inconsistencies, and observe non-verbal cues is vital in catching a pathological liar.


Skilled examiners understand that a lie detector test is not a standalone tool but rather part of a comprehensive assessment process. They consider the individual’s background, context, and psychological factors while analyzing the test results. Additionally, they are aware of the limitations of lie detector tests and the potential for false positives or false negatives. A skilled examiner knows how to navigate these challenges and uses their expertise to provide a more accurate interpretation of the test results.

Signs of Deception

Pathological liars may exhibit signs of deception, even though their ability to deceive is highly developed. Skilled examiners can observe changes in physiological responses, such as increased heart rate, perspiration, or fluctuations in skin conductivity, during moments of potential deception. However, it’s essential to note that these physiological changes can also occur due to other factors, such as anxiety or nervousness, which may not necessarily indicate lying.


Furthermore, skilled examiners pay attention to non-verbal cues and behavioral patterns that may suggest deception. Pathological liars may display subtle signs, such as fidgeting, avoiding eye contact, or inconsistent verbal responses. They may also exhibit signs of discomfort or defensiveness when confronted with certain questions. These behavioral cues, combined with physiological responses, provide additional information for the examiner to assess the veracity of the individual’s statements.

Challenges in Detecting Pathological Liars

Despite the expertise of skilled examiners, pathological liars can be highly adept at manipulating their physiological responses and concealing signs of deception. Their ability to remain calm under pressure and their extensive practice in lying can make it challenging for even the most experienced examiner to catch them in a lie.

Psychological Factors

It is important to consider the psychological factors that may affect the outcome of a lie detector test. Pathological liars often display traits such as charm, charisma, and confidence, which can mask their deceptive behavior. They may be skilled at creating believable narratives and maintaining a consistent story. Moreover, their own belief in their lies can lead to reduced physiological responses, making it harder to detect signs of deception.


While lie detector tests can provide valuable insights and potentially aid in catching a pathological liar, their effectiveness ultimately depends on the skill and expertise of the examiner. Pathological liars present a unique challenge due to their advanced ability to deceive and manipulate physiological responses. Therefore, it is crucial to consider additional factors, such as psychological traits and behavioral cues, in order to accurately identify their deceptive behavior.