What is a Lie Detector Test | Polygraph Examination?

A polygraph examination, commonly known as a lie detector test, is a scientific method used to assess the reliability of an individual’s statements by measuring physiological responses. The underlying principle is that deceptive answers produce physiological responses, which the polygraph examiner differentiates from those associated with non-deceptive answers.

The polygraph machine records several physiological indices such as heart rate, blood pressure, respiratory rate, and skin conductivity while the subject answers several questions. The rationale is that lying is presumed to induce a stress response in the body, which, in turn, manifests through measurable changes in these physiological parameters. For instance, increased heart rate or blood pressure, faster breathing, or greater electrical conductivity of the skin (due to sweating) might indicate stress or deception.

The interpretation of polygraph results is subjective and relies on the examiner’s expertise. The accuracy of polygraph tests has been a topic of debate within the scientific community, as factors such as nervousness, fear, confusion, or physiological disorders can also affect the physiological responses, potentially leading to false positives or negatives. Therefore, while polygraph tests can provide insights into physiological changes during questioning, they are not infallible indicators of truthfulness.

A Brief History of Lie Detector Tests | Polygraph Examinations

In 1921, John Augustus Larson, a Canadian-born police officer and medical student, invented the polygraph in its more recognizable form. Larson’s polygraph was the first to simultaneously record multiple physiological responses, including blood pressure, heart rate, and respiration, during questioning.

Larson’s student, Leonarde Keeler, further developed his work by introducing the galvanic skin response (GSR) measurement to the polygraph in 1938, enhancing its ability to detect deception. Keeler is often called the “father of the polygraph” for his extensive contributions to popularizing the device and its methodology.

Over the decades, polygraph examinations have been refined with technological advancements and improved methodologies. Despite debates about their reliability, validity, and ethical implications, polygraph examinations have been used in various contexts, including criminal investigations, employment screenings, and security clearances.

In a BBC news article on the credibility of lie detector tests, Prof Grubin, professor of forensic psychiatry at the University of Newcastle, was quoted as saying, “If the examiner is well-trained, if the test is properly carried out, and if there’s proper quality controls, the accuracy is estimated between 80%-90%,” adding that this is higher than the average person’s ability to tell if someone is lying.

Types of Cases Lie Detector Tests | Polygraph Examinations Are Commonly Used

Polygraph Examinations for Cheating Spouse | Infidelity Investigations

A polygraph examination can be a valuable tool in infidelity investigations, offering you a means to determine the truthfulness of your partner’s statements. This method can add an objective layer to resolving doubts, facilitating clearer communication and decision-making in your relationship. Employing a polygraph test demonstrates a commitment to uncovering the truth, potentially paving the way to rebuilding trust in your relationship or informed decision-making based on the examination’s outcomes.

Polygraph Examinations for Business | Corporate Pre-Employment Screening and Security Clearances

A polygraph examination in employment screenings and security clearances is an effective vetting tool, ensuring that candidates meet the high integrity and reliability standards required for sensitive positions. The polygraph helps identify potential discrepancies in an applicant’s history or responses, highlighting issues related to honesty, past misconduct, or undisclosed activities that could pose risks. 

This process benefits you by enhancing the security and trustworthiness of your team, particularly in roles where confidentiality and ethical behavior are paramount.

Polygraph Examinations for Disputing False Allegations or Charges

A polygraph examination can be instrumental in disputing false allegations or charges. This can be particularly beneficial if you’re seeking to demonstrate your innocence or challenge unfounded accusations. While not always admissible in court, the results can influence legal strategies, negotiations, and even public opinion by lending credibility to your claims. Employing a polygraph test underscores a proactive approach to clearing your name, offering a tangible means to dispute allegations and protect your rights.

Who We Are and What We Do

Since 1990, Shadow Investigations has provided unparalleled investigative services to individuals, law firms, corporations, and insurance companies. We employ a diverse team of private investigators and a network of experts, enabling us to deliver comprehensive services tailored to your needs.

Our polygraph specialist’s credibility and expertise are unmatched. He trained at the RCMP Polygraph School in Ottawa and has been certified since 2000. As a retired 30-year Vancouver Police Department member who oversaw the polygraph section in his final years, he has conducted hundreds of polygraph examinations across various issues with extensive experience and a proven track record for achieving results.

Lie Detector Test | Polygraph Examination Fees

Our Polygraph Examination Process

Step 1: Schedule
Discuss your situation with our polygraph examiner to identify the objectives in a free, no-obligation consultation. Then, you can get all your questions answered and decide if it’s a good fit.   

Step 2: Examination Process
The polygraph examination consists of 3 distinct phases: a pre-test, an in-test or data collection, and a post-test.

• Pre-test: The examiner completes paperwork, assesses the examinee’s suitability, and reviews test questions
• In-test: In a distraction-free room, the examiner collects data using sensors and asks agreed-upon yes/no questions.
• Post-test: The examiner evaluates polygraph charts, provides an opinion on the examinee’s truthfulness, and discusses results directly or in a written report.

Step 3: Conveyance of Examination Results
The examiner provides a written report detailing issue-related questions and assesses the examinee’s honesty during the examination.

Why Choose Us?