Table of Contents
Introduction
Polygraph testing, a tool commonly associated with detecting deception, has seen significant advancements since its inception. One such development is the Directed Lie Comparison (DLC) method, a technique distinct from traditional Probable Lie Comparison Questions (PLCs). DLCs were first conceptualized in the 1960s by Lloyd “Rusty” Hitchcock, a retired U.S. Army Warrant Officer and a graduate of the U.S. Army Polygraph School.
What are Directed Lie Comparison Questions?
Directed Lie Comparison Questions are an integral part of polygraph testing methodologies used to enhance the accuracy of the test. Unlike PLCs that often involve crafting questions based on probable lies, DLCs involve instructing the examinee to intentionally lie to specific trivial questions. This method is believed to create a more straightforward, standardized testing process, minimizing the psychological manipulation of the subject.
The Rationale for Using DLCs
The adoption of DLCs in polygraph tests offers several advantages:
- Standardization: DLCs are more uniform, making the test easier to administer and the results more reliable.
- Simplicity in Administration: These tests are straightforward and involve less manipulation of the examinee, reducing the likelihood of testing errors.
- Transparency: The straightforward nature of DLCs makes them easier to explain to non-specialists, including juries, lawyers, and judges, thus potentially increasing their courtroom acceptability.
- Cognitive Demand: According to research, DLCs demand more cognitive effort from innocent subjects, enhancing the differences in responses between guilty and innocent parties.
Development and Historical Use
DLCs were developed as part of a strategy to improve polygraph testing’s effectiveness, particularly in sensitive security settings. Their use was notably implemented during the Vietnam Conflict for intelligence screenings. Over the years, studies conducted by Dr. Gordon Barland in 1981 and subsequent research through the 1990s by Drs. Honts, Raskin, Kircher, and others have demonstrated the effectiveness and improved reliability of DLCs in various testing environments, including security and criminal investigations.
Implementation in Modern Testing
DLCs are incorporated into numerous testing protocols, such as the Test for Espionage and Sabotage (TES) and the Directed Lie Screening Test (DLST). These tests have shown high accuracy and sensitivity in detecting deception, confirming the benefits of DLCs in reducing problems associated with PLCs.
Training and Best Practices
Proper implementation of DLCs requires skilled, experienced examiners who understand the nuances of this approach. Training focuses on recognizing specific, significant physiological responses and avoiding over-reliance on any one question type. Examiners are trained to manage the DLCs carefully to avoid potential biases or errors that could compromise the test’s integrity.
Conclusion
Directed Lie Comparison Questions represent a significant advancement in polygraph technology, offering a more standardized, less intrusive method of detecting deception. Their development by Lloyd Hitchcock and subsequent refinement by researchers have made DLCs a valuable tool in both security settings and criminal investigations. As polygraph technology continues to evolve, the role of DLCs is likely to expand, further enhancing the accuracy and reliability of lie detection methodologies.
