Polygraph Testing


In this paper, I will analyze the “Polygraph Testing” audio case study in which Aldrich Ames, a former CIA officer turned KGB double-agent, altered the outcome of the examination in his favor. I will explain how a polygraph works, what it’s strengths and weaknesses are, how the polygraph operators allowed Ames to ‘cheat the system,’ and what Ames did to falsely pass the test. Then, I will provide a brief history of the polygraph and its use in the workplace and discuss, in detail, what it would take to effectively administer a successful polygraph on myself, who is fully aware of the science behind it, as well as the many methods in which an individual can tamper with the results.

Polygraphs, or better known as lie detector tests, are a method to decipher if an individual is lying or telling the truth through the use of monitoring their psychological and physical changes during a question and answer phase. A polygraph can measure a variety of signals, including a person’s breathing rate, pulse, blood pressure, perspiration, skin conductivity, and movement in the arms and legs. During a polygraph test, an individual is asked a few simple questions to establish their body’s typical response, often with a control question, which attempts to excite or add stress to the individual. Next, the real queries are asked, followed by an examination of the polygraph data in which the changes in the person’s vital signs are examined to locate and identify fluctuations.

In the “Polygraph Testing” audio case study, Aldrich Ames, a former CIA officer turned KGB double-agent, showed how to effectively alter the results of a polygraph by merely applying a bit of psychology and emotional control. As you hear in the audio case during the first round of questions, Ames emits a low level of interest and enthusiasm in each of the questions until he is asked about the car purchase. Once the car is brought up, his body responds to the question with fear or excitement, thus showing that he might be lying.

By not only allowing Ames to retake the test, but informing him of when he would take it, he figured out which question he failed, and accordingly, used this information to falsify the passing of the test. During the second polygraph, Ames maintained an enthusiastic attitude during each question, thus elevating his heart rate and creating a high-excitement baseline. When asked the personal finance question about purchasing his car with his own funds, his level of excitement noticeably dropped. The tone of his voice while answering the question about the car purchase was normal, thus showing a significant drop of blood pressure and respiration, which leads to passing the question under the grounds that if we were lying, his vital signs would have gone up during the specific question, not down.

Since polygraph tests rely on an individual’s fluctuations in heart-rate/blood pressure, skin conductivity, and respiration when they are asked questions, controlling how you and your body responds to the questions can allow anyone to pass the test (if correctly performed). During the exam, at least from what was offered in the short audio case, I didn’t hear a CQT (Control Question Test) asked. A CQT is a test question designed to monitor the effect of questions that would undoubtedly cause tension, such as, “Did you kill your father?” Asking a CQT would help solidify the cause of Ames being able to pass the second round of questioning, as they would have something to reference his fluctuations when asked the control question vs. the question in which he might be lying.

The reason that polygraph tests are controversial in the authenticity of their results is due to the inability to accurately measure patterns of physiological reactions. For example, an individual telling the truth in a series of questions may, at the core, be a nervous individual, thus resulting in high blood pressure during the exam. On the other hand, an individual who is lying in a polygraph may be accustomed to the act, thus allowing him to answer the questions with minimal stress or excitement.

Faking results in a polygraph can also be achieved by altering your breathing and thinking pattern when asked control questions, attempting to show increased/decreased activity during a question that should typically increase/decrease excitement. Then, when asked a question that an individual lies about, he/she can answer ordinarily without showing similar results to the control question. Alternatively, by merely causing yourself pain during control questions, you can spike your heart rate (like in the movie “Ocean’s Eleven.”) An individual can bite their tongue or curl and press down on their toes to cause pain during specific questions, thus increasing their vital signs. The use of a tranquilizer or some other medication that slows your vital signs could also theoretically alter the polygraph’s success in detecting a lie, as your vital signs and reactions to control questions would be significantly reduced due to sedation.

The real benefit of a polygraph is merely the threat it poses to someone who is being interrogated, creating fear in the subject due to being caught in a lie and potentially going to prison, getting fired, or another unsatisfactory result; due to this, the effectiveness of a polygraph depends on many factors which can’t be enforced. For example, just the polygraph operator’s tone of voice can impact the heart rate of the individual being tested. Furthermore, the setting in which the exam is performed, the nature of the control questions, the time of the day, whether the subject has eaten or slept well, the implications of what will happen if the subject fails, if the subject was notified the exam would take place ahead of time, and if the subject is allowed to retake it if they fail, all change the possible outcomes and validity of the results of the polygraph. Just the thought alone of a device that can “detect lies” is enough to intimidate many people, strengthening the coercive efforts of the interrogators.

The polygraph’s first notable contact with the legal system was in 1923, when William M. Marston, the inventor of the discontinuous systolic blood pressure test for the detection of deception, attempted to use the results of a polygraph test as evidence. John Larson, who worked for Berkley, California’s police department through the 1920s, performed the majority of early polygraph research on real police cases (Carte & Carte, 1975). Polygraphs throughout history, have played an essential role in many organizations when issuing security clearances or when used in the court of law. In 1983, U.S. President Ronald Regan issued the National Security Decision Directive 84, which enabled all federal agencies to use polygraphs/lie detectors, to test if any employees had leaked information. (Brooks, 1985; US Congress, 1983). It took only three months for Directive 84 to be rescinded; however, in 2015, the U.S. Intelligence Community once again gained the ability to use the polygraph. The Employee Polygraph Protection Act (EPPA) prohibits the majority of private organizations/employers from using lie detectors for either pre-employment or while employed. While the results of polygraph tests can be altered by those who understand how the machine works, polygraphs, in conjunction with other means of finding the truth, can be quite valuable.

If I were to be polygraphed, to achieve optimal results, I would have to be administered the exam without prior notice. Also, I would want the test to consist of multiple control questions to establish an accurate baseline of how my body/mind reacts to specific questions. For example, if they were trying to get an honest answer for one particular item, they would need to understand how high my blood pressure rises when asked either an offensive or odd question. I would imagine that it would be difficult to obtain a baseline reading on myself as I am prone to anxiety in exams. I wouldn’t be surprised if all questions asked, including control questions, produced the same reactions on the polygraph, as my heart and breathing rate would remain high during the entire test; knowing this, I could merely attempt to slow my breathing and reduce my stress during only the control question or any question in which I would need to lie to answer.

Since I realize how to trick a polygraph, the exam would have to pay close attention to my general attitude, keeping a watchful eye on any fluctuations of my personality or excitement. Like in the audio case, I can change my entire demeanor and personality before I even enter the door. By increasing the volume of my voice and speaking with more enthusiasm, I can offset the dramatic change from my resting state to excited state when asked a question that I would lie about. Furthermore, since pain can trigger an increase of heart-rate/blood pressure, a thorough search of my belongings/body would remove the ability to conceal something in which I could use to alter my physical response when asked control questions, thus aiding me in my goal of falsifying the results of the polygraph. Finally, to achieve the solidarity that my vital signs were not altered, I would recommend performing a full-panel drug test to search for any form of a mood stabilizer or sedative.

Polygraphs are not a completely accurate instrument to decide whether an individual is telling the truth; however, while it can provide benefits in an interrogation, Aldrich Ames made it quite clear how simple it was to effectively alter results. Through the use of Ames’ knowledge of how a polygraph works, the motivation to use that knowledge to beat the test using psychology and emotion control, and the ability to retake the test after failing the first time, Ames proved how simple it truly was to defeat a lie detector. Today, polygraph tests in virtually every jurisdiction are not admissible in the court of law; however, they can still be found in the interrogation process as a method of intimidation during a criminal investigation.


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Kozel, F.A., Padgett, T.M. & George, M.S. (2004). A Replication Study of the Neural Correlates of Deception. Behavioral Neuroscience, 118(4): 852-56.

Brooks, J. (1985). Polygraph testing: Thoughts of a skeptical legislator. American Psychologist, 40(3), 348–354. doi:10.1037/0003-066X.40.3.348.

US Congress. (1983). Scientific validity of polygraph testing: A research review and evaluation –A technical memorandum. Washington, DC: Office of Technology Assessment, OTATM- H-15.

Carte, G. E., & Carte, E. H. (1975). Police reform in the united states: The era of August Vollmer, 1905–1932. Berkeley, CA: University of California Press.

Employee Polygraph Protection Act (EPPA). (n.d.). Retrieved December 10, 2019, from

Lykken, D. (1998). A Tremor in the Blood: Uses and Abuses of the Lie Detector, 2d ed. New York: Perseus.

Saxe, L. & Ben-Shakhar, G. (1999). Admissibility of polygraph tests: The application of scientific standards post-Daubert. Psychology, Public Policy and the Law, 5(1): 203-23.

National Academy of Sciences (2002). The Polygraph and Lie Detection. Washington, DC: National Academy Press.


Categories: Security

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