¶ … Detecting Deception Polygraph Testing: A Critique

One of the most commonly used methods for detecting deception is the polygraph test. This is a procedure that combines skillful questioning techniques with physical measurements in order to determine stress levels that would indicate the presence of deception. It is widely used and is reliable enough to be used in a court of law, if it is properly handled and interpreted by an expert in the field. New advances are taking this same base for technology and increasing its scope and range. However, there are issues of reliability that do come up, especially in regards to when a suspect uses counter measures to throw off the test. Thus, polygraphs are excellent tools for detecting deception, but should not be trusted entirely on their own. Instead, they should be used in a combined effort with other interviewing techniques to really be effective in detecting deception.

Discussion

Using a lie detector test to determine if an individual is in deed telling the truth is one of the most popularly used method for evaluating truthfulness. It has been around for decades now, every since it was first invented in the early 1920s. According to the readings, "the best known of the psycho-physiological techniques is the polygraph, which measures heart rate, skin conductance and respiration while a person is answering a number of questions" (Cooper et al., 304). The test itself was invented by a police officer, showing its roots in criminal justice. During the procedure, a suspect is asked a series of questions. Many of these questions are purposely simple in order to set a baseline for potential lies. Tings like what is your name and other simple questions are asked fist in order to allow the person administering the test to see how the person reacts to honest answers. These baseline questions are then compared to more loaded questions,...

In fact, it measures physical changes in an individual when asked to respond to certain questions. Yet, "the polygraph does not detect lies, it detects stress" (Cooper et al., 304). Things like heart rate, blood pressure, and breathing rate are all measured in order to detect any possible changes or reactions caused by being asked an uncomfortable question, where the suspect would then try to lie or avoid telling the truth. Thus, "the pretest interview is designed to ensure that subjects understand the questions and to induce a subject's concern about being deceptive" (American Psychological Association, 2014). The science of this is based on the reaction most individuals have to loaded questions and the stress they feel as they are about to lie. When an individual tries to lie, their stress rises. This is what is being detected by the polygraph. Examiners "today use computerized recording systems. Rate and depth of respiration are measured by pneumographs wrapped around a subject's chest. Cardiovascular activity is assessed by a blood pressure cuff. Skin conductivity (called the galvanic skin or electrodermal response) is measured through electrodes attached to a subject's fingertips" (American Psychological Association, 2014). All of these measurements can be used to thus infer the presence of deception.
Trained experts then interpret the readings to determine when, if any, lies are being told. These experts often used standardized tests ad questioning techniques during the course of a polygraph session. First, there is the Control Question Test, or the CQT. According to the research, this The CQT compares responses to 'relevant' questions (e.g., 'Did you shoot your wife?'), with those of 'control' questions.…