Polygraphs Essay

Cheap Custom Writing Service

Polygraphs, commonly referred to as lie detectors, are electronic instruments commonly used during pre-employment background investigations and in criminal investigations, although on a more limited basis. The ethical issues pertaining to polygraph use are essentially deception, coercion, and justice. Additionally, for polygraphs to be used ethically, the competency of the examiner and the morality of the investigator using the results are serious matters. This discussion will briefly explain polygraphs and their use, moving to a discussion of ethical issues surrounding their use, and concluding with a brief discussion of means to mitigate ethically questionable practices related to polygraph use.

Lying may be defined as making false or misleading statements for purposes of deception. One may lie to protect one’s self or another, one may lie for personal advantage, and one may even lie to be humorous. Lying is generally regarded as unethical, if not sinful, because it destroys trust, the most fundamental basis for all peaceful human interaction. Be that as it may, lying is doubtless as old as civilization and because of the necessity for truth in social relations, it is likely that techniques for detecting lies are as old as lying itself. Although historical techniques for determining veracity doubtless met with some measure of success, most likely as a bluffing tool to coerce what at least appeared as truth, these techniques were of questionable reliability.

Nowhere is there a greater need for truth than in criminal justice operations. Practitioners must be honest people and the success of the justice process is completely dependent on the ability of practitioners to determine the truth in all cases. Perhaps more than any other reason, the development of modern, professional policing drove a perceived need to develop a scientific tool for detecting deception in regard to interrogations of criminal suspects. What was desired was an instrument, the design and operation of which were based in sound science, that would give reliable, accurate assessments of a person’s honesty and would not cause harm or rely on undue coercion.

It must be remembered that throughout the 19th and early 20th centuries, what would now be regarded as extreme coercion (for example, beatings, simulated hangings, deprivation of food and sleep) was commonly used to persuade suspects to ”come clean” by confessing their guilt to investigating officers. Such methods were not only abusive of basic human rights, but also were often ineffective and generally unreliable. They were certainly not compatible with the rising police professionalism movement of the early 20th century. Scientific advances during the early decades of the 20th century and collaboration between scientists and police agencies led to the development of the modern polygraph in the 1920s and 1930s.

A polygraph is an electrically operated instrument that when properly attached to the subject of an interview measures certain physical responses of that individual during the interview process. Specifically, most polygraph instruments measure heart rate, blood pressure, respiration rate, and ”galvanic skin response,” that is, perspiration. The premise is that when one speaks truthfully, there will be little to no measurable change in these physiological processes; when one lies, one’s guilt (conscious or not) or apprehension at being caught in a lie triggers a physical reaction beyond the conscious control of the individual. Thus, the polygraph operator may determine through observation of changes of these physiological responses the probability that the subject of the interview is attempting to deceive or is lying outright. This is a critical point in terms of ethics; polygraphs do not detect lies or deception, per se. They merely report physiological changes in the subject of a formal interview. Although it is a matter of objective science that such physiological changes are closely associated with deception, it is the polygraph operator’s subjective determination of the likelihood the subject was attempting to deceive through lying, embellishing the truth, or telling only part of the truth. Although the examiner makes this determination using a probability scale based in scientific research, it is still a subjective judgment. After the examiner renders a judgment, it is the responsibility of an investigator to determine how the probability of deception as stated in the examiner’s report is to be used toward a given end. Since nothing is definitive, the possibility of abuse is strong.

It is still considered questionable whether polygraph examinations rest on valid scientific principles. There is no consensus among scientists that this is indeed the case. Some persons become quite nervous and upset merely because they are suspects and are sitting for a polygraph and will thus show physiological responses associated with lying purely due to a generalized nervousness or fear. Others may show apprehension because of the remembrance of past issues that that are induced by the questions or merely the context of the interview. Other persons, for a variety of reasons, can lie and not experience changes in physiological responses significant enough to draw even an experienced polygraph examiner’s notice. For example, persons with certain health issues, such as high blood pressure, cannot be reliably polygraphed. It is also widely believed that true psychopaths, a group that make up a larger percentage of the population than most people are aware, can lie and pass a polygraph as they feel no guilt for their actions or fear of having their lies exposed.

Criminal Investigations

As a result of these and other factors, many states make polygraph results inadmissible in criminal trials or severely restrict their use in such trials. No states, however, place statutory limitations on the use of polygraphs as investigative tools. That is, an investigator may base an investigation on polygraph results but cannot use polygraph results as the basis of her or his case presentation. The officer may use polygraph results as a means of prioritizing suspects, clearing some while determining which ones to focus the investigation on. The investigator may also use the polygraph as a tool to obtain an admission or confession from an uncooperative suspect. Such use of polygraph results is coercive and thus must be used ethically.

When a polygraph eliminates a guilty suspect after an investigator’s further consideration, an obvious miscarriage of justice has occurred whether the investigation then focuses on some innocent person or not. This may occur through honest error on the part of the examiner or because of a malfunctioning machine, a suspect who is a very good liar or possibly psychopathic, an inconclusive set of readings, or incompetence or corruption on the part of the examiner. The investigator may then perpetrate a miscarriage of justice due to simple error based on an erroneous report, an inability to understand the polygrapher’s report, a refusal to give up preconceived notions as to the guilty party in the case, or, again, incompetence or corruption on the investigator’s part. Regardless of the human factor, reliance on a machine has led to injustice.

The reverse is true as well. The human factor may cause operator misinterpretation resulting in an investigator focusing on an actually innocent person. Even in cases where the innocent suspect is eventually exonerated, that exoneration will rarely if ever occur before that person has suffered serious personal and social repercussions. At the least the person will suffer humiliation, loss of social status, and probably serious financial loss in the process of negating the suspicion caused by the polygraph. Such injustice may be the result of the human factors previously discussed.

Pre-Employment Background Investigations

Over the past several decades it has become increasingly common for police departments to require applicants for sworn positions in particular to pass a polygraph as part of the pre-employment process. Generally, the polygraph is used to verify statements made in a written application or personal history form as a means of determining the applicant’s essential honesty, something that seems ethically innocuous. Unfortunately, it has become increasingly common for agencies to replace much of the pre-employment background investigation (e.g., interviews with associates and family of the applicants) with a polygraph examination. The reason is simple economics: a thorough background check can cost many thousands of dollars; a polygraph, if done within the agency using paid agency personnel, essentially costs nothing.

The problem is that a polygraph simply cannot replace a thorough background investigation. In addition to the inherent problems related to the validity of polygraphs, there are many factors that should be considered in determining a candidate’s suitability for a law enforcement career, and many dimensions to those factors, that a onedimensional means, such as a polygraph, cannot be the basis for a fair assessment. Due to such misapplications of the polygraph it is certain that well qualified persons have been passed over for police employment to the detriment of the agency and community, as well as to the potential employee. It is also certain that less suitable persons have been hired as the result of the polygraph when a more thorough, multidimensional background investigation would have weeded them out.

Internal Affairs Investigations

Many agencies will require a citizen filing a complaint against a police officer to undergo a polygraph exam under certain circumstances and will always require the citizen to undergo the exam prior to requiring the officer to do the same. Since a high percentage of the population has little knowledge of polygraphs and the polygraphing process, particularly those from impoverished backgrounds, such requirements may have a serious “chilling effect” on the complaint process, thus allowing rogue officers to abuse citizens with some impunity.

Examiner Qualifications

The qualification process for polygraph examiners is not standardized. Most states require a license based on training credentials and state licensing board exams. Training requirements for licensure vary widely by state. Additionally, a surprising number of states do not require licensure, and thus having no statutory standards enables one who is so inclined to purchase a used machine through an online auction, for example, and go into business. While variations in standards are perhaps unavoidable, such variation will cause disparity in practice from state to state and thus disparities in the justice process whenever polygraphs are used as an investigatory tool. The fact that many investigators have only an imperfect understanding of polygraphy can only complicate the search for truth in the justice process.


  1. Bok, Sissela. Lying: Moral Choice in Public and Private Life. New York: Vintage, 1999.
  2. Carlucci, Marianna E., Nadja S. Compo, and Laura Zimmerman. “Lie Detection During High-Stakes Truths and Lies.” Legal and Criminological Psychology, v.18/2 (2013).
  3. Ellenberg, Cooper. “Lie Detection: A Changing of the Guard in the Quest for Truth in Court?” Law & Psychology Review, v.33 (2009).
  4. “Truth About Lie Detection.” New Scientist, v.25 (June 2011).
  5. Vrij, Aldert, Pär Anders Granhag, and Samantha Mann. “Good Liars.” Journal of Psychiatry & Law, v.38/1–2 (2010).

This example Polygraphs Essay is published for educational and informational purposes only. If you need a custom essay or research paper on this topic please use our writing services. EssayEmpire.com offers reliable custom essay writing services that can help you to receive high grades and impress your professors with the quality of each essay or research paper you hand in.

See also:


Always on-time


100% Confidentiality

Special offer!