Polygraph Test Effectiveness in Law Enforcement - PSYC 3500

This essay critically examines the effectiveness of polygraph tests as a tool for lie detection in criminal investigations and forensic psychology. The paper explores the validity and reliability of polygraph tests, referencing research that questions their accuracy due to the lack of a proven relationship between physiological responses and deception. It also discusses the potential for misclassification, ethical concerns related to personal autonomy and privacy, and the influence of factors like nervousness. The essay acknowledges some potential benefits, such as aiding in criminal investigations, while ultimately concluding that the use of polygraph tests should be minimized due to their limitations and challenges. The essay provides a comprehensive overview of the topic, citing numerous peer-reviewed journal articles to support its arguments and analysis of the subject matter.

Running head: POLYGRAPH TEST
1
Polygraph Test
Name
Institution

POLYGRAPH TEST 2
Polygraph Test
Introduction
Ascertaining person honesty is extremely important, particularly in such major fields as
security screening, national security, judiciary as well as a criminal investigation. A polygraph
test is a tool that records some physiological changes in an individual undergoing an
investigation in an effort to get deception and the truth. Polygraph tests simultaneously records
respiratory activity, cardiovascular activity, and galvanic skin resistance. Polygraph testing is
presently being used in many countries in the fields of criminal investigations, corrections,
intelligence as well as civil matters. Indeed, the use of this instrument in the detection of the truth
and deception has been questioned based on its validity and its reliability. Reliability is the
capability of any test to be consistent. On the other hand, validity often looks at the accuracy of
the test. The purpose of this paper is to highlight some of the things that make Polygraph test an
effective instrument for investigation by law enforcement officers.
The polygraph test indeed remains an ineffective instrument for police to use in
investigations. First of all, validity remains of the essential accuracy measures that make any
instruments to qualify for universal practical application. But these instruments do not meet this
requirement. Many researchers argue that polygraphs are invalid since there is no well-developed
relationship between dishonest behavior and the test items. The physiological indicators remain
measured in this instrument, mainly as indicators of deceitfulness. But, the relationship between
deceitful behavior and physiological responses has not been scientifically proven. Therefore, a
polygraph test is invalid for the purpose. Also, polygraphs tests cannot be effectively used in
classifying dishonest and honest test subjects (Iacono & Shakhar, 2019). This often led to
misclassification of various test subjects. The critical classification errors, for example, false

POLYGRAPH TEST 3
negative and false positive, show that polygraph tests are not valid. Therefore, it is clear that the
errors of classification are the main challenges to these instruments that hijack the very goal of
polygraphs items. The reality remains that polygraph tests cannot detect the falsity or truth of a
statement. Instead, this machine measures the biological process of a person to find out if they
remain to experience any physiological events, for example, an increase in heart rate or blood
pressure (Hong et al. 2017). These conditions remain considered to be the essential indicators
that an individual may be telling the truth or lying. The truth is that there is no physiological sign
of deception. Also, there remains no scientific evidence that some of the things that polygraph
test measures such as blood pressure, breathing, and heart rate- are associated with whether an
individual is telling the truth or lying. Unfortunately, numerous factors may also affect the
readings of this instrument. For example, the nervousness of any type might read with the same
rise in activity, mainly as a lie. The nervousness might be initiated by being concerned about the
test detecting a false positive, making a self-fulfilling prophecy. In reality, many polygraph
administrators, specifically in law enforcement, are providing training on how to prompt an
incorrect positive response or to design questions in a way that makes it difficult for people to
answer with a no or yes (Yoder, Hansen & Lobanov-Rostovsky, 2018).
Conversely, most people who are taking this test have reported being capable of evading
the detection of a lie by employing numerous techniques, for example, falsifying a cold,
squeezing the posterior muscles, among others. These techniques would initiate a reading on the
machine that would display increased biological activity even when an individual is not lying.
All these can make the machine to give out inaccurate results to the law enforcement (Meijer &
Verschuere, 2017). Consequently, polygraphs have been challenged on numerous occasions in
many jurisdictions on the ground of their scientific doubt. Since the results of this machine may

POLYGRAPH TEST 4
mean many things, and they are also unreliable in identifying actual lies, Polygraphs do not show
the level of reliability needed for scientific evidence more so in a courtroom.
Additionally, there remains lack of uniformity in the kinds of polygraph examinations
used in different jurisdictions, in terms of questions used as well as the format. Numerous
jurisdictions used different questions even if the criminal activity conducted is the same.
Therefore, it is difficult to access the accuracy of the instrument as it is based on the assumption
that undesirable behaviors are signs of illegal activity. Therefore, this claim that polygraph test is
an effective as well as important treatment or management device that lowers sexual as well as
general criminal recidivism more so during treatment and supervision have no reliable scientific
basis.
It is also true that these instruments tend to generate substantial ethical problems. An
example of the fundamental ethical issues linked to the use of these instruments remains the
problem of personal autonomy of the various test subjects. Polygraphs tests remain apparent
invasion into civil liberties of people as several crime examinees and suspects are forced to use
these instruments. These instruments also encourage the invasion of the privacy of an individual.
Furthermore, interpretation of the results remains the other ethical violation experience during
polygraph testing. Because there is no empirically or theoretically established relationship
between deceitful behavior and physiological responses, some of the test administrators have a
habit of interpreting the results in a based or subjective manner that is unethical and unfair.
Even though the polygraph test remains an ineffective instrument for law enforcement
officers to use for investigation, there are some benefits associated with this instrument. Criminal
investigation indeed remains one of the key fields in which this instrument is used to detect lying
(Rajan, 2019). They provide legal systems and government agencies with a useful and

POLYGRAPH TEST 5
straightforward method to extract the actual truth from the suspects. Many researchers argue that
polygraph tests remain used by law enforcement agencies and criminal investigation teams in the
United States as well as other nations around the Universe (Vrij & Fisher, 2016). It is also true
that polygraph tests can assist the security agencies in detecting suspected terrorists as well as
other antisocial people who could disguise their identities. Therefore, these instruments remain
useful for the identification of criminal activities in the legal system as well as law enforcement
agencies.
Conclusion
A polygraph test is a kind of magical instrument that aids detect whether a person is lying
or telling the truth. The assumption behind the use of this instrument remains that the process of
telling lies is often reflected kin the neurological or physiological responses as the body of
human beings tend to react differently more so when exposed to a different environment. The use
of this instrument in different settings has proved to be problematic. Indeed, the use of a
polygraph test in the detection of the truth and deception has been questioned based on its
validity and its reliability. This instrument is susceptible to both physiological and physical
countermeasures. The main benefit of a Polygraph test is that it provides the legal systems and
government agencies with a useful and straightforward method to extract the actual truth from
the suspects. Considering all the advantages and disadvantages of polygraph test, it would be
good when security agencies and law enforcement minimize the use of Polygraph test in
detection of criminal activities. They should find strategies for reducing threats to national
security and public safety that partially rely on the polygraph.

POLYGRAPH TEST 6
References
Hong, Y. N., Jin, M. J., Gi Hong, H., Kim, H. S., Ki Ji, H., & Hyun, M. H. (2017). Attentional
bias of guilty and innocent participants in a concealed information test. Social Behavior
and Personality: an international journal, 45(10), 1585-1594.
Iacono, W. G., & Ben-Shakhar, G. (2019). Current status of forensic lie detection with the
comparison question technique: An update of the 2003 National Academy of Sciences
report on polygraph testing. Law and human behavior, 43(1), 86.
Meijer, E. H., & Verschuere, B. (2017). Detection deception using psychophysiological and
neural measures. Finding the Truth in the Courtroom: Dealing with Deception, Lies, and
Memories, 209.

POLYGRAPH TEST 7
Rajan, P. B. (2019). Polygraph Tests-Benefits and Challenges. Academicus International
Scientific Journal, 10(19), 146-155.
Vrij, A., & Fisher, R. P. (2016). Which lie detection tools are ready for use in the criminal justice
system?. Journal of Applied Research in Memory and Cognition, 5(3), 302-307.
Yoder, J. R., Hansen, J., & Lobanov-Rostovsky, C. (2018). A framework for the judicious use of
the polygraph for youth who have committed a sexual crime. Victims & Offenders, 13(1),
48-65.