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Polygraph testing: a utilitarian tool.

Much debate has transpired over the reliability of polygraph testing whether used in criminal, counterintelligence, preemployment, or other venues. In fact, the scientific community has not encouraged its use due to a lack of supporting evidence for reliability and validity. (1) In a 2002 report, the National Academy of Sciences concluded that the accuracy of the polygraph in distinguishing actual or potential security violators from innocent workers proved insufficient to justify reliance on its use in employee security screening in federal agencies. (2)


Critics of the polygraph have sought its discontinuance for years, calling it a "junk science" with no scientific basis. (3) In 1988, the Employee Polygraph Protection Act (EPPA) almost completely abolished the use of polygraph for preemployment and employee screening in the private sector. (4) Although the act exempted federal agencies, those in the federal polygraph community and in numerous intelligence and law enforcement organizations in all jurisdictions, including private examiners, have had to continually battle critics who seek its total abolishment.

The Debate

Time and again, the debate over the use of polygraph testing centers around its reliability and validity (or lack thereof) with little discussion from either side as to its utilitarian component. This is a common oversight neglected in the literature and ignored by those seeking to criticize an investigative technique because it is not always reliable. However, law enforcement investigators who have a commitment to the public they serve recognize the polygraph's usefulness as a tool for obtaining information not previously known in criminal investigations. Confessions gained as a result of polygraph examinations are admissible as evidence in court, providing investigators have met the rules for admissibility, such as no use of force, threats, or promises. (5) Confessions, admissions (conceding to some aspect of the crime but not the entire crime), and additional information of investigative value gained through such testing come about due to the utility of the polygraph and the determination of the examiner, irrespective of the instrument's reliability or validity.

Certainly, reliability and validity are important. Investigators do not want to waste their time with a lie detection technique that yields little more than speculative results. The point is that countless stories have appeared in newsletters and journals advocating the use of the polygraph, but little information has been published on its utilitarian value, or usefulness. Instead, the real mission of such published works seems to rest with discussing only its reliability and validity, avoiding its usefulness as a detection of deception technique.

The utilitarian value of the polygraph might surprise even the strongest critics when it comes to criminal testing and the results the device provides. In a 1996 study of 96 child support cases listed as questionable due to the unknown where-abouts of the father, the researchers informed the mothers that they would use the polygraph to verify the unknown status of the fathers. Following the mere suggestion of polygraph testing, 51 of the mothers came forward with additional information, resulting in the resolution of those cases. (6) Additionally, in 2002, three men confessed to murders following their polygraph tests. During a polygraph pretest, one man confessed to child molestation. When another man was notified that his polygraph had been scheduled, he confessed to shooting his wife. And, after failing a polygraph test, a third confessed to killing his wife. (7)

Every day, investigators from federal, state, and local law enforcement jurisdictions interview suspects, victims, and witnesses to crimes. Their primary goal is to get the truth from these individuals to bring their particular cases to a successful conclusion. Some are highly skilled at getting people to confide in them; others are not. Successful or not, they second-guess themselves and critically review their performances long after concluding their interviews. Their curiosity in these matters is never fully satisfied, and they remain "students of human behavior." (8)


The Theory

Most investigators attend in-service training seminars and conferences focusing on interview and interrogation strategies or detection of deception methodology. Despite the amount of training they receive or their experience levels, most willingly accept assistance to help bring a subject of their investigation in line with the truth. In doing so, they often turn to the polygraph, regardless of its reliability, as a tool to get the information they seek. In fact, they ascribe to the theory that the utility of the polygraph frequently will bring them additional useful information not previously known. This theory has proven successful because any technique that examinees believe to be a valid test for deception likely can produce deterrence and admissions. (9)


In an effort to further explore this theory as it pertains to polygraph testing in the criminal arena, the FBI's Polygraph Unit conducted an archival research study of 2,641 polygraph examinations from January 1, 2001 through December 31, 2003. All polygraph examinations reviewed were conducted by certified FBI polygraph examiners. The study included examinations yielding deceptive results wherein investigators obtained confessions, admissions, or information of investigative value, as well as those deceptive reports wherein no useful additional information resulted. The non-experimental study involved the review of existing records, focusing on specific aspects of those in question. Reports pulled for archival review discussed facts, information known prior to the polygraph, and additional information provided, if any, during and after the polygraph. To expose the utilitarian value of the polygraph as used in these criminal cases, the study needed to determine the significance of the polygraph technique on moving individuals from a position of deception to one of nondeception. Although some can argue what constitutes "significance," few would dispute that one out every two individuals found deceptive in a criminal polygraph examination who ultimately provided a confession, admission, or additional information of investigative value could constitute an accurate definition. Such significance certainly would indicate polygraph testing as a worthwhile endeavor to continue as a useful detection-of-deception technique.

Overall, the study showed that out of the 2,641 deceptive criminal polygraph reports reviewed, 1,316 provided no additional useful information. However, 1,325 reports resulted in acquiring confessions, admissions, or information of investigative value. Clearly, the study, solely concerned with the utilitarian value of polygraph testing, demonstrated that one out of every two subjects found deceptive by FBI polygraph examiners testing in the criminal arena provided information of value for the time period reviewed. This should encourage those who criticize a detection-of-deception technique that has a long history of success to consider its usefulness as a tool to obtain additional information. If not, perhaps they would do well to ponder a parent's worst nightmare. Your child is abducted and investigators come to you and say, "We have a suspect who we will be giving a polygraph to." Would you be so bold as to reply, "The polygraph technique is unreliable, find my child another way"?


Taking sides in the debate over polygraph testing should not blind those interested in seeking the truth in criminal cases. Polygraph testing can help law enforcement investigators obtain the complete facts and bring the guilty to justice.

Regardless of its validity or reliability, polygraph testing offers investigators another tool they can employ in interviews to help them obtain additional valuable information. In today's world of terrorists and criminals bent on destruction and mayhem, the law enforcement profession must use all of the techniques and strategies available to safeguard American communities. To deprive investigators of a tool that could, more often than not, help them solve crimes or prevent future tragedies demonstrates a lack of understanding that may have grave and far-reaching consequences.


(1) Lawrence S. Wrightsman, Forensic Psychology (Belmont, CA: Wadsworth, 2001), 108-109.

(2) National Research Council, Division of Behavioral and Social Sciences and Education, The Polygraph and Lie Detection: Committee to Review the Scientific Evidence on the Polygraph (Washington, DC: The National Academies Press, 1996).

(3) Retrieved on January 5, 2005, from

(4) James A. Matte, Forensic Psychophysiology: Using the Polygraph (Williamsville, NY: J.A.M. Publications, 1996), 83.

(5) Richard O. Arthur, The Scientific Investigator (Springfield, IL: Charles C. Thomas, 1965), 27.

(6) M.T. Hanna and D. Welter, "The Utility of Polygraph Examinations in Unknown Paternity TANF Cases," Polygraph 27 (1998): 285-286.

(7) Dean Pollina, "Polygraph in the News," American Polygraph Association Newsletter (2002): 20 and 35.

(8) Stanley B. Walters, Principles of Kinesic Interview and Interrogation (Boca Raton, FL: CRC Press, 1996), preface.

(9) Supra note 2.

By William J. Warner, J.D., M.A.
COPYRIGHT 2005 Federal Bureau of Investigation
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Title Annotation:Perspective
Author:Warner, William J.
Publication:The FBI Law Enforcement Bulletin
Geographic Code:1USA
Date:Apr 1, 2005
Previous Article:Violent crime decreases.
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