Following the American Psychological Association’s Guidelines
- Two popular forms of analysis when attempting to assess if an individual is lying include polygraph tests and voice stress assessments. The two tests are similar in nature when concerning their directive and administration, but are gauged rather differently. For example, according to Ken Alder’s, “The Lie Detectors: The History of an American Obsession,” base questions are given prior to the technical polygraph test, wherein the individual is connected to a machine that will monitor heart rate and pulse in an attempt to assess honesty . In comparison, Harry Hollien and associates, authors of, “Issues in Forensic Voice,” outline that voice stress testing is an analysis of the individual’s spoken utterances, distorted speech, and provides a read out of transcripts . Voice stress analysis is also assumed to provide emotions embedded within speech that will allow detective to know which statements are true, and which are false. Psychological stress systems are also implemented throughout the test, meaning the questioner will press the individual more thoroughly if they are suspected of wrongdoing . Typically, with a polygraph test, the questions asked are decided before the individual even arrives . Voice stress analysis allows questioners to change direction and ask questions based on assumed guilt or innocence.
Essentially, both tests are used to determine whether an individual is lying or telling the truth. One does so by monitoring heart rate and blood pressure while the other does so by monitoring speech patterns and stress in one’s voice. However, the polygraph test does appear more fair because the questions are planned beforehand based on the individual’s assumed position in the situation; there are no surprises. Concerning the stress analysis, the examiner is free to ask questions based on if the he or she believes the individual is guilty or innocent. The new questions, or presumed guilt can cause the results to skew and is unfair to the participant.
- The obvious limitations and even weaknesses involved within the voice stress analysis surround the individual based on assumed guilt. According to Aldert Vrij and Par Anders Granhag’s article, “Eliciting Cues to Deception and Truth: What Matters Are the Questions Asked,” scripted questions are essential to an accurate readout in an individual’s voice . Many video clips were viewed in the study and even slight misdirection assuming guilt on the part of the individual, even when innocence was already proven, lead to a higher percentage of stress in the individual’s voice. Therefore, the questions being asked were conclusively leading individuals to become stressful, rather than their own guilt or lack thereof.
While the polygraph test has scripted questions, which allow the individual to understand he or she is not assumed innocent or guilty, this is only a small strength over the voice stress analysis. Stephen E. Fienberg stated in his address, “The Polygraph and Lie Detection,” that too much confidence is placed in polygraph testing as a form of security screening, thus allowing too many security threats to slip through undetected, while “capturing” too many innocent individuals who had never done anything wrong . He also stated that the confidence in polygraph testing runs so deep that it is never questioned which could create dangerous working situations in some cases, primarily because the science behind polygraph testing is so weak. Fienberg stated polygraph evidence has no real basis for accuracy, has never been used as a control on terrorists or spies, and there is little evidence to prove whether experienced examiners understand when individuals taking the test are fooling them. In short, officials trust a test that is rooted almost entirely in hopes and fantasy.
- There are several legal issues regarding both the polygraph test and voice stress testing in regards to whether or not they would be accepted in court. Frank Horvath and associates have already confirmed in their article, published in Journal of Forensic Sciences, that polygraph tests are inadmissible in court due to their unreliability . It is odd that court officials turn polygraph tests away yet they are still considered official and commanding in other professional settings. Voice stress analyses are, according to Hollien, sometimes heard in court, but only as cursory evidence . Judge and jury will hear whether a witness or suspect became panicked or was assumed guilty after being asked a certain question and it is taken into account. However, what is being taken into account far more often during the legal process is what question the individual was asked before and after the proposed evidential question. Aldert Vrij and Par Anders Granhag suggest that voice stress testing is eerily close to council leading the witness on the stand, thus making this form of evidence just as inadmissible as polygraph testing simply because there are no scripted questions; the examiner asks based on assumed guilt . This practice goes against constitutional law to begin with because we all are innocent until proven guilty, and no evidence that defies that should be used against us. Despite that, for the time being, voice stress testing is begrudgingly accepting in court, though it is rarely taken seriously.
References
Alder, K. (2007). The Lie Detectors: The History of an American Obsession. Boston: Free Press.
Fienberg, S. E. (2002). The Polygraph and Lie Detection. The National Academies' National Research Council.
Hollien, H., Huntley Bahr, R., & Harnsberger, J. D. (2014). Issues in Forensic Voice. Journal of Voice, 170-184.
Horvath, F., McCloughan, J., Weatherman, D., & Slowik, S. (2013). The Accuracy of Auditors' and Layered Voice Analysis (LVA) Operators' Judgments of Truth and Deception During Police Questioning. Journal of Forensic Sciences, 385-392.
Vrij, A., & Anders Granhag, P. (2012). Eliciting cues to deception and truth: What matters are the questions asked. Journal of Applied Research in Memory and Cognition, 110-117.
