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Concept: Polygraph


Following the demise of the polygraph, supporters of assisted scientific lie detection tools have enthusiastically appropriated neuroimaging technologies “as the savior of scientifically verifiable lie detection in the courtroom” (Gerard, 2008: 5). These proponents believe the future impact of neuroscience “will be inevitable, dramatic, and will fundamentally alter the way the law does business” (Erickson, 2010: 29); however, such enthusiasm may prove premature. For in nearly every article published by independent researchers in peer reviewed journals, the respective authors acknowledge that fMRI research, processes, and technology are insufficiently developed and understood for gatekeepers to even consider introducing these neuroimaging measures into criminal courts as they stand today for the purpose of determining the veracity of statements made. Regardless of how favorable their analyses of fMRI or its future potential, they all acknowledge the presence of issues yet to be resolved. Even assuming a future where these issues are resolved and an appropriate fMRI lie-detection process is developed, its integration into criminal trials is not assured for the very success of such a future system may necessitate its exclusion from courtrooms on the basis of existing legal and ethical prohibitions. In this piece, aimed for a multidisciplinary readership, we seek to highlight and bring together the multitude of hurdles which would need to be successfully overcome before fMRI can (if ever) be a viable applied lie detection system. We argue that the current status of fMRI studies on lie detection meets neither basic legal nor scientific standards. We identify four general classes of hurdles (scientific, legal and ethical, operational, and social) and provide an overview on the stages and operations involved in fMRI studies, as well as the difficulties of translating these laboratory protocols into a practical criminal justice environment. It is our overall conclusion that fMRI is unlikely to constitute a viable lie detector for criminal courts.

Concepts: Scientific method, Future, Neuroscience, Magnetic resonance imaging, Functional magnetic resonance imaging, Lie, Lie detection, Polygraph


Palmatier and Rovner (2014) discussed the possible interplay of two major methods of polygraph examination, the Comparison Question Test (CQT) and the Concealed Information Test (CIT). In this comment, we argue that such an attempt overlooks fundamental differences between the two methods. Specifically, both methods differ in their criterion variables; detecting deception versus detecting memory traces. This difference can lead to a different evaluation concerning their outcomes within a forensic context. However, Palmatier and Rovner’s (2014) attempt may blur the distinction between the two methods. Furthermore, at least for the present, it is difficult to give a unified explanation of physiological responses in the CQT and CIT based on the preliminary process theory of the orienting response. In sum, Palmatier and Rovner’s (2014) paper may add further confusion to the research and practice of polygraph testing. Additionally, their paper has no relevance to the current practice of Japanese polygraph examination, because Japanese law enforcement uses only the CIT for memory detection in real-life criminal investigations.

Concepts: Present, Physiology, Difference, Differences, Japan, Police, Government of Japan, Polygraph


Palmatier and Rovner (2014) suggested that the Preliminary Process Theory (PPT) is a plausible theoretical account for explaining the rationale underlying two major polygraph tests, the Comparison Question Test (CQT) and the Concealed Information Test (CIT). To support their suggestion they claimed that both tests detect deception while relying on orienting responses. This approach is critically discussed. It was concluded that application of current scientific theories to polygraph diagnostic procedures should be done separately for the CIT and for the CQT. Finally, a call was extended for more research on unanswered questions in polygraph testing.

Concepts: Scientific method, Greek loanwords, Science, Experiment, Philosophy of science, Theory, Theories, Polygraph


This research examined whether a government-initiated pilot project of mandatory polygraph testing would increase the disclosures made by community-supervised sexual offenders in the United Kingdom. The Offender Managers of 332 pilot polygraph sexual offenders and 303 sexual offenders who were receiving usual community supervision were telephoned quarterly, over a 21-month period, to collect information about numbers of clinically relevant disclosures, the seriousness of disclosures made, and actions taken as a result of disclosures. Perceptions of polygraph usefulness were also collected. Offender Managers in the pilot polygraph group-compared to comparison Offender Managers-reported (a) a higher proportion of offenders making at least one disclosure (i.e., 76.5% vs. 51.2% respectively), and (b) that their offenders made more total disclosures overall (Ms = 2.60 vs. 1.25 respectively). The majority of disclosures made by sexual offenders in the polygraph group were associated with the polygraph session itself. Polygraph Offender Managers reported being more likely to take an action that involved increasing supervision, informing a third party, informing Multi-Agency Public Protection Arrangements (MAPPA), changing supervision focus, or issuing a warning to the offender. However, the relative seriousness of disclosures did not appear to differ across groups. In terms of polygraph test results, one third of offenders (most notably those who were higher in risk) failed their first test with “Deception Indicated.” This outcome-received on a first test-was most likely to elicit clinically relevant disclosures. Offender Managers described the polygraph as aiding supervision strategies. This research and its associated caveats are discussed.

Concepts: United Kingdom, Sex offender, Polygraph


Thermoregulatory influences on electrodermal and cardiovascular activity may interfere with the detection of concealed information using a polygraph. This possibility was assessed by means of a mock terrorism scenario. Seventy-two participants were assigned to either a guilty or an innocent role. They were given a polygraph test at one of three ambient temperatures: 10°C, 22°C, or 34°C. Among guilty participants, electrodermal and cardiovascular measures were least effective at 10°C. Electrodermal results were optimal at 22°C, whereas cardiovascular results were optimal at 34°C. Among innocent participants, the effectiveness of these same measures was not affected by ambient temperature. Temperature had no significant impact on respiration results within the guilty or the innocent groups. Taken together, these findings have implications for those who use polygraphs in uncontrolled testing environments.

Concepts: Effect, Effectiveness, Polygraph


This article takes a critical look at the recent Jensen, Shafer, Roby, and Roby study that found that juveniles and adults have no statistically significant different rates of passing sexual history polygraph examinations. Numerous research and statistical issues are identified, including lack of independence, no adjustment for differing rates of opportunity across ages, poor construct validity of deceit, failure to adjust for base rates of deceit in subsequent analyses, and failure to include recidivism as an outcome. In addition, three arguments made by Jensen et al. against using recidivism as an outcome to judge post-conviction polygraph are discussed along with critical assessments of two recent studies examining the relationship between recidivism and sexual history polygraph examinations. It ends with a discussion of the current state of post-conviction polygraph testing research and way forward to find solid, replicable evidence that assesses its utility as a correctional intervention.

Concepts: Scientific method, Critical thinking, Statistics, Statistical significance, Sociology, Psychometrics, Logic, Polygraph


Palmatier and Rovner (2014) made an important attempt to bridge the gap between the accumulated practical experience in field polygraphy, including the increased body of scientific work done by scientists and practitioners within the field and the academic attitude towards Polygraph Testing. They say that the two main polygraph methods, the Concealed Information Test (CIT) and the Comparison Question Test (CQT) though using different protocols, in the end deal with lying and can be explained under the same theoretical concept. They proposed that the Preliminary Process Theory (PPT) developed by Barry R.J. in a totally different context, should be adopted for the construct validity of psychophysiological detection of deception (polygraph). The current commentary argues that even if in the end, the examinee lies (or tells the truth) in both types of test, it does not mean that lying has been measured directly. Instead, the tests represent the efforts to deduce about veracity in the absence of any specific physiological feature representing deception. Moreover; the two methods are not just two different protocols rather; their underlying rationales are different and cannot be reduced to a comprehensive common construct. With regard to PPT, it is pointed out that the explanation of the most important element in CQT, namely, the differential relative significance that truthful and deceptive examinees are expected to attribute to relevant vs. comparison questions, is out of its scope and therefore, unlike the authors' suggestion its place as a cornerstone in the construct validity of polygraph testing is questionable.

Concepts: Scientific method, Truth, Psychometrics, Question, Theory, Lie, Half-truth, Polygraph


Palmatier and Rovner (2014) should be applauded for their efforts to examine whether CQT and CIT polygraph testing methods can be reconciled by common theory. They (understandably) focus on liars in their article, however, liars are only part of the equation. Lie detection tests also involve truth tellers, and the ways in which truth tellers are protected against a false accusation is where the CQT and CIT differ. This important point is not addressed by Palmatier and Rovner (2014), but the concern expressed by CQT opponents that innocent suspects are not well protected in a CQT test needs to be addressed head on by CQT supporters.

Concepts: Truth, Test method, Protection, Software testing, Lie, The Protection of the Mother of God, Lie detection, Polygraph


Despite the empirical and theoretical chasm between the opponents and proponents of polygraphy, its use is prominent among sex offender agencies in the United States. However, current research on polygraph examination outcomes among juvenile sex offenders, along with potential differences from their adult counterparts, is scarce and outdated. In the present study, we assess the difference between juvenile and adult sex offenders in terms of the propensity for passing a sexual history disclosure polygraph examination. A sample of 324 sex offenders (86 juveniles and 238 adults) who engaged in a sexual history disclosure polygraph examination as part of their treatment in an Intermountain West sex offender treatment agency was used for the analysis. Results from preliminary and logistic regression analyses indicate that juvenile and adult offenders do not significantly differ in the likelihood of passing a sexual history disclosure polygraph examination. Implications and limitations are discussed.

Concepts: Scientific method, Regression analysis, Logistic regression, United States, Sex offender, Polygraph, United States v. Scheffer, Cleve Backster


Juvenile sex offenders (JSO) are a specific subset of delinquent adolescents that are receiving more attention because of the crimes they commit and the issues surrounding how to successfully treat their deviant behaviors. Given JSO are such predominant treatment concerns in society, it is essential to identify and target key risk factors. One sexual behavior, bestiality, may be of particular importance to address in treatment. In a meta-analysis conducted by Seto and Lalumiere, a 14% rate of bestiality among JSO was reported. This current study examined the differences in JSO (n = 32) who admitted bestiality based upon a self-report measure, the Multiphasic Sexual Inventory-II (MSI-II), compared to information elicited by polygraphs. The results indicated extensive underreporting of bestiality behaviors between these two sources of information (MSI-II = 37.5%; polygraph = 81.25%). These findings are important given the reliance treatment programs place on information elicited from self-report tools.

Concepts: Psychology, Sexual intercourse, Human sexual behavior, Human sexuality, Human behavior, Juvenile delinquency, Age of consent, Polygraph