Scientific assessment of the accuracy of detection of deception: a reply to Lykken

Psychology and the lie detector industry: A fifty-year perspective

Fifty years ago, in a trenchant analysis that challenged applied lie detection theory and science, David Lykken (1974) brought polygraphic interrogation methods to the attention of academia with the hope that these techniques would come under the purview of psychology and psychophysiology. In this perspective, I examine how this application of psychophysiology has evolved over the last half century and how its status has changed for 1) the comparison (control) question test (CQT), used in forensic applications; 2) polygraph screening tests, used to evaluate examinee integrity; and 3) the concealed information technique (CIT), used to assess recognition memory of crime details. The criticisms of the CQT and screening tests advanced by Lykken have been amplified and focused by the academic community over the last half century. However, this has had little effect on how these methods are practiced and has not curtailed their use. Although most private sector employee screening tests are now prohibited, personnel screening of government employees has increased, and screening tests of sex offenders are now commonplace. Even though the CIT has captured the interest of psychophysiologists as a scientifically defensible technique, its field use is negligible. A primary purpose of polygraphic interrogations continues to be the extraction of admissions and confessions. The lack of change in the polygraph testing status quo stems in large part from unwavering government support for the use of these methods. As a result, polygraph theory and research support continues to rest on shaky ground while practice continues unfettered by valid criticism.

Diagnosing Estimate Distortion Due to Significance Testing in Literature on Detection of Deception

Studies journals typically report or feature results significant by statistical test criterion. This is a bias that prevents obtaining precise estimates of the magnitude of any underlying effect. It is severe with small effect sizes and small numbers of measurements. To illustrate the problem and a diagnosis technique, results of published studies on the detection of deception are graphed. The literature contains large effect sizes affirming that deceptive responses in contrast to truthful responses are associated with more reactive Skin Resistance Responses. These effect sizes when graphed on the x-axis against n on the y-axis are distributed as funnel graphs. A subset of studies show support for predicted small to medium effects on different physiological measures, individual differences, and condition manipulations. These effect sizes graphed by sample ns follow negative correlations, suggesting that effect sizes from published values of t, F, and z are exaggerations.

The 'control' question 'test' (CQT) polygrapher's dilemma: logico-ethical considerations for psychophysiological practitioners and researchers

The so-called 'control' question 'test' (CQT) has been criticized on methodological and ethical grounds by psychophysiologists. The ethical analyses have focussed on the possibility that the CQT's interrogative features may elicit false confessions, but an empirical problem is that the rate of these false confessions is difficult to establish. In this conceptual note, this author raises a logico-ethical problem for the CQT, called the Polygrapher's Dilemma (PD). The two horns of the PD are to damage the innocent examinee classified as deceptive and damage to those examinees' psychological well being who are classified as non-deceptive to the relevant questions and who are not even debriefed concerning their feelings of unease about issues raised by the comparison, so-called 'control' questions. Although there may be arguments about which of the PD's two horns are more serious, there is no doubt that both are, in an absolute sense, ethically negative. Nor is there an ethically justifiable third alternative available. It is also contended that not only practitioners but also researchers (who use the CQT in laboratory, 'mock-crime' situations) are affected by PD. Finally, it is noted that PD exists only for the CQT procedure and not for the more standardized and scientifically based Guilty Knowledge Technique.

The roles of deception, intention to deceive, and motivation to avoid detection in the psychophysiological detection of guilty knowledge

The present study focused on electrodermal differentiation between relevant and neutral items in the Guilty Knowledge paradigm. Three factors were varied in a between-subjects design. The role of deception was examined by varying the type of verbal answer to the questions ("yes," "no," and remaining silent). The intention to deceive factor was examined by contrasting subjects told to delay their answer ("yes" or "no") with those told to produce their answer immediately. Finally, motivation to avoid detection was manipulated by having half the subjects monetarily rewarded for an important (ego relevant) detection task (high motivation), whereas the remaining subjects were neither rewarded nor told that the task was important. The results indicated that a deceptive answer ("no") to the relevant question was associated with an increased differential skin conductance responsivity, but better than chance detection rates were obtained with truthful ("yes") and silent conditions. Equal and significant detection rates were observed when the responses were computed immediately following question presentation, whether the subjects had answered immediately or had delayed their answers. In contrast, differential electrodermal responsivity to the delayed answers was markedly attenuated. The motivation factor had no main or interactive effects on differential responsivity. The present results, together with those obtained in previous studies, suggest that whereas deception is neither a necessary nor a sufficient condition for psychophysiological detection, it may facilitate detection. Possible mechanisms through which such a facilitation could occur were considered.

Evaluating polygraphy from a psychophysiological perspective: a specific-effects analysis

It is suggested that purportedly scientific positions and technologies are actually spiritualistic or superstitious to the extent that specific effects are not identified and evaluated. This claim is then examined with respect to polygraphy, which appears to have particularly strong spiritualistic tendencies. This technology's putative basis is the science of psychophysiology, which is the study of psychological processes by means of unobtrusive physiological measures that reflect functions over which there is relatively little voluntary control. The underlying rationale of polygraphy is that information about these functions provided to the examiner has a specific, beneficial effect of improving the detection of deception. Before considering the validity of the polygraph in these specific-effect terms, the paper notes some serious societal problems involved in the use of the polygraph, problems that suggest that polygraphy is appropriately characterized as a serious "social disease". As to its scientific status, the technique suffers from at least three significant and possibly insurmountable problems: 1) the records are not read "blind"; 2) the method of scoring is subjective, compared to the standards of scientific psychophysiology; and 3) the so-called "control" question method does not involve control in the standard, accepted, scientific sense of that term. However, much of the rest of psychology is also criticised as teleological and spiritualistic, and it is suggested that the polygraph is merely a dramatic illustration of the spiritualist approach that permeates the thought of most researchers in, and practitioners of, the science of psychology.

Electrodermal responsivity to interrogation questions and its relation to self-reported emotional disturbance

The relationship between skin resistance responses (SRRs) and self-reported emotional disturbance was studied in 24 males and 24 females. SRRs to seven interrogation questions were recorded and subjects were requested to rate on visual analogue scales how disturbing they had found each question. The mean within subject correlations were significant for both groups, suggesting that electrodermal responses to interrogation questions are significantly related to the extent to which the subjects find such questions disturbing. A particular question may elicit disturbance for a number of reasons including embarrassment, conflict over how to answer the question, and fear of the consequences of possible detection.