Polygraph Testimony and Juror Judgments: A Comparison of the Guilty Knowledge Test and the Control Question Test1

The present experiment investigated the impact of the Control Question Test (CQT) and the Guilty Knowledge Test (GKT) on the verdicts of mock jurors. Although studies have indicated that polygraph evidence has little influence on jurors' verdicts (Cavoukian & Heselgrave, 1980; Spanos, Myers, Dubreuil, & Pawlak, 1992–1993), no research has previously distinguished between the different types of polygraph tests and their impact on juror verdicts. In the present study, jurors were shown a videotape of a simulated rape-murder trial that contained either CQT polygraph evidence, GKT polygraph evidence, or no polygraph evidence. No differences were found among the 3 conditions for either jury verdicts or individual juror verdicts, and jurors tended to rate both forms of polygraph testimony below other forms of equally suspect evidence, such as eyewitness testimony, in its influence on their decision-making process.     

Gender effects on individual verdicts and on mock jury verdicts in a Simulated Acquaintance Rape Trial

Since more women than men college students vote guilty in a simulated acquaintance rape trial [e.g., G. J. Fischer (1991) “Cognitive predictors of not-guilty verdicts in a Simulated Acquaintance Rape Trial,”Psychological Reports, Vol. 68, pp. 1199–1206], guilty mock jury verdicts were expected to increase as a function of the number of women on the jury (i.e., 0, 2, 4, 6, 8, 10, and 12). However, guilty verdicts did not increase significantly until either females were an overwhelming majority (i.e., 10 women to 2 men) or the jury was all female. Even in the latter conditions, guilty verdicts were fewer than would be expected based on the 86% of women and 66% of men voting guilty on a survey completed after reading about the trial, but before serving on a jury. Although a very large majority of females were needed to increase guilty verdicts, a majority appeared to lessen the likelihood of not guilty verdicts. For example, when a majority of jurors were female, 0/18 hung juries leaned toward a not guilty verdict vs. 11/34 juries leaning toward a not guilty verdict when less than or equal to one half of the jurors were female. Most of the students were White (85%), with 4% Asian, 3.2% Black, 3.2% Hispanic, and 4% “Other.”     

Enhancing the credibility of complainants in child sexual assault trials: the effect of expert evidence and judicial directions

This study investigated the knowledge and misconceptions of jury‐eligible citizens about children's reliability as witnesses and responses to child sexual assault (CSA), and examined the influence of expert evidence and judicial directions in challenging common misconceptions. Community volunteers (N = 130) read one of five versions of a simulated jury trial, and completed a pre‐ and post‐trial questionnaire to provide measures of their knowledge of children's responses to sexual abuse, perceptions of victim credibility, and verdict. Results revealed that endorsement of CSA misconceptions negatively impacted ratings of complainant credibility and verdicts. Judicial directions provided before the child complainant testified enhanced complainant credibility, which in turn predicted guilty verdicts. Comparisons of the effectiveness of two procedural legal mechanisms to manage juror misconceptions and improve knowledge about CSA provide guidance for future researchers investigating ways to increase fairness in cases of CSA. Copyright © 2010 John Wiley & Sons, Ltd.     

New perspectives in assessing deception: The evolution of the truth machine

In recent years a growing interest has arisen in the development of tools for the detection of deception. Since William M. Marston's first publication (1917) on the use of the polygraph as a lie detector, the application of this tool, commonly known as the truth machine, has evolved. Modern technologies are now trying to push the issue further, investigating brain activity during deception using functional Magnetic Resonance Imaging (fMRI). The aim of this paper is to summarise the evolution of research from the original use of the polygraph to the use of new technologies in detecting deception, in order to provide an overview of the recent developments on the use of measurements of deception, and promote new research in this highly important domain of applied cognitive psychology.     

Sensitizing Potential Jurors to Variations in Eyewitness Evidence Quality Using Counterfactual Thinking

Jurors often have difficulty evaluating eyewitness testimony. Counterfactual thinking is a type of mental simulation that informs causal inference. Encouraging jurors to think counterfactually about eyewitness factors may sensitize them to these factors' causal influence on eyewitness identification and testimony accuracy, improving their overall judgments (such as verdicts). One hundred twenty‐one undergraduate participants were randomly assigned to read a scenario containing either high‐quality or low‐quality eyewitness evidence and to evaluate eyewitness factors adopting either their default or a counterfactual mindset via a question‐order manipulation. Logistic regressions and analyses of variance revealed that a counterfactual mindset lowered perceptions of eyewitness accuracy and guilty verdicts (compared with the default mindset) when the evidence was poor; a counterfactual mindset, however, did not increase perceptions of accuracy and guilty verdicts when evidence was strong. We discuss possible mechanisms underlying these effects and identify several potential avenues for future research.Copyright © 2016 John Wiley & Sons, Ltd.     

Effects of pre‐trial publicity and jury deliberation on juror bias and source memory errors

We examined the effects of exposure to pre‐trial publicity (PTP) and jury deliberation on juror memory and decision making. Mock jurors either read news articles containing negative PTP or articles unrelated to the trial. They later viewed a videotaped murder trial, after which they either made collaborative group decisions about guilt or individual decisions. Finally, all participants independently attributed specific information as having been presented during the trial or in the news articles. Exposure to PTP significantly affected guilty verdicts, sentence length, perceptions of defendant credibility, and misattributions of PTP as having been presented as trial evidence. Jury deliberation had significant effects on jury verdicts, perceptions of defendant credibility, source memory for trial items, and confidence in source memory judgements, but did not affect sentences or critical source memory errors. Copyright © 2006 John Wiley & Sons, Ltd.     

Information Processing in Joined and Severed Trials

The present study was conducted to determine the process by which jurors reach verdicts in trials in which multiple charges are joined in one indictment. The experiment was designed to test the impact of joinder of affenses, similarity of offenses, and evidentiary strength of jurors' ability to process trial evidence. The results gathered from 220 male and female subjects indicated, as previous research has shown, that joined trials lead to more guilty verdicts than severed trials; that the first charge in a joined trial accounts for this "joinder effect," receiving significantly more guilty verdicts than its severed counterpart. When joined trials are composed of similar categories of crimes, guilt verdicts increase and jurors tend to confuse evidence-as shown by a high rate of antidefendant intrusions from case two to case one. More antidefendant cognitions were also found when the cases were similar. Furthermore, case similarity interacted with the evidentiary strength of the charges in joined trials.     

Negative and positive pretrial publicity affect juror memory and decision making

The experiment examined the effects of exposure to pretrial publicity (PTP) and delay on juror memory and decision-making. Mock jurors read news articles containing negative PTP, positive PTP, or unrelated articles. Five days later, they viewed a videotaped murder trial, after which they made decisions about guilt. Finally, all participants independently attributed specific information as having been presented during the trial or in the news articles. Half of the jurors rendered their verdicts and completed the source-memory test immediately after the trial, while the other half did so after a 2-day delay. Exposure to PTP significantly affected guilty verdicts, perceptions of defendant credibility, juror ratings of the prosecuting and defense attorneys, and misattributions of PTP as having been presented as trial evidence. Similar effects were obtained for negative and positive PTP. Delay significantly increased source-memory errors but did not influence guilt ratings. Defendant's credibility and juror ratings of prosecuting and defense attorneys significantly mediated the effect of PTP on guilt ratings. (PsycINFO Database Record (c) 2008 APA, all rights reserved).     

The Impact of the Guilty but Mentally III Verdict on Juror Decisions: An Empirical Analysis

The present study attempted to determine the impact of alternative verdict choices on the decisions of mock jurors. Subjects used in this study as mock jurors were all college undergraduates. They were shown one of two versions of a videotaped simulated murder trial. Both films presented a defendant who appeared to be suffering emotional difficulties, but in one film the defendant had clearly committed the act while in the other film the defendant's actions were less certain. Subjects than gave their individual verdicts and, after deliberation with other subjects, a total jury verdict. The verdicts available to the subjects varied across three conditions such that the subjects in one condition were only allowed to find the defendant to be innocent or guilty. In another condition the subjects could find the defendant innocent, guilty or not guilty by reason of insanity (NGRI). In the third condition the subjects were allowed to choose between innocent, guilty, NGRI, and guilty but mentally ill (GBMI). The results indicated that the addition of the "mental health" verdicts had a significant impact on the decisions of the jurors. In particular, it appears that only defendants who would otherwise have been found innocent were likely to be found NGRI. This study also indicated that the GBMI verdict is very attractive to mock jurors. Indeed, even innocent defendants were found to be GBMI, a form of guilt, when this alternative was made available. These findings raise potentially important constitutional and practical issues for the trial of emotionally disturbed criminal defendants.     

Jurors' Decisions in Trials of Battered Women Who Kill: The Role of Prior Beliefs and Expert Testimony1

The present research explored the influence of four factors on mock jurors' decisions in a homicide trial involving a battered woman who killed her abusive husband: (a) jurors' preexisting beliefs about wife abuse, (b) the presence of expert testimony on the battered woman syndrome, (c) jurors' beliefs in a just world, and (d) gender. Mock jurors listened to a trial involving a woman who had killed her abuser, which either contained expert testimony or did not, and then rendered various judgments about the case. Results indicated that those individuals who were more informed about the dynamics of abuse and those exposed to the expert testimony, compared to their respective counterparts, were more believing of the battered woman's account of what occurred. In general, weak believers in a just world were more lenient in their judgments, with verdicts of not guilty being associated with weaker beliefs in a just world than guilty verdicts. Weak believers in a just world also felt that the expert testimony applied more to the defendant than did strong believers. Finally, women who were weak believers in a just world were less likely to hold the defendant responsible for the events and to be more informed about the dynamics of abuse following the experiment.     

The Effects of Bifurcation and Death Qualification on Assignment of Penalty in Capital Crimes1

An experiment was conducted to test the effects of the bifurcated trial procedure and the death qualification process on sentencing and verdicts in death penalty cases. Forty-four 12-person juries, assigned to one of five trial conditions, returned verdicts indicating that death qualified, bifurcated juries gave the most severe verdicts and the highest proportion of guilty verdicts, while non-death qualified, trial only, juries returned the least severe verdicts and the highest proportion of not guilty or hung outcomes. Thirty-seven penalty phase juries, of which 20 had previously assigned guilt, were distributed among five penalty conditions. The sentencing data revealed that the most severe sentences were given by the death qualified, bifurcated juries. The least severe sentences were returned by the non-death qualified, bifurcated juries. Juries impaneled for the penalty phase only and death qualified meted out moderate sentences.     

The Effect of Electrophysiological Neuroscientific Deception Detection Evidence on Juror Judgments in a Criminal Trial

There are concerns that if neuroscientific deception detection evidence becomes admissible in court, jurors may weigh it inappropriately. We investigated whether mock jurors were influenced more by electrophysiological than behavioral evidence that a defendant in a criminal trial was lying. Participants’ perceptions of evidence quality predicted verdict choice, and quality ratings were higher for neuroscientific than for behavioral evidence. However, both types of evidence increased guilty verdicts similarly, and the inclusion of neuroimages had no additional impact. These findings suggest that neuroscientific evidence may be processed differently than other types of deception evidence, but it is not necessarily more persuasive.     

Does the Onset Controllability of Diagnostic Labels Affect the Perceived Appropriateness of an Insanity Verdict?1

The present study attempted to look at reactions to an insanity verdict by asking participants to rate the appropriateness of an insanity verdict already handed down by a jury. A sample of 196 adults read a short vignette describing the defendant's crime, a courtappointed psychiatrist's diagnosis, and a jury's verdict (guilty; or not guilty by reason of insanity, NGRI). Using Weiner's (1995) responsibility model, it was predicted and found that an insanity verdict was deemed less appropriate when the defendant was construed to have an onset controllable disorder. Path analyses indicate that onset controllability, responsibility judgments, and affective reactions do not account for the perceived appropriateness of guilty and NGRI verdicts in the same way.     

Reactions of Participants and Observers to Modes of Adjudication1

An important aspect of conflict resolution by judgment of a third party is the extent to which participants and observers are satisfied that both the procedure and the outcome are fair and impartial. Male undergraduates participated in a business simulation, which resulted in a controversy placing them in the position of defendants in a trial. An examination was then made of the effects of adversary and nonadversary procedures, prior belief about guilt, and favorableness of the judgment on participant subjects’perceptions of the adjudication. Another group of subjects who had no prior information about the guilt or innocence of the defendent served as observers. Participant subjects viewed the adversary procedure as most fair and satisfying. They were also most satisfied with judgments resulting from the adversary procedure, independently of pretrial belief or favorableness of verdict. Participants also preferred innocent to guilty verdicts, regardless of their pretrial belief. Subjects who held a pretrial belief of innocence were particularly dissatisfied with guilty verdicts and with the nonadversary trial procedure. Observers also found the adversary procedure to be most fair, and expressed a preference for innocent verdicts.     

The Influence of Eyewitness Nonidentifications on Mock-Jurors' Judgments of a Court Case1

Two experiments examined the effect of an eyewitness nonidentificution on mock-jurors' verdicts in robbery cases, as well as the effects of number of identifying eyewitnesses and status of the identifying witness (victim or bystander). Subjects read court case summaries that included variable eyewitness evidence and constant alibi, circumstantial, and character evidence. In Experiment 1, frequency of guilty verdicts was significantly less when an eyewitness testified in court that the defendant was not the perpetrator, even when this nonidentification opposed two positive identifications. In Experiment 2, a low guilty rate was again associated with the presence of a nonidentifier, but only when the nonidentifier actually testified in court and stipulated that the defendant is “not the man.” On the average, 70% of the jurors delivered guilty verdicts when both the victim and bystander gave identifying testimony, whereas 12.5% delivered guilty verdicts when the bystander gave opposing nonidentifying testimony. Guilty rates were unaffected by the identifying eyewitness' status and (in Experiment 2, but not Experiment 1) were higher when there were two (vs. one) identifying eyewitnesses.     

A Review of the Office of Technology Assessment Report on Polygraph Validity

This article reviews the assessment of polygraphic lie detection produced by the Office of Technology Assessment (OTA) in November 1983. The review argues that use of the lambda statistic to summarize polygraph accuracy in the OTA report was inappropriate because the studies examined differ widely in base rates of guilt and innocence. Using Lykken's (1981) average accuracy statistic and avoiding overlapping data sets found in the OTA report, the review finds that field studies, analog studies, and guilty knowledge studies produce very similar average accuracy (82% to 88%). Guilty knowledge tests tend to be biased toward false negatives, whereas control question tests tend to be biased toward false positives. The striking similarity of results for field and analog studies using control question tests contradicts the common belief that results of analog testing are weak and not generalizable to field practice. It is argued that analog studies are in fact the only hope for improving the validity of polygraph testing.     

Lying about facial recognition: an fMRI study

Novel deception detection techniques have been in creation for centuries. Functional magnetic resonance imaging (fMRI) is a neuroscience technology that non-invasively measures brain activity associated with behavior and cognition. A number of investigators have explored the utilization and efficiency of fMRI in deception detection. In this study, 18 subjects were instructed during an fMRI "line-up" task to either conceal (lie) or reveal (truth) the identities of individuals seen in study sets in order to determine the neural correlates of intentionally misidentifying previously known faces (lying about recognition). A repeated measures ANOVA (lie vs. truth and familiar vs. unfamiliar) and two paired t-tests (familiar vs. unfamiliar and familiar lie vs. familiar truth) revealed areas of activation associated with deception in the right MGF, red nucleus, IFG, SMG, SFG (with ACC), DLPFC, and bilateral precuneus. The areas activated in the present study may be involved in the suppression of truth, working and visuospatial memories, and imagery when providing misleading (deceptive) responses to facial identification prompts in the form of a "line-up".