Understanding Pretrial Publicity: Predecisional Distortion of Evidence by Mock Jurors.

Prejudicial pretrial publicity (PTP) constitutes a serious source of juror bias. The current study examined differences in predecisional distortion for mock jurors exposed to negative PTP (N-PTP) versus nonexposed control participants. According to work by K. A. Carlson and J. E. Russo (2001), predecisional distortion occurs when jurors bias new evidence in favor of their current leading party (prosecution or defense) rather than evaluating this information for its actual probative properties. Jury-eligible university students (N=116) acted as jurors in a mock trial. Elevated rates of guilty verdicts were observed in the N-PTP condition. Predecisional distortion scores were significantly higher in the N-PTP condition and reflected a proprosecution bias. The effect of prejudicial PTP on verdict outcomes was mediated by predecisional distortion in the evaluation of testimony. Results are discussed in relation to motivated decision making and confirmation biases. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social inference processes in juror judgments of multiple-offense trials.

According to law, a defendant may be tried for multiple offenses in a single trial, although the courts intuitively recognize that such "joinder" may be prejudicial. The present study investigated the effects of joinder on jurors' decisions, emphasizing the social psychological mechanisms underlying judgmental biases. 732 representative jurors (aged 18–82 yrs) judged a videotaped trial of a single offense or a joined trial of 3 offenses that varied as a function of (a) charge similarity, (b) evidence similarity, and (c) judges' instructions designed to reduce judgment biases. A defendant was more likely to be convicted on a particular charge in a joined trial than on the same charge tried alone, and judges' instructions were ineffective. Joinder produced confusion of evidence and negative inferences about the defendant, but did not significantly influence perceptions of evidence strength. Defendant and evidence ratings were strongly related to verdicts, whereas confusion was not. Results suggest that the effects of joinder are mediated through inferences about the defendent's criminality. (64 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conviction proneness and the authoritarian juror: Inability to disregard information or attitudinal bias?

In Exp I, 120 undergraduate mock jurors completed the Mitchell-Byrne Authoritarianism Scale and rendered verdicts and gave probability of guilt estimates for trial evidence involving 2 levels of admissibility of wiretap evidence (inadmissible and admissible) and 2 levels of incrimination value of wiretap evidence (exonerating and incriminating). Results support a pro- and antidefendant bias rather than a differential cognitive ability model. Exp II, involving 160 undergraduates, determined whether repeating and emphasizing judge's instructions to jurors to disregard inadmissible evidence would reduce authoritarians' tendency to incorporate it. Authoritarian Ss were more likely to convict, especially in the presence of incriminating evidence, regardless of its admissibility and judge's emphasis. The 2 studies suggest that authoritarians are characterized by an antidefendant bias that influences their responses to trial evidence and that is not easily overcome by emphasizing the judge's instructions. (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Beware of samples! A cognitive-ecological sampling approach to judgment biases.

A cognitive-ecological approach to judgment biases is presented and substantiated by recent empirical evidence. Latent properties of the environment are not amenable to direct assessment but have to be inferred from empirical samples that provide the interface between cognition and the environment. The sampling process may draw on the external world or on internal memories. For systematic reasons (proximity, salience, and focus of attention), the resulting samples tend to be biased (selective, skewed, or conditional on information search strategies). Because people lack the metacognitive ability to understand and control for sampling constraints (predictor sampling, criterion sampling, selective-outcome sampling, etc.), the sampling biases carry over to subsequent judgments. Within this framework, alternative accounts are offered for a number of judgment biases, such as base-rate neglect, confirmation bias, illusory correlation, pseudocontingency, Simpson's paradox, outgroup devaluation, and pragmatic-confusion effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Nominal and interactive groups: Effects of preinstruction and deliberations on deicisions and evidence recall in complex trials.

Two studies assessed the effects of preinstruction on decision making in simulated civil trials. In Study 1, substantive instructions were presented before the evidence, after the evidence, before and after the evidence, or not at all to nominal jurors who did not deliberate and to interactive jurors who did deliberate. Preinstructed nominal jurors differentiated among the plaintiffs in awarding damages, whereas postinstructed nominal and interactive jurors did not. Group discussion and preinstruction augmented damage awards and improved recall of evidence only for preinstructed jurors. Study 2 suggested that substantive preinstruction engaged a proplaintiff bias when trial evidence was technically difficult but enhanced systematic processing when the evidence was presented in less complex language. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

How effective are the cross-examination and expert testimony safeguards? Jurors' perceptions of the suggestiveness and fairness of biased lineup procedures.

Mock jurors (N = 800) viewed a videotaped trial that included information about a lineup identification procedure. Suggestiveness of the eyewitness identification procedure varied in terms of foil, instruction, and presentation biases. Expert testimony regarding the factors that influence lineup suggestiveness was also manipulated. Criteria included juror ratings of lineup suggestiveness and fairness, ratings of defendant culpability, and verdicts. Jurors were sensitive to foil bias but only minimally sensitive to instruction and presentation biases. Expert testimony enhanced juror sensitivity only to instruction bias. These results have implications for the effectiveness of cross-examination and expert testimony as safeguards against erroneous convictions resulting from mistaken identifications. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Inadmissible evidence and juror verdicts.

288 mock jurors watched videotapes of a realistic simulated trial and rendered verdicts as individuals before deliberation and as groups after deliberation. In a 3?×?2 design, the trial evidence and judge's instructions were varied. The trial contained inadmissible evidence supporting conviction, inadmissible evidence supporting acquittal, or no inadmissible evidence. The judge's instructions emphasized the importance either of protecting the defendant's due process rights or of reaching an accurate verdict. Jurors who received proacquittal inadmissible evidence were less likely to convict than those who received either proconviction inadmissible evidence or no inadmissible evidence. The conviction rates in the latter 2 conditions did not differ significantly. The variation in judge's instructions had no effect. Paradoxically, jurors who received proconviction inadmissible evidence thought that their verdicts had been influenced by it, whereas those who received proacquittal inadmissible evidence thought that their verdicts has not been influenced by it. Jurors' evaluations of the strength of admissible evidence were not influenced by the presence of inadmissible evidence. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Juror competence in civil trials: Effects of preinstruction and evidence technicality.

48 jury-eligible adults heard 1 of 4 versions of a tort trial. The design combined high and moderate levels of evidence technicality and the placement of substantive judicial instructions either before or after evidence presentation. Jurors given instructions before hearing the evidence for liability and before the evidence for compensation made clear distinctions among 4 differentially worthy plaintiffs, whereas jurors instructed after evidence presentation were not able to distinguish among the plaintiffs. Preinstructions enabled jurors to devise a causal model, as measured by both verbal representation of the evidence and recognition tests, that contained more probative evidence and less nonprobative and evaluative information than the models constructed by jurors who were postinstructed. Preinstructed jurors were better able than postinstructed jurors to correctly reject recognition items not part of the trial text and to correctly identify items from the trial. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive mediation of inconsistency discounting.

Conducted 2 experiments to examine the effects of inconsistency and credibility information in a complex, multiple source, multiple communication criminal trial setting. The source of the inconsistent testimony was low in credibility. The testimony structure was manipulated such that association of the sources with the content of their testimony was facilitated (high person focus) or disrupted (low person focus). Ss participated as mock jurors who read testimony, rendered verdicts, and attempted to recall the testimony. Exp I, conducted with 96 paid Ss, demonstrated that discounting of inconsistent testimony was likely under conditions of high but not low person focus. Exp II, conducted with 48 undergraduates, examined the relation between jurors' spontaneous cognitive reactions at encoding and the jurors' verdicts. Only high person focus jurors discounted the inconsistent testimony at encoding. Results suggest that discounting occurs in the context of jurors generating an integrated cognitive representation of the trial events that is a function of both the actual testimony items and jurors' own spontaneous inferences. Several other information-processing consequences, such as the organization of recall and memory for consistent and inconsistent testimony items, were also examined. These data are considered in terms of their implications for recent cognitive elaboration models and models of juror decision making. (50 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Considering the opposite: A corrective strategy for social judgment.

Proposes that several biases in social judgment result from a failure to consider possibilities at odds with beliefs and perceptions of the moment. Individuals who are induced to consider the opposite position, therefore, should display less bias in social judgment. In 2 experiments, with 150 undergraduates, this reasoning was applied to 2 domains—biased assimilation of new evidence on social issues and biased hypothesis testing of personality impressions. Ss were induced to consider the opposite through explicit instructions to do so and through stimulus materials that made opposite possibilities more salient. In both experiments, the induction of a consider-the-opposite strategy had greater corrective effect than more demand-laden alternative instructions to be as fair and unbiased as possible. Results are consistent with previous research on perseverance, hindsight, and logical problem solving, and they suggest an effective method of retraining social judgment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An associative framework for probability judgement: An application to biases.

Three experiments show that understanding of biases in probability judgment can be improved by extending the application of the associative-learning framework. In Experiment 1, the authors used M. A. Gluck and G. H. Bower's (1988) diagnostic-learning task to replicate apparent base-rate neglect and to induce the conjunction fallacy in a later judgment phase as a by-product of the conversion bias. In Experiment 2, the authors found stronger evidence of the conversion bias with the same learning task. In Experiment 3, the authors changed the diagnostic-learning task to induce some conjunction fallacies that were not based on the conversion bias. The authors show that the conjunction fallacies obtained in Experiment 3 can be explained by adding an averaging component to M. A. Gluck and G. H. Bower's model. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The utility of theories in intuitive statistics: The robustness of theory-based judgments.

Research on human judgment demonstrates that people's theories often bias their evaluation of evidence and suggests that people might be more accurate if they were unbiased by prior beliefs. In 2 studies using the covariation estimation problem and the t-test problem, judgments made by Ss who had potentially biasing prior information about data were compared to those made by Ss who were not biased by prior information. 265 undergraduates served as Ss in Study 1; 201 undergraduates were Ss in Study 2. The quality of the data was varied to present Ss with data that were either well-behaved or contaminated with outliers. In both studies, Ss' judgments approximated robust statistical measures rather than the conventional measures typically used as normative criteria. The usual biasing effects of prior beliefs were found, along with an advantage for Ss who had prior theories—even incorrect ones—over Ss who were completely "objective." Potentially biasing beliefs both enhanced Ss' sensitivity to the bulk of the data and reduced the influence atypical scores had on their estimates. Evidence is provided that this robustness results from the fact that prior theories make judgment problems more meaningful. (40 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of complexity on jurors' verdicts and construction of evidence.

One hundred twenty mock jurors heard 1 of several versions of a civil trial. The tort trial was either high or low in information load and contained evidence that either clearly favored the plaintiffs or was ambiguous. Expert witnesses testified in either technical or less technical language. Verdicts favored the plaintiffs when the evidence was clear and was presented in technical language because technical language enhanced witnesses' credibility when the evidence was clear. Although high information loads and technical language hindered evidence processing, jurors endeavored to comprehend, as indicated by the recall of more facts and alternative constructions of the evidence when that evidence was ambiguous. However, those constructions were of poorer quality, incorporating evidence of lesser probative value. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Understanding the limits of limiting instructions: Social psychological explanations for the failures of instructions to disregard pretrial publicity and other inadmissible evidence.

Inadmissible information may come in a variety of forms including pretrial publicity and in-court statements made by witnesses or attorneys. A number of remedies have been proposed for controlling the damaging effects of such evidence. When inadmissible information comes in the form of pretrial publicity, judges may issue a continuance or rely on voir dire to remove biased jurors. In addition, it has been argued that deliberations may serve as an effective remedy. Finally, judges may issue an admonition to disregard pretrial publicity or other inadmissible evidence presented in court. Empirical research has demonstrated that such safeguards are relatively ineffective and sometimes produce a backfire effect, resulting in jurors being more likely to rely on inadmissible information after they have been specifically instructed to disregard it. Several social psychological theories provide explanations for the failures of admonitions, including belief perseverance, the hindsight bias, reactance theory, and the theory of ironic processes of mental control. Existing inadmissible evidence research and relevant social psychological theories are reviewed. The article concludes with a discussion of theoretically based policy recommendations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Describing jurors' personal conceptions of insanity and their relationship to case judgments.

In a series of studies, prototype theory was applied to describe the nature, variability, and effect of jurors' conceptions of insanity. Specifically, (a) 80 jurors described the features of their prototypes of insanity, (b) 5 jurors combined similar features to develop a core set of features to measure individual differences, and (c) 135 jurors and 236 undergraduates completed measures of individual differences in prototypes and attitudes toward the insanity defense and the criminal justice system and rendered insanity case judgments. Results suggest that (a) jurors' prototypes of insanity cannot be reduced to legal or psychiatric constructs; (b) although there are marked individual differences in prototypes, there are 3 identifiable groups of jurors with prototypes that emphasize severe mental disability, "moral insanity," and mental state at the time of the offense; and (c) these prototypes are associated with case-relevant attitudes and affect the way in which jurors interpret case information and render verdicts. Implications for future research, legal reform, and the presentation of expert evidence are analyzed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Motives for social comparison: The construction–validation distinction.

Suggests that informational social comparison can be motivated by 2 concerns: (a) an interest in obtaining from others any information about the entity that they have at their disposal and that the individual lacks or (b) an interest in obtaining information about the validity of one's judgment by determining if that judgment derives from one's personal biases or from the qualities of the entity. A comparison act motivated by the former concern is termed construction and by the latter is termed validation. The results of Exp I with 38 undergraduates suggest that a construction process occurs only when one's perceived level of information is low and others might possess additional information about the object. Two additional experiments with 39 undergraduates examined the impact of agreement and disagreement from sources similar or dissimilar on a relevant attribute. Exp II examined whether the judgments of each of these others are attributed largely to the other's similarity/dissimilarity or to the amount of information about the entity that the other is thought to possess. Exp III examined the implications of the attributional patterns obtained in Exp II for choice of comparison other under motives to construct vs validate. The 2 motives were found to lead to differing preferences regarding choice of comparison other. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Some more sensitive measures of sensitivity and response bias.

In this article, the author proposes a new pair of sensitivity and response bias indices and compares them to other measures currently available, including d′ and β of signal detection theory. Unlike d′ and β, these new performance measures do not depend on specific distributional assumptions or assumptions about the transformation from stimulus information to a discrimination judgment. With simulated and empirical data, the new sensitivity index is shown to be more accurate than d′ and 16 other indices when these measures are used to compare the sensitivity levels of 2 experimental conditions. Results from a perceptual discrimination experiment demonstrate the feasibility of the new distribution-free bias index and suggest that biases of the type defined within the signal detection theory framework (i.e., the placement of a decision criterion) do not exist, even under an asymmetric payoff manipulation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Egocentric biases in availability and attribution.

Conducted 5 experiments to assess biases in availability of information in memory and attributions of responsibility for the actions and decisions that occurred during a previous group interaction. The S populations sampled included naturally occurring discussion groups (of undergraduates), 37 married couples, 74 female and 84 male players on intercollegiate basketball teams, and groups of undergraduates assembled in the laboratory. Data provide consistent evidence for egocentric biases in availability and attribution: The S's own contributions to a joint product were more readily available, i.e., more frequently and easily recalled, and Ss accepted more responsibility for a group product than other participants attributed to them. In addition, statements attributed to the self were recalled more accurately and the availability bias was attenuated, though not eliminated, when the group product was negatively evaluated. When another S's contributions were made more available to the S via a selective retrieval process, this S allocated correspondingly more responsibility for the group decisions to the coparticipant. The determinants and pervasiveness of the egocentric biases are considered. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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) 2010 APA, all rights reserved)