Social cognitive processes explain bias in juror decisions.

Jury decisions are among the most consequential social decisions in which bias plays a notable role. While courts take measures to reduce the influence of non-evidentiary factors, jurors may still incorporate biases into their decisions. One common bias, crime-type bias, is the extent to which the perceived strength of a prosecutor's case depends on the severity of the crime. Moral judgment, affect and social cognition have been proposed as core processes underlying this and other biases. Behavioral evidence alone has been insufficient to distinguish these explanations. To identify the mechanism underlying crime-type bias, we collected functional magnetic resonance imaging patterns of brain activation from mock jurors reading criminal scenarios. Brain patterns from crime-type bias were most similar to those associated with social cognition (mentalizing and racial bias) but not affect or moral judgment. Our results support a central role for social cognition in juror decisions and suggest that crime-type bias and cultural bias may arise from similar mechanisms.

Neural Support for Contributions of Utility and Narrative Processing of Evidence in Juror Decision Making.

Efforts to explain complex human decisions have focused on competing theories emphasizing utility and narrative mechanisms. These are difficult to distinguish using behavior alone. Both narrative and utility theories have been proposed to explain juror decisions, which are among the most consequential complex decisions made in a modern society. Here, we asked jury-eligible male and female subjects to rate the strength of a series of criminal cases while recording the resulting patterns of brain activation. We compared patterns of brain activation associated with evidence accumulation to patterns of brain activation derived from a large neuroimaging database to look for signatures of the cognitive processes associated with different models of juror decision-making. Evidence accumulation correlated with multiple narrative processes, including reading and recall. Of the cognitive processes traditionally viewed as components of utility, activation patterns associated with uncertainty, but not value, were more active with stronger evidence. Independent of utility and narrative, activations linked to reasoning and relational logic also correlated with increasing evidence. Hierarchical modeling of cognitive processes associated with evidence accumulation supported a more prominent role for narrative in weighing evidence in complex decisions. However, utility processes were also associated with evidence accumulation. These complementary findings support an emerging view that integrates utility and narrative processes in complex decisions.SIGNIFICANCE STATEMENT The last decade has seen a sharply increased interest in narrative as a central cognitive process in human decision-making and as an important factor in the evolution of human societies. However, the roles of narrative versus utility models of decision-making remain hotly debated. While available models frequently produce similar behavioral predictions, they rely on different cognitive processes and so their roles can be separated using the right neural tests. Here, we use brain imaging during mock juror decisions to show that cognitive processes associated with narrative, and to a lesser extent utility, were engaged while subjects evaluated evidence. These results are consistent with interactions between narrative and utility processes during complex decision-making.

Modelling the effects of crime type and evidence on judgments about guilt.

Concerns over wrongful convictions have spurred an increased focus on understanding criminal justice decision-making. This study describes an experimental approach that complements conventional mock-juror experiments and case studies by providing a rapid, high-throughput screen for identifying preconceptions and biases that can influence how jurors and lawyers evaluate evidence in criminal cases. The approach combines an experimental decision task derived from marketing research with statistical modeling to explore how subjects evaluate the strength of the case against a defendant. The results show that, in the absence of explicit information about potential error rates or objective reliability, subjects tend to overweight widely used types of forensic evidence, but give much less weight than expected to a defendant's criminal history. Notably, for mock jurors, the type of crime also biases their confidence in guilt independent of the evidence. This bias is positively correlated with the seriousness of the crime. For practicing prosecutors and other lawyers, the crime-type bias is much smaller, yet still correlates with the seriousness of the crime.

Juries and medical malpractice claims: empirical facts versus myths.

Juries in medical malpractice trials are viewed as incompetent, antidoctor, irresponsible in awarding damages to patients, and casting a threatening shadow over the settlement process. Several decades of systematic empirical research yields little support for these claims. This article summarizes those findings. Doctors win about three cases of four that go to trial. Juries are skeptical about inflated claims. Jury verdicts on negligence are roughly similar to assessments made by medical experts and judges. Damage awards tend to correlate positively with the severity of injury. There are defensible reasons for large damage awards. Moreover, the largest awards are typically settled for much less than the verdicts.

Expert evidence, the adversary system, and the jury.

Many assertions have been made about the competence of juries in dealing with expert evidence. I review the types of expert evidence that jurors hear and the impact of adversary legal procedure on the form and manner in which evidence is presented. Empirical research indicates that jurors understand the adversary process, that they do not automatically defer to the opinions of experts, and that their verdicts appear to be generally consistent with external criteria of performance. Conflicts between the American adversary system and changes in trial procedures that might assist the jury in its task are also considered here.

Case studies of pre- and midtrial prejudice in criminal and civil litigation.

This paper presents a number of case studies involving pre- and midtrial prejudice in criminal and civil litigation. The cases reveal deficiencies in the way that prejudicial publicity has been conceptualized and operationalized in many simulation experiments. The studies reveal that potential juror prejudices that concern lawyers and judges involve more than just main effects of mass media. Pre- and midtrial prejudice also involves more general prejudices, gossip and rumor, the assertion of community normative values about justice, and conformity pressures. Four categories of prejudice recognized in American law are described and labeled: interest, specific, generic, and conformity prejudice. The case studies also reveal interesting dynamics involving "minimization" and inconsistency in jurors' self-reports of attitudes which contradict a commonly held judicial view that superficial questioning is sufficient to uncover prejudice. Despite identifying deficiencies in the simulation literature, the paper concludes that experimental research is necessary to provide answers to causal questions that case studies and field research cannot ordinarily provide.