This study examined how manipulations of likeability and knowledge affected mock jurors’ perceptions of female and male expert witness credibility (N=290). Our findings extend the person perception literature by demonstrating how warmth and competence overlap with existing conceptions of likeability and credibility in the psycholegal domain. We found experts high in likeability and/or knowledge were perceived equally positively regardless of gender in a death penalty sentencing context. Gender differences emerged when the expert was low in likeability and/or knowledge; in these conditions the male expert was perceived more positively than the comparable female expert. Although intermediate judgments (e.g., perceptions of credibility) were affected by our manipulations, ultimate decisions (e.g., sentencing) were not. Implications for theory and practice are discussed.

There is substantial controversy over the extent to which social science should be used in jury selection. Underlying the debate are two competing interests in the make-up of a jury: a privilege to strike prospective jurors on subjective grounds, which supports scientific jury selection, and a collective interest of citizens to be free from exclusion from jury service, which does not. While the incommensurability of the interests precludes resolution of the controversy in the abstract, specific solutions are possible. Using the example of selection of jurors based upon their respective levels of extraversion, we describe how the competing interests frequently do not apply to concrete cases. In the subsequent analysis, we show that, rhetoric notwithstanding, a normative preference for adhering to tradition and institutional inertia are the primary instrumental considerations for determining whether peremptory challenges based upon personality traits like extraversion ought to be allowed. Consistent with this analysis, we conclude that the practice of striking jurors based upon estimates of such personality traits is appropriate.

The knowledge of experts presumably affects their credibility and the degree to which the trier of fact will agree with them. However, specific effects of demonstrated knowledge are largely unknown. This experiment manipulated a forensic expert’s level of knowledge in a mock trial paradigm. We tested the relation between low versus high expert knowledge on mock juror perceptions of expert credibility, on agreement with the expert, and on sentencing. We also tested expert gender as a potential moderator. Knowledge effects were statistically significant; however, these differences carried little practical utility in predicting mock jurors’ ultimate decisions. Contrary to hypotheses that high knowledge would yield increased credibility and agreement, knowledge manipulations only influenced perceived expert likeability. The low knowledge expert was perceived as more likeable than his or her high knowledge counterpart, a paradoxical finding. No significant differences across expert gender were found. Implications for conceptualizing expert witness knowledge, credibility, and their potential effects on juror decision-making are discussed.

The essential tasks for an expert witness are to be prepared, to be effective and credible on the stand, and to manage well the demands of cross-examinations. Most novice experts are excessively anxious about their testimony. Effective experts are well-oriented to the legal and scientific context of court testimony. This chapter reviews research-backed tips for preparing for expert testimony.

The majority of trust research has focused on the benefits trust can have for individual actors, institutions, and organizations. This “optimistic bias” is particularly evident in work focused on institutional trust, where concepts such as procedural justice, shared values, and moral responsibility have gained prominence. But trust in institutions may not be exclusively good. We reveal implications for the “dark side” of institutional trust by reviewing relevant theories and empirical research that can contribute to a more holistic understanding. We frame our discussion by suggesting there may be a “Goldilocks principle” of institutional trust, where trust that is too low (typically the focus) or too high (not usually considered by trust researchers) may be problematic. The chapter focuses on the issue of too-high trust and processes through which such too-high trust might emerge. Specifically, excessive trust might result from external, internal, and intersecting external-internal processes. External processes refer to the actions institutions take that affect public trust, while internal processes refer to intrapersonal factors affecting a trustor’s level of trust. We describe how the beneficial psychological and behavioral outcomes of trust can be mitigated or circumvented through these processes and highlight the implications of a “darkest” side of trust when they intersect. We draw upon research on organizations and legal, governmental, and political systems to demonstrate the dark side of trust in different contexts. The conclusion outlines directions for future research and encourages researchers to consider the ethical nuances of studying how to increase institutional trust.

Examinations of trust have advanced steadily over the past several decades, yielding important insights within criminal justice, economics, environmental studies, management and industrial organization, psychology, political science, and sociology. Cross-disciplinary approaches to the study of trust, however, have been limited by differences in defining and measuring trust and in methodological approaches. In this chapter, we take the position that: 1) cross-disciplinary studies can be improved by recognizing trust as a multilevel phenomenon, and 2) context impacts the nature of trusting relations. We present an organizing framework for conceptualizing trust between trustees and trustors at person, group, and institution levels. The differences between these levels have theoretical implications for the study of trust and that might be used to justify distinctions in definitions and methodological approaches across settings. We highlight where the levels overlap and describe how this overlap has created confusion in the trust literature to date. Part of the overlap – and confusion – is the role of interpersonal trust at each level. We delineate when and how interpersonal trust is theoretically relevant to conceptualizing and measuring trust at each level and suggest that other trust-related constructs, such as perceived legitimacy, competence, and integrity, may be more important than interpersonal trust at some levels and in some contexts. Translating findings from trust research in one discipline to another and collaborating across disciplines may be facilitated if researchers ensure that their levels of conceptualization and measurement are aligned, and that models developed for a particular context are relevant in other, distinct contexts.

This study sought to investigate the relation between expert witness likeability and juror judgments of credibility and sentencing. Two actors playing expert witnesses were trained to present themselves as high and low in likeability in a standard testimony scenario involving capital trial sentencing. The effects of extraversion and gender in mock jurors in attending to expert testimony were also examined. The dependent variables were the perceptions of the witnesses’ credibility and agreement with testimony and the participants were 210 psychology undergraduates. Likeability of expert witnesses was found to be significantly related to judgments of trustworthiness of the experts, but not related to confidence or knowledge of the experts or to the mock juror sentencing decisions. Women participants rated high likeable experts as more credible than low likeable experts; men did not. For men jurors, agreement with testimony increased as extraversion increased. However, for women jurors, agreement with testimony decreased as extraversion increased. The results suggest that likeability can be an important element of source credibility, and that attorneys and trial consultants now have an empirical foundation for addressing likeability as part of witness preparation.