Neal, Tess

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.

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.

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.

This study sought to identify stigma differences between HIV/AIDS and other sexually transmitted infections (STIs). Interviewees from Alabama, USA (n=537) rated two types of stigma (damage to social reputation and “moral weakness”) for seven infections ranging from “nuisance” conditions (e.g., pubic lice) to life-threatening disease (e.g., HIV/AIDS). When asked which of the seven STIs would be most damaging to reputation, 74.8% of respondents chose HIV/AIDS. However, when asked to choose which STI represented moral weakness in infected persons, HIV/AIDS was rated as significantly lower than the other STIs, which suggests that HIV/AIDS is perceived differently than non-HIV STIs. This study addresses the possibility that advances in public awareness of HIV/AIDS have not necessarily been extrapolated into awareness of other STIs. Clinicians should be aware of these high levels of stigma as potential barriers to treatment for all STIs. Public health officials should consider the impact of undifferentiated stigma on STI prevention messages.