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.

This report integrated quantitative and qualitative methods across two studies to compile descriptive information about forensic psychologists’ occupational socialization processes. We also explored the relation between occupational socialization and forensic psychologists’ objectivity. After interviewing 20 board-certified forensic psychologists, we surveyed 334 forensic psychologists about their socialization into the field. Results indicated that the occupational socialization processes of forensic psychologists, including socialization about objectivity, varied widely across time and situation as the field has developed. Moreover, three hypotheses regarding occupational socialization were supported. It was positively and significantly associated with years of experience, t(284) = 3.63, p < 0.001, 95% CI = 0.05 – 0.16; belief in one’s ability to be objective, t(296) = 9.90, p < 0.001, 95% CI = 0.69 – 1.03; and endorsement of the usefulness of various bias correction strategies, r = 0.38 (p < .001, one-tailed). The implications of these results and directions for future research 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.

A qualitative study with 20 board-certified forensic psychologists was followed up by a mail survey of 351 forensic psychologists in this mixed-methods investigation of examiner bias awareness and strategies used to debias forensic judgments. Rich qualitative data emerged about awareness of bias, specific biasing situations that recur in forensic evaluations, and potential debiasing strategies. The continuum of bias awareness in forensic evaluators mapped cogently onto the “stages of change” model. Evaluators perceived themselves as less vulnerable to bias than their colleagues, consistent with the phenomenon called the “bias blind spot.” Recurring situations that posed challenges for forensic clinicians included disliking or feeling sympathy for the defendant, disgust or anger toward the offense, limited cultural competency, preexisting values, colleagues’ influences, and protecting referral streams. Twenty-five debiasing strategies emerged in the qualitative study, all but one of which rated as highly useful in the quantitative survey. Some of those strategies are consistent with empirical evidence about their effectiveness, but others have been shown to be ineffective. We identified which strategies do not help, focused on promising strategies with empirical support, discussed additional promising strategies not mentioned by participants, and described new strategies generated by these participants that have not yet been subjected to empirical examination. Finally, debiasing strategies were considered with respect to future directions for research and forensic practice.

In an anonymous 4-person economic game, participants contributed more money to a common project (i.e., cooperated) when required to decide quickly than when forced to delay their decision (Rand, Greene & Nowak, 2012), a pattern consistent with the social heuristics hypothesis proposed by Rand and colleagues. The results of studies using time pressure have been mixed, with some replication attempts observing similar patterns (e.g., Rand et al., 2014) and others observing null effects (e.g., Tinghög et al., 2013; Verkoeijen & Bouwmeester, 2014). This Registered Replication Report (RRR) assessed the size and variability of the effect of time pressure on cooperative decisions by combining 21 separate, preregistered replications of the critical conditions from Study 7 of the original article (Rand et al., 2012). The primary planned analysis used data from all participants who were randomly assigned to conditions and who met the protocol inclusion criteria (an intent-to-treat approach that included the 65.9% of participants in the time- pressure condition and 7.5% in the forced-delay condition who did not adhere to the time constraints), and we observed a difference in contributions of −0.37 percentage points compared with an 8.6 percentage point difference calculated from the original data. Analyzing the data as the original article did, including data only for participants who complied with the time constraints, the RRR observed a 10.37 percentage point difference in contributions compared with a 15.31 percentage point difference in the original study. In combination, the results of the intent-to-treat analysis and the compliant-only analysis are consistent with the presence of selection biases and the absence of a causal effect of time pressure on cooperation.

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.