Perceptions of bias and credibility of male and female clinical psychologist and psychiatrist expert witnesses presenting clinical information in the courtroom

Expert witness credentials and gender have independently been shown to influence jurors' perceptions of expert witness credibility and legal decision-making. This study examined how manipulations of expert witness gender (Male/Female) and profession (Consultant Clinical Psychologist/Consultant Psychiatrist) together affected mock jurors' perceptions of expert witness credibility, judgements, and decision-making. Mock jurors (N = 182; 80.9 % were White) were recruited from England and Wales and were randomly assigned to watch a video-recorded mock expert witness testimony. Participants rated the expert witness using the Witness Credibility Scale and reported the likelihood of assigning the defendant to a guilty verdict. Results showed significant interaction effects of expert witness gender and profession on jurors' perceptions of their likeability, trustworthiness, knowledge, and total credibility. Male psychiatrists, followed by female clinical psychologists, received the highest scores in most credibility variables. Varied main effects of expert witness gender and profession on credibility were also found. Overall, jurors' ratings of expert witness credibility, when controlled by the expert's gender and profession, predicted jurors' determination of guilt. This study provides evidence of a potential interaction effect between profession and gender in expert witness credibility and supports existing research linking credibility with ultimate decision-making. More research is needed to understand jurors' unconscious biases and cognitive processes in making legal decisions.