Younan Mariam, Martire Kristy A
School of Psychology, The University of New South Wales, Kensington, NSW, Australia.
Front Psychol. 2021 Dec 23;12:785677. doi: 10.3389/fpsyg.2021.785677. eCollection 2021.
With the use of expert evidence increasing in civil and criminal trials, there is concern jurors' decisions are affected by factors that are irrelevant to the quality of the expert opinion. Past research suggests that the likeability of an expert significantly affects juror attributions of credibility and merit. However, we know little about the effects of expert likeability when detailed information about expertise is provided. Two studies examined the effect of an expert's likeability on the persuasiveness judgments and sentencing decisions of 456 jury-eligible respondents. Participants viewed and/or read an expert's testimony (lower vs. higher quality) before rating expert persuasiveness (via credibility, value, and weight), and making a sentencing decision in a Capitol murder case (death penalty vs. life in prison). Lower quality evidence was significantly less persuasive than higher quality evidence. Less likeable experts were also significantly less persuasive than either neutral or more likeable experts. This "penalty" for less likeable experts was observed irrespective of evidence quality. However, only perceptions of the foundational validity of the expert's discipline, the expert's trustworthiness and the clarity and conservativeness of the expert opinion significantly predicted sentencing decisions. Thus, the present study demonstrates that while likeability does influence persuasiveness, it does not necessarily affect sentencing outcomes.
随着专家证据在民事和刑事审判中的使用日益增加，人们担心陪审员的决定会受到与专家意见质量无关的因素影响。过去的研究表明，专家的亲和力会显著影响陪审员对可信度和价值的判断。然而，当提供关于专业知识的详细信息时，我们对专家亲和力的影响知之甚少。两项研究考察了专家亲和力对456名符合陪审员资格的受访者的说服力判断和量刑决定的影响。参与者在对专家的说服力（通过可信度、价值和权重）进行评分，并在一个国会山谋杀案中做出量刑决定（死刑与终身监禁）之前，观看和/或阅读了专家的证词（质量较低与较高）。质量较低的证据明显不如质量较高的证据有说服力。不太有亲和力的专家也明显不如中立或更有亲和力的专家有说服力。无论证据质量如何，都观察到了对不太有亲和力的专家的这种“惩罚”。然而，只有对专家学科的基本有效性、专家的可信度以及专家意见的清晰度和保守性的看法能显著预测量刑决定。因此，本研究表明，虽然亲和力确实会影响说服力，但不一定会影响量刑结果。
