Understanding Confidence: Eyewitness Testimony as a Model Case

日常生活需要人们了解另一个人对他/她的记忆的信心程度。例如，当配偶说，“我很确定我锁了门”，你会把这句话理解为你应该再检查一下锁吗？对这种自信表达的解释带来了重要的认知挑战，并可能受到许多不同因素的影响。可能影响这些对信心的解释的认知偏差和可能限制这些偏差影响的表达信心的方法是具有广泛应用的重要研究领域。目前的项目在目击者鉴定的背景下审查这些因素。当一名目击者从指认者中指认出某个人，并说：“我很确定就是他。”我们怎么知道警察、陪审员和其他人会按照他的意图来解读这种自信的表达呢？虽然存在大量关于目击证人信心和(a)其与鉴定准确性的关系，(b)其对陪审员的影响，以及(c)其易受鉴定后反馈影响的文献，但对于其他人如何理解目击证人信心的口头表达知之甚少。该项目的成果是更彻底地了解影响对信心的解释的认知因素，预计将对涉及对他人信心的解释的司法程序等环境产生广泛影响。这个项目调查人们如何理解目击者对他/她从一排面孔中识别的准确性的信心的口头表达。有三个目标：首先，该项目检查目击证人为他/她的自信程度辩护的特定内容（例如，“我很确定是他，因为我记得他的下巴”）如何影响人们如何理解目击证人的自信陈述。其次，有各种各样的认知偏见导致个体误解确定性的口头表达。例如，越来越多关于“结果-严重性偏差”的研究表明，相同的口头概率短语（例如，“有点可能”）被解释为表示更高的数字可能性，当该短语指的是更严重的事件而不是不那么严重的事件时。该项目考虑目击者的自信表达是否容易受到由相同类型的认知偏见引起的误解的影响。第三，我们提出的实验探讨这些认知偏差的有害影响是否可以通过数字而不是口头表达信心来减轻。总的来说，该项目将填补人们如何理解目击者对指认的信心这一知识的严重缺乏。此外，关于确定性的口头表达容易受到误解的认识可以：(a)指导警察从目击者那里获得确定性的数字估计；(b)提醒警察、律师、法官和陪审员在解释确定性的口头表达时注意潜在的陷阱。

Everyday situations require individuals to understand another person's level of confidence in his/her memory. For example, when a spouse says, "I'm pretty sure I locked the door" do you interpret that statement as indicating that you should double check the lock or not. Interpretation of such expressions of confidence present important cognitive challenges and can be influenced by a number of different factors. The cognitive biases that can influence these interpretations of confidence and the approaches to expressing confidence that might limit the impact of these biases are important areas of research with wide-ranging applications. The current project examines these factors in the context of eyewitness identification. When an eyewitness identifies someone from a lineup and states, "I'm pretty sure it's him," how do we know that police, jurors and others will interpret this expression of confidence in the way that it was intended? While a large literature exists on eyewitness confidence and (a) its relationship with identification accuracy, (b) its influence on jurors, and (c) its vulnerability to influence from post-identification feedback, very little is known about how other people understand the verbal expressions of eyewitness confidence. The outcomes of this project in terms of a more thorough understanding of the cognitive factors that influence interpretations of confidence are anticipated to have broad implications for settings, such as judicial proceedings, that involve the interpretation of another person's confidence.This project investigates how people understand an eyewitness's verbal expression of confidence in the accuracy of his/her identification from a lineup of faces. There are three goals: first, the project examines how the particular content of an eyewitness's justification for his/her level of confidence (e.g., "I'm pretty certain it's him because I remember his chin") influences how people understand the eyewitness's confidence-statement. Second, there are a variety of cognitive biases that cause individuals to misinterpret the verbal expressions of certainty. For example, mounting research on the 'outcome-severity bias' shows that the identical verbal probability phrase (e.g., "it is somewhat likely") is interpreted as denoting a higher numerical likelihood when that phrase refers to more severe events rather than less severe events. The project considers whether eyewitness expressions of confidence are vulnerable to misunderstandings that are caused by the same kinds of cognitive biases. Third, the proposed experiments investigate whether the harmful influence of these cognitive biases can be mitigated by expressing confidence numerically instead of verbally. Overall, the project will fill a profound lack of knowledge about how people understand eyewitness confidence in a lineup identification. Moreover, the knowledge that verbal expressions of certainty are vulnerable to misinterpretations may: (a) guide police to obtain a numerical estimate of certainty from eyewitnesses; and (b) alert police, lawyers, judges and jurors to potential pitfalls about interpreting verbal expressions of certainty.