A New Method of Studying Confidence Malleability: Self-Sourced Misinformation as Post-Identification Feedback
Eyewitness confidence is often used by judges and jurors as a cue to accuracy. Despite this, confidence is not always related to accuracy as confidence is malleable over time and subject to suggestion. One way in which confidence can be influenced by outside factors is through post-identification feedback. The post-identification feedback effect is the finding in which participants report remembering higher confidence in their identification and a better memory for the crime when they are told they correctly identified the suspect relative to those who do not receive feedback. In the current dissertation, research on post-identification feedback is merged with studies on the misinformation effect which shows that exposing people to misleading information after viewing an event can alter their later memories for that event. The main goal of the dissertation is to investigate whether giving participants a misleading reminder about their identification confidence can affect their later recall.
Initially, two pilot studies were conducted to explore the kind of scale to best use to measure and manipulate confidence. In the main dissertation studies, participants completed a two-session experiment. In session one, they watched a mock crime video, identified the suspect from a lineup, and gave their confidence in this identification. In session two, they were reminded of their confidence. However, for some participants, this reminder was manipulated to be 20 points higher or lower than what the participant originally reported. In Study 2, the effect of this kind of misinformation feedback was contrasted with typical feedback informing the participant whether they correctly identified the suspect.
In both studies, resulted revealed that nearly all participants failed to detect the manipulation between their original confidence statement and the manipulated one provided to them. This manipulation had ripple effects such that participants led to believe their confidence was higher than originally reported later remembered having more confidence in their identification and having a better viewing experience at the time of the crime with parallel effects for the manipulation in the opposite direction. Study 2 revealed that although misinformation and typical feedback are similar, there are some differences. Specifically, typical disconfirming feedback is less powerful than typical confirming feedback, but this is not true for the two kinds of misinformation feedback. Implications for police procedure and the importance of only relying on initial confidence as a cue to accuracy are discussed.