Garrett, Brandon L., Crozier, William E., Modjadidi, Karima, Liu, Alice J., Kafadar, Karen, Yaffe, Joanne, and Dodson, Chad S.
We examine a new paradigm for jury instructions regarding eyewitness testimony, in which the judge provides concise reasons why jurors should discount an eyewitness's courtroom confidence and instead focus on the eyewitness's confidence at the time of a police lineup. In Study 1, 1,614 participants ("mock jurors"), representative of the U.S. population, viewed videos of eyewitness testimony and judicial instructions. We found that instructions using the reason-based paradigm reduced guilty votes. Study 2 (N = 2,911) examined whether reason-based instructions sensitized jurors to weak (low initial confidence) versus strong (high initial confidence) eyewitness identifications, and whether the instructions needed to be directive ("You should consider ..."). Jurors who heard the instructive, reason-based instructions better differentiated between more and less reliable eyewitnesses relative to the other instruction conditions. These results suggest that reason-based jury instructions can increase discriminability among laypersons, and that judges should be mindful in phrasing and communicating such instructions. General Audience Summary: Eyewitnesses who are highly confident when they pick someone from a lineup are more likely to be accurate than eyewitnesses who have low confidence in their decisions. However, this confidence-to-accuracy relationship breaks down by the time an eyewitness testifies at trial; that is, an eyewitness's confidence on the stand is not indicative of accuracy. Unfortunately, an eyewitness's confidence can increase over time even though their memory does not get more accurate, a phenomenon known as "confidence inflation." Confidence inflation is a large problem for the criminal legal system, as jurors find highly confident eyewitnesses very persuasive. Indeed, many wrongful convictions happen because an inaccurate eyewitness testified with high confidence at trial. Jury instructions, which are read to the jury at the end of a trial to inform them how they might weigh different pieces of evidence, have largely been unsuccessful in changing how jurors view eyewitness evidence, and have never explained confidence inflation. We draw on psychological research that finds providing an explanation, or reason, is the most effective way to convince people to rely on one piece of information (lineup confidence) over another (courtroom confidence). Thus, we crafted "reason-based instructions" that briefly explain the memorial processes that lead to confidence inflation and emphasize considering lineup confidence over courtroom confidence. In two experiments, we presented a video of an eyewitness giving testimony, a video of a judge giving our novel reason-based instructions or control instructions, and then asked the participants to serve as mock jurors by voting "guilty" or "not guilty." We found reason-based instructions decreased guilty votes, relative to non-reason-based instructions, for weak eyewitness evidence. Additionally, reason-based instructions that directed jurors on how to weigh confidence decreased guilty votes for weak eyewitness evidence, but not strong eyewitness evidence—an ideal instruction for use in the real courtrooms. [ABSTRACT FROM AUTHOR]