Examining Effectiveness of Judicial Instructions and Gruesome Evidence on Jurors’ Cognitive Processing and Judgments of Eyewitness Evidence
AuthorPerez, Lindsay M.
AdvisorMiller, Monica K.
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Eyewitness testimony is highly influential on jurors’ verdict, however, it is generally unreliable. Erroneous eyewitness identifications are involved in nearly three-fourths of DNA evidence exoneration cases. Jurors often judge eyewitness evidence at face value, and are typically unaware of the variety of factors that influence eyewitness accuracy. The Henderson instructions, implemented in New Jersey after State v. Henderson, inform jurors about the factors that influence eyewitness accuracy in an effort to provide them with more guidance in the evaluation of eyewitness evidence. The present study examined whether modifying the Henderson instructions increases jurors’ comprehension of the instructions and inform their evaluations of eyewitness evidence and verdict. The Henderson instructions were modified by reducing the reading level, shortening sentence length, removing passive phrases, and simplifying the vocabulary of the instructions into ‘plain English’. This study also examined the influence of gruesome evidence on jurors’ judgments. This research, informed by cognitive-experiential self-theory (CEST) and the elaboration likelihood model (ELM), investigated the degree to which judicial instructions and gruesome evidence affect jurors’ cognitive processing level as well as how information processing affects jurors’ judgments. This research investigated the degree to which individual differences in decision-making (i.e., need for cognition, faith in intuition, and legal authoritarianism) relate to jurors’ evaluations of eyewitness evidence and verdict choice. Additionally, this research determined the degree to which cognitive processing measures used in CEST and ELM are interchangeable. Results indicated that the modified Henderson instructions elicited juror sensitivity (i.e., proper evaluation of eyewitness evidence based on the factors involved in the identification) for the assessment of perceived eyewitness accuracy but generally not for verdict choice. Gruesome evidence did not directly influence verdict choice; however, gruesome evidence had an indirect effect on verdict through sadness, contempt, disgust, and cognitive processing level as measured by CEST but not ELM. Although CEST and ELM measures produced similar results, a comparison of each measure of cognitive processing level in predictive models indicated that these measures were not interchangeable. Results potentially aid in the implementation of better methods for promoting critical analysis of eyewitness testimony. Work on jurors’ judgments of eyewitness evidence and cognitive processing will further psychological theory on how jurors formulate their judgments about various aspects of a case, as well as the degree to which the simplified Henderson instructions and gruesome evidence impact cognitive processing.