Iowa State University Capstones, Theses and Graduate Theses and Dissertations Dissertations 2019 Victims as aggressors: Does victim-bystander status influence eyewitness decision-making in showup procedures? Ryan Edward Ditchfield Iowa State University Follow this and additional works at: https://lib.edu/etd Part of the Law Commons, and the Social Psychology Commons Recommended Citation Ditchfield, Ryan Edward, "Victims as aggressors: Does victim-bystander status influence eyewitness decision-making in showup procedures?" (2019). Graduate Theses and Dissertations.edu/etd/17001 This Thesis is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Graduate Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact digirep@iastate.
Victims as aggressors: Does victim-bystander status influence eyewitness decision-making in showup procedures? by Ryan E. Ditchfield A thesis submitted to the graduate faculty in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Major: Psychology Program of Study Committee: Max E. Guyll, Co-major Professor Stephanie Madon, Co-major Professor Jason C. Wells The student author, whose presentation of the scholarship herein was approved by the program of study committee, is solely responsible for the content of this thesis.
The Graduate College will ensure this thesis is globally accessible and will not permit alterations after a degree is conferred. Iowa State University Ames, Iowa 2019 ii TABLE OF CONTENTS Page LIST OF TABLES ………………………………. iv LIST OF FIGURES ………………………………. viii CHAPTER 1 INTRODUCTION.
1 The Use of Showup Procedures in the United States. 2 Case Law Related to Showups. 4 Factors Influencing Eyewitness Identification. 6 Eyewitness Decision-Making.
6 Decision-Making at Identification. 7 Post-Identification Judgments. 9 Victim-Bystander Status and the Frustration-Aggression Hypothesis. 10 Aggression and Eyewitness Decision-Making.
11 Review of Previous Victim-Bystander Research. 26 iii CHAPTER 3 RESULTS. 31 Eyewitness Motivation Measures. 34 Decision-Making at Identification.
35 Post-Identification Judgments. 39 Anger as a Mediator of Post-Identification Judgments. 46 Aggression, Victim-Bystander Status and Eyewitness Decision-Making. 47 Culprit Presence and Eyewitness Decision-Making.
88 APPENDIX A DEMOGRAPHICS QUESTIONNAIRE. 90 APPENDIX B BOGUS COMMUNICATION TASK. 91 APPENDIX C CULPRIT AND INNOCENT SUSPECT PHOTOGRAPHS. 94 APPENDIX D SUSPICION CHECK FORM.
95 APPENDIX E BOGUS CAMPUS THEFT REPORT. 96 APPENDIX F SHORTENED PROFILE OF MOOD STATES. 99 APPENDIX G MANIPULATION CHECKS. 101 APPENDIX I IRB APPROVAL LETTER.
102 iv LIST OF TABLES Page Table 1 Means for Self-Reported Retrospective Negative Affect …………………….… 70 Table 2 MANOVA Analysis of Effects of Manipulations on Retrospective Negative Affect ………………. 71 Table 3 Frequencies and Means for Self-Reported Retrospective Motivations to Avoid Identification Errors ……………………. 72 Table 4 Using Logistic Regression to Test Effects of Manipulations on Dichotomous Motivation Measure ……………. 73 Table 5 MANOVA Analysis of Effects of Manipulations on Continuous Motivation Measures ……………………………………………….
74 Table 6 Identification Rates and Signal Detection Measures……………………………. 75 Table 7 Using Logistic Regression to Test Effects of Manipulations on Identification Rates ………. 76 Table 8 Descriptive Statistics for Immediate Confidence Ratings and Response Latency …………. 77 Table 9 Two-Way ANOVAs Examining Effects of Manipulations on Immediate Confidence Ratings and Response Latency for Identifications and Rejections …………………….
78 Table 10 Means for Post-Identification Judgments of Ability to Identify the Culprit by Eyewitnesses Who Made a Positive Identification………. 79 Table 11 Means for Post-Identification Judgments of Perceived Decision-Making Performance and Willingness to Testify by Eyewitnesses Who Made a Positive Identification ………………. 80 Table 12 MANOVA Analysis of Post-Identification Judgments of Ability to Identify the Culprit by Eyewitnesses Who Made a Positive Identification ……………………. 81 Table 13 MANOVA Analysis of Post-Identification Judgments of Perceived Decision-Making Performance by Eyewitnesses Who Made a Positive Identification ……………….
82 v Table 14 ANOVA Analysis of Post-Identification Willingness to Testify by Eyewitnesses Who Made a Positive Identification ………………………. 83 Table 15 Mediation Effects of Anger on the Relationship between Experimental Effects and Attention Paid to the Culprit …………………….… 84 Table 16 Mediation Effects of Anger on the Relationship between Experimental Effects and Number of Specific Facial Features of the Culprit Attended To …………………….……………………………… 85 Table 17 Mediation Effects of Anger on the Relationship between Experimental Effects and Clarity of Culprit’s Face …………………………… 86 Table 18 Mediation Effects of Anger on the Relationship between Experimental Effects and Willingness to Testify in Court ……………………. 87 vi LIST OF FIGURES Page Figure 1 A graphical representation of identification rates across culprit presence and victim-bystander status ………………………………………………………. 88 Figure 2 A graphic representation of victims’ and bystanders’ retrospective mood scores on each of the six subscales in the Shortened Profile of Mood States Scale ………………………………………………………… 89 vii ACKNOWLEDGMENTS I would like to thank my advisors, Dr.
Max Guyll and Dr. Stephanie Madon, and my committee members, Dr. Gary Wells and Dr. Jason Chan, for their guidance and support throughout the course of this research.
In addition, I would like to thank all of the research assistants who devoted their time to running my experiment, and those who took the time to participant in my experiment for course credit. I would also like to thank my partner, Tiffany Louk, and my good friends here at Iowa State University—Anna Wehde, Tyler Knaplund, and Andreas Miles-Novelo—for their encouragement, support, willingness to listen to my rants about research, and for reminding me to take a break every now and then. Finally, I would like to thank my parents, Ashleigh and Jay Fowler, for helping me to get this far and for supporting me at every step of the way. viii ABSTRACT Police rely on eyewitness identifications to solve crimes, but eyewitnesses can make mistakes.
These mistakes in decision-making can have serious consequences for the criminal justice system. Eyewitnesses can erroneously identify an innocent suspect as the culprit, which could result in a wrongful conviction, or fail to identify a guilty suspect as the culprit, which could result in the culprit avoiding punishment. Drawing on Berkowitz’s (1989) frustration- aggression hypothesis, the current study tested whether eyewitnesses' status as either a victim or a bystander influenced their decision-making processes in a showup procedure after eliminating attention and encoding as possible mediators of the victim-bystander status manipulation. Although victims reported significantly higher feelings of anger than bystanders, victims did not significantly differ from bystanders in identification rates, confidence ratings, response latency, or motivation to catch the guilty culprit.
In addition, victims did not significantly differ from bystanders in their ability to distinguish between guilty culprits and innocent suspects. However, analysis of post-identification judgments revealed that victims who made identified innocent suspects reported paying significantly more attention to the culprit, recalling significantly more specific facial features of the culprit, and having a significantly clearer image of the culprit’s face than bystanders. In addition, victims reported being significantly more willing to testify in court regarding their identification decision than bystanders. These findings suggest that victims may increase the potency of their positive identifications by bolstering responses to post-identification judgments.
Consequently, victims may give the appearance of having a greater ability to accurately identify guilty culprits than bystanders, even in the absence of true differences. INTRODUCTION Police rely on eyewitness identifications to solve crimes, but psychological research and DNA exoneration cases have shown that eyewitness identification evidence is often unreliable (Innocence Project, 2019; Wells & Olson, 2003). Nevertheless, eyewitness testimony remains an important source of evidence in the criminal justice system. Understanding how eyewitnesses make decisions will deepen current understanding of eyewitnesses’ potential for error and allow the field to develop best practices.
Using a novel experimental paradigm in which participants believed that a real crime had occurred, the current study aimed to test whether an eyewitness’ status as either a victim or a bystander influences decision-making in the manner predicted by Berkowitz’s (1989) frustration-aggression hypothesis. To limit the effects under consideration to eyewitness decision-making during and after the identification procedure, the victim-bystander status manipulation was delayed until immediately prior to the showup procedure. This eliminated attention to and encoding of the culprit as possible mediators of the victim-bystander status manipulation. In addition, this study examined decision-making in the context of showups: an identification procedure in which an eyewitness is presented with a single suspect and the eyewitness then decides whether the person presented is the culprit (Smith, Wells, Lindsay, & Penrod, 2017).
Using Berkowitz’s (1989) revised frustration-aggression hypothesis as a theoretical framework, positive identifications during an eyewitness procedure can be defined as aggressive behavior. If victims experience a criminal event as more frustrating than bystanders, victims should experience increased anger and an increased desire to resolve the criminal event by making a positive identification. In addition, victims’ increased aggression should lead to 2 bolstering of self-reported ability to accurately identify the culprit and self-reported decision- making performance. Bolstering increases the potency of a positive identification by making an identification appear more trustworthy to investigators, thereby increasing the likelihood that the criminal event is resolved.
Three objectives were developed to test this theoretical framework. The first objective was to test whether victim-bystander status influenced decision-making at the time of identification, specifically, identification rates, confidence ratings, and response latency. The second objective was to test whether victim-bystander status influenced post-identification judgments of self-reported ability to identify the culprit and self-reported certainty in positive identifications. The third objective was to test whether the effects of victim-bystander status on decision-making were mediated by anger and desire to resolve the criminal event.
By addressing these objectives, this research advances understanding about eyewitness decision-making processes and examines implications for identification performance and eyewitness testimony. The current chapter discusses case law and research relevant to police showup procedures, outlines factors influencing eyewitness identification, and provides an overview of eyewitness decision-making and its relation to Berkowitz’s (1989) frustration- aggression hypothesis. The Use of Showup Procedures in the United States The majority of eyewitness identification studies have focused on the police lineup: a procedure in which a criminal suspect is placed among known innocents (i., fillers) and is then shown to an eyewitness to determine if the eyewitness can identify the suspect as the culprit (Wells & Olson, 2003). This study focused on a less-studied procedure: the showup.
A showup is an identification procedure in which an eyewitness is presented with a single suspect and the eyewitness then decides whether the person presented is the culprit (Smith et al. Recent 3 behavioral science research has demonstrated that showups are suggestive and promote worse applied outcomes than lineups (Smith et al. It is important to note, however, that lineups are not superior to showups because they improve eyewitnesses’ ability to distinguish between innocent suspects and guilty culprits. Indeed, showups have been shown to produce more correct rejections than lineups (Smith et al.
Instead, the lower rate of innocent suspect identifications in lineups can be attributed to differential filler siphoning, whereby false alarms are spread away from the innocent suspect and toward the lineup fillers (Smith et al. As showups have no fillers to draw away false alarms from an innocent suspect, showups result in more false identifications of innocent suspects than lineups. Despite this evidence, showups are still used by approximately 62% of police agencies in the United States. This makes showups second only to photo lineups (used by over 94% of agencies), and considerably more common than other identification procedures such as composite sketches (35.8%), and live lineups (21.
The argument by police in favor of showups is largely practical. To be detained long enough to conduct a live lineup, suspects need to be placed under arrest. Likewise, creating a lineup and presenting it to a witness is time consuming, even if photos of the suspect and potential fillers already exist in police records. Showups, on the other hand, can be conducted quickly and do not require the suspect to be detained for a long period of time (Smith, Wells, Lindsay, Myerson, Kovera, & McAuliff, 2018).
Furthermore, even a detained, arrested suspect can agree to a showup rather than a lineup.