Disgust Reactions from Color Photographs Make Jurors More Conviction Prone

Mock jurors were randomly assigned to view either nongruesome photographs or gruesome photographs in color or black and white. Color gruesome photographs, compared to nongruesome photographs, increased convictions due to the disgust reactions they elicited. This was especially pronounced for mock jurors with relatively higher awareness of their bodily sensations. The effects of gruesome photographs in color on disgust and verdicts were eliminated when the same photographs were presented in black and white. This is the bottom line of a recently published article in Psychology, Public Policy, and Law. Below is a summary of the research and findings as well as a translation of this research into practice.

Featured Article | Psychology, Public Policy, and Law | 2017, Vol. 23, No. 3, pp. 336-350

Seeing Red: Disgust Reactions to Gruesome Photographs in Color (but not in Black and White) Increase Convictions

Authors

Jessica M. Salerno, Arizona State University

Abstract

Jurors are often exposed to emotionally disturbing gruesome photographs of victims of extreme violence. Judges must determine whether the informational value of these photographs outweighs their prejudicial effect on jurors and are left to their assumptions about juror psychology to do so. The current research draws upon the affect infusion model (AIM; Forgas, 1995) to investigate the affective mechanism through which gruesome photographs might operate. A mock jury experiment presented online adults (n=193) with murder trial evidence that included verbal descriptions of the victim’s injuries and neutral photographs in all conditions. Participants were randomly assigned to view (a) only the nongruesome photographs or additional gruesome photographs of the victim in (b) color, or (c) black and white (B&W). Color gruesome (vs. nongruesome) photographs increased convictions via the disgust they elicited. Consistent with the AIM, this was especially so for mock jurors with relatively higher awareness of their bodily sensations. The effects of gruesome photographs in color on disgust and verdicts were eliminated, however, when the same photographs were presented in B&W. A second experiment (n=354) replicated these results and also revealed that viewing color gruesome photographs significantly reduced mock jurors’ sensitivity to a manipulation of defense evidence strength— especially among jurors with relatively higher bodily awareness. Thus, gruesome photographs can increase convictions via direct and indirect affect infusion. Presenting gruesome photographs in B&W might reduce jurors’ emotional reactions while maintaining their probative information.

Keywords

jury decision making, emotion, gruesome photographs, disgust, blame

Summary of the Research

“The current studies draw upon the affect infusion model (AIM), which describes how negative emotion resulting from emotionally evocative information (e.g., gruesome photographs of a murder victim) can influence the way we process other information and ultimately color our judgments (e.g., verdicts) to be in line with that negative emotion. To test this model in a jury context, two experiments assessed mock jurors’ negative emotions and verdicts in a murder case that included verbal descriptions of the victim’s injuries and neutral photographs in all conditions. Mock jurors were randomly assigned to see only these nongruesome photographs, or additional gruesome photographs of the victim in B&W or color (Studies 1 and 2). This design enabled a test of how viewing gruesome photographs might increase convictions through direct and indirect affect infusion” (p.336).

“The second study manipulates defense evidence strength to test whether gruesome photographs increase convictions by biasing jurors’ processing of other evidence to justify blaming the defendant (i.e., indirect affect infusion). That is, whether gruesome photographs make mock jurors less sensitive to strong (vs. weak) defense evidence. Application of the AIM to this context also suggests an intervention that might ameliorate affect infusion effects on verdicts: presenting the gruesome photographs in a less emotionally evocative way (i.e., in B&W)” (p.336).

“…To test the affective mechanisms underlying the gruesome photographs effect, I hypothesized the following indirect and conditional indirect effects of gruesome photographs on verdicts. Hypothesis 1: Gruesome photographs in color (but not in B&W) increase convictions through increased negative emotion…Hypothesis 2: Color gruesome photographs will have a stronger effect as mock jurors’ bodily awareness increases…Hypothesis 3: Gruesome photographs in color will reduce jurors’ sensitivity to strong defense evidence. The AIM and CCM [culpable control model of blame] suggest that if jurors’ negative emotions are aroused by gruesome photographs, they will be less likely to process, retrieve, and apply evidence that is incongruent with their negative emotion and resulting need to blame someone for the transgression (i.e., defense evidence)” (p.339).

“Study 1 demonstrated support for the hypotheses. First, viewing color gruesome photographs of a murder victim made mock jurors more conviction prone because they increased disgust; but this effect did not generalize to less vivid B&W versions of the same photographs…Consistent with the AIM, even though the color and B&W gruesome photographs contained the same information relevant to the verdict decision, only seeing the relatively more vivid, color photographs produced enough disgust to be infused into verdicts and increase convictions. Second, this effect was stronger among mock jurors who tend to be relatively more aware of their bodily sensations…Of note, anger was not a mediator at any level of bodily awareness because-event though both anger and disgust increased convictions-the gruesome photographs increased only disgust” (p.342).

“Support for the three hypotheses designed to test the theory that viewing gruesome photographs in color will increase convictions through affective disgust-based channels were largely replicated. First, viewing the more vivid color gruesome photographs of a murder victim again made mock jurors more conviction prone because they increased disgust, relative to when they only read verbal descriptions of the injuries and saw neutral photographs. Second, this effect did not generalize to less vivid B&W versions of the same photographs. The one exception to the replication pattern, however, was that the direct comparison of color to B&W gruesome photographs dropped from significant in Study 1 to marginal in Study 2. Third, mock jurors’ disgust reactions to the color gruesome photographs increased convictions among those who tend to be relatively more aware of the sensations in their body. Consistent with Study 1, anger did not explain any effects of color gruesome photographs on verdicts” (p.344).

“The new hypothesis that presenting color gruesome photographs would make jurors less sensitive to strong defense evidence was also supported among those relatively higher in awareness of their bodily sensations. That is, reading strong (vs. weak) defense evidence made them perceive the defense evidence as stronger and, in turn, reduced their likelihood of voting guilty as long as their negative affect was not roused (i.e., in the no-gruesome control). This sensitivity to defense evidence strength was significantly reduced, however, when their disgust was roused by gruesome photographs in either color or B&W. Mock jurors with relatively lower bodily awareness were sensitive to defense evidence strength no matter how vivid the photographic evidence. This suggests that the desensitization among jurors with relatively higher bodily awareness was instigated by their affective response to the color gruesome photographs” (p.345).

Translating Research into Practice

“Judges are gatekeepers who decide whether emotionally disturbing evidence should be allowed in court. The Federal Rules of Evidence (Rule 403) state that judges can exclude such evidence if its prejudicial impact outweighs its probative value, but provide little guidance about how to judge such an issue. Thus, judges-as well as prosecutors and defense attorneys making admissibility arguments-are in need of psychological research that demonstrates the extent to which gruesome photographs can affect verdicts through probative and/or affective channels. Judges should be aware that color gruesome photographs can make jurors more conviction prone because they induce disgust-even when the photographs add little to no probative information beyond other evidence. Further, judges and attorneys should be aware that viewing gruesome photographs in color or B&W can prejudice jurors against strong defense evidence, rending them less sensitive to its strength and more motivated to discount it” (p.346).

“…The goal of the current studies is not to argue that the emotional response to gruesome photographs should always be considered prejudicial, but instead to demonstrate that they can affect verdicts via emotion directly and indirectly through biasing their processing of defense evidence-even when they do not provide additional probative information. It is up to judges making admissibility decisions to determine whether these emotion-drive effects are legally prejudicial and to weigh them against the photographs’ potential probative value. In cases where the color/quantity of blood is irrelevant to the legal issues being considered to judge guilt, presenting the gruesome photographs in a less prejudicial way (i.e., in a les vivid B&W version) an prevent jurors’ disgust response to color gruesome photographs from coloring their judgments…Finally, attorneys might want to consider assessing jurors’ likelihood of being relatively more or less aware of their emotional reactions in these types of cases during jury selection…” (p.346-347).

Other Interesting Tidbits for Researchers and Clinicians

“The current results make theoretical contributions by furthering our understanding of how and why gruesome photographs affect blame judgments. The current results provide support for the AIM’s direct affect infusion: mock jurors might consult their negative emotions heuristically while making a verdict judgment and, as a result, misattribute their negative emotion due to seeing a victim of a horrific crime to how they feel about the defendant’s guilt. The results also support the indirect route to affect infusion described by the AIM and the CCM: negative emotions resulting from color gruesome photographs might motivate jurors to discount strong defense evidence…The findings are also theoretically consistent with moral psychology studies demonstrating that disgust (but not other negative emotions like sadness) is infused into moral judgments of transgressions among those who are relatively more sensitive to their bodily sensations. Finally, the finding that disgust, but not anger, increased convictions contributes to the growing theoretical discussion of differences between the effect of anger and disgust on moral judgments” (p.346).

Join the Discussion

As always, please join the discussion below if you have thoughts or comments to add!

Authored by Amber Lin

Amber Lin is a volunteer in Dr. Zapf’s research lab at John Jay College of Criminal Justice. She graduated from New York University in 2013 with a B.A. (honors) and hopes to obtain her PhD in forensic clinical psychology. Her research interests include forensic assessment, competency to stand trial, and the refinement of instruments used to assess the psychological states of criminal defendants.

Experience Trumps Science in Influencing Jurors

Forensic science match evidence presented by a highly experienced examiner with an impressive background was judged to be stronger and more persuasive than identical evidence presented by a less experienced examiner with a less impressive background. This is the bottom line of a recently published article in Psychology, Public Policy, and Law. Below is a summary of the research and findings as well as a translation of this research into practice.

Featured Article | Psychology, Public Policy, and Law | 2016, Vol. 22, No. 4, 401-413

Science, Technology, or the Expert Witness: What Influences Jurors’ Judgments About Forensic Science Testimony?

Authors

Jonathan J. Koehler, Northwestern University
Michael J. Saks, Arizona State University and University of Haifa
N.J. Schweitzer, Arizona State University
Dawn E. McQuiston, Wofford College

Abstract

The impact of forensic science evidence on jurors’ judgments is critically important to the criminal justice system. The assignment of low or high weight to such testimony can be the difference between acquittal or conviction. Many of the traditional forensic sciences (e.g., fingerprints and bitemarks) draw their strength largely from the subjective judgments of examiners who testify about whether evidentiary prints or other markings are consistent with (or “match”) known markings from a person or object. In an online experiment (Experiment 1) and a realistic jury simulation using actual jurors or jury-eligible adults (Experiment 2), this article investigates 3 factors that might affect how jurors think about and use forensic science evidence. These factors are (a) whether the forensic science method had been scientifically tested, (b) the forensic scientist’s background and experience, and (c) the sophistication of the forensic science technology. The results show a strong and consistent effect for examiner background and experience on evidence strength judgments, no effect for forensic technology sophistication, and a limited and inconsistent effect for scientific testing (present in the online experiments, absent in the realistic jury simulation). These findings raise concerns about potential undue influence of examiner background and experience on jurors’ judgments and lack of clear influence of scientific testing. The implications of our findings for criminal justice practices and policies are considered.

Keywords                                                                                              

Evidence, experience, forensic science, jury decision making, testing

Summary of the Research

“The research presented here seeks to discover how lay jurors are influenced by forensic science expert testimony that varies along the three dimensions …(method testing, examiner experience, and technological sophistication of method)…To explore the possible effects of these variables, we conducted two experiments, first online (Experiment 1) and then using a videotaped trial with deliberating groups of community members (Experiment 2)…for both experiments, we examined the impact of scientific testing of a forensic method, an examiner’s experience, and the technological sophistication of the method on simulated jurors’ judgments about the forensic science testimony” (p. 403).

“Experiment 1 utilized written materials administered to an online sample of community member participants. We presented one of two separate trial summaries (a sexual assault case involving bitemark evidence and an attempted murder case involving fingerprint evidence) to a sample of participants…Within each summary, we manipulated three independent variables (Forensic Technique Scientifically Tested: yes or no), (Expert’s Experience: high or low), (Technology Level of the Forensic Technique: high or low) …For both trials, we created a ~ 700 word summary that included background information, direct examination testimony from a forensic scientist, and cross-examination of that expert. In both trials, we experimentally manipulated the amount of scientific testing the examiner’s technique had undergone, the experience of the examiner, and the technology used by the examiner” (p. 403-404).

“The results for the bitemark and fingerprint cases were similar in two different criminal case scenarios. In both cases, jurors were sensitive to whether the forensic technique in question had been scientifically tested. Techniques that had been scientifically validated were viewed as providing stronger evidence of identity. However, this effect did not carry through to the guilt [determinations]… in both cases, a majority of jurors voted to acquit in all experimental conditions” (p. 405-406).

“Examiner experience was important to our jurors on both evidence and guilt. This result supports the possibility that experience is a powerful, central trait for people who are called upon to assess the value of information that another person or a process has provided…Experience may also serve as an antidote to the uncertainty that exists when people tell us things that we cannot evaluate or interpret for ourselves. In our study, it appears that jurors leaned on the experience of the testifying forensic scientist to guide their assessments of the soundness of his findings” (p. 406).

“In our second experiment, we went to great lengths to provide mock jurors with a more ecologically valid experience that included realistic trial procedures, video testimony, and group deliberations…Using the same conceptual framework as the materials presented to the online participants, we created a ~7,500 word trial transcript of the fingerprint case used in Experiment 1. We developed the fingerprint case rather than the bitemark case for the video because fingerprint evidence is a more common, relatively well-understood forensic science, and because the presence of a match in this case is not necessarily dispositive on the matters of guilt due to the potential ambiguities about when the print was deposited…As in Experiment 1, the eight trial videos differed in whether the forensic method had or had not been tested, whether the examiner was highly experienced or not, and whether the technology employed by the examiner was sophisticated or simple” (p. 408).

“As in the online experiment, jurors assigned more weight to the forensic science evidence when the testifying witness was a highly experienced examiner. Why do we find effects for experience but not for testing? One possibility is that people believe fingerprint analyses are quite reliable when performed by the right person. Under this belief system, an examiner who has a great deal of experience is also one who has great expertise and competence (p. 409).

“This finding suggests that jurors use the background and experience of an expert as a proxy for the value of the evidence the expert provides. Such a process is consistent with heuristic models that are premised on the idea that decision makers who lack the motivation or ability to assess the value of available substantive information rely on easily understood peripheral cues…to judge the quality of that information. This process is also consistent with literature that shows an expert witness’ perceived credibility is influenced by the witness’ status and experience level and such noncontent cues as likability and confidence” (p.410).

Translating Research into Practice

“Our research could have implications for criminal justice policies and practices. First, if jurors are responsive to peripheral cues rather than content cues when evaluating forensic evidence, then courts need to be especially vigilant about enforcing their gatekeeping duties under Daubert v. Merrell Dow Pharmaceutical, Inc. The danger in failing to apply Daubert’s tough reliability test on the front end is that jurors will presume that admitted forensic evidence is accurate evidence, and cross-examination that exposes substantive scientific weaknesses will be ignored. Second, jurors’ apparent belief that evidence provided by more experienced forensic scientists is more accurate and valuable than the identical evidence provided by less experienced forensic scientists has no basis in reality. As noted earlier, research on expertise finds that experience and credentials are a poor predictor of accuracy, and forensic science does not appear to be an exception” (p. 411).

“If future research confirms jurors’ lack of sensitivity to something so important as scientific validation or lack thereof, along with the excessive value jurors place on examiners’ experience and qualifications, then courts, legislatures, rules committees, and scientific bodies charged with making policy recommendations would be wise to promote policies, rules and instructions that minimize the significance of a forensic expert’s background, and emphasize the quality and extent of scientific testing of the forensic techniques being used…Moreover, attorneys could play a more active role in regard to these issues by emphasizing these matters in their closing arguments and by asking courts to provide jurors with appropriate instruction” (p. 411).

Other Interesting Tidbits for Researchers and Clinicians

“Deliberation had little impact on jurors’ responses to our key dependent measures. For the most part, jurors felt the same way about the evidence and the likely guilt of the defendant following deliberation as they had heading into deliberation…One reason why deliberation has little impact may be that people think through the implications of the evidence on their own prior to deliberation, particularly when expressly invited (by our predeliberation questionnaire) to do so. At the same time, we note that deliberation did change the verdicts of nearly one out of five jurors, almost exclusively moving them from a predeliberation verdict of guilty to a postdeliberation verdict of not guilty. This result is consistent with a few other studies that indicated that deliberation decreases conviction rates. Though not of central concern in the present study, continuing research is needed to identify the conditions under which deliberation alters individuals’ predeliberation preferences” (p. 409-410).

“A word of caution about our findings related to experience: we varied a number of facets of the forensic examiner’s experience simultaneously to provide study participants with an examiner who would be seen as either very experienced or very inexperienced. Our data do not speak clearly to the amount of experience required to persuade jurors to abide by the word of the examiner. Nor do our data speak to which facets of experience (e.g. amount of training, cases worked, courtroom appearances) are more and less influential. This refinement is left for another study…” (p. 410).

Join the Discussion

As always, please join the discussion below if you have thoughts or comments to add!

Authored by Amber Lin

Amber Lin is a volunteer in Dr. Zapf’s research lab at John Jay College of Criminal Justice. She graduated from New York University in 2013 with a B.A. (honors) and hopes to obtain her PhD in forensic clinical psychology. Her research interests include forensic assessment, competency to stand trial, and the refinement of instruments used to assess the psychological states of criminal defendants.