Effects of inconsistencies in eyewitness testimony on mock-juror decision-making

In attempting to impeach eyewitnesses, attorneys often highlight inconsistencies in the eyewitness's recall. This study examined the differential impact of types of inconsistent testimony on mock-juror decisions. Each of 100 community members and 200 undergraduates viewed one of four versions of a videotaped trial in which the primary evidence against the defendant was the testimony of the eyewitness. I manipulated the types of inconsistent statements given by the eyewitness in the four versions: (1) consistent testimony, (2) information given on-the-stand but not given during the pre-trial investigation, (3) contradictions between on-the-stand and pre-trial statements, and (4) contradictions made on the witness stand. Subjects exposed to any form of inconsistent testimony were less likely to convict and found the defendant less culpable and the eyewitness less effective. These effects were larger for contradictions than for information given on the stand but not during pre-trial investigations. ^

The National Institute of Justice guide for eyewitness identification evidence: Can it improve juror decision-making?

Mistaken eyewitness identifications of innocent lead to more false convictions in the United States than any other cause. In response to concerns about the reliability of eyewitness evidence, the National Institute of Justice (NIJ) in 1999 published a Guide for the gathering and preservation of eyewitness evidence by law enforcement personnel. Previous research has shown that eyewitness identifications are more accurate when obtained using procedures recommended in the NIJ Guide. This experiment assessed whether informing jurors about the Guide can improve their ability to discriminate between eyewitness identifications likely to be accurate and those likely to be inaccurate and, if so, how to most effectively provide jurors with such information. ^ Seven hundred sixteen U.S. citizens who reported for criminal jury duty participated. Half of the participant jurors read a summary of an armed robbery trial in which the police followed the NIJ Guide when obtaining an eyewitness identification of the defendant. The other half read about an identical case in which the police did not follow the Guide. Jurors received information about the Guide from a court-appointed expert witness, one of the attorneys in the case, the trial judge, the judge in combination with one of the attorneys, or from no one (in the control groups). Jurors then rendered a verdict in the case and answered questions about the evidence in the case. ^ When an expert witness or the judge (either alone or in combination with one of the attorneys) informed jurors about the Guide, the jurors voted to convict defendants likely to be guilty and to acquit defendants likely to be innocent more often than did uninformed jurors assigned to a control group. These data suggest that informing jurors about the NIJ Guide using expert testimony or instructions from a judge will improve the quality and accuracy of jurors' verdict decisions in cases involving eyewitness identification evidence. However, more research is needed to determine whether the judge will remain an effective source of information about the Guide in a longer, more detailed trial scenario and to learn more about the underlying psychological processes governing the effects observed in this experiment. ^

Age differences and conformity in juror decision -making

The purpose of this experiment was to investigate whether older adults conform more than young and middle-aged adults on a juror decision making task. Degree of group pressure, personality characteristics, gender, and social influence processes were also examined.^ Registered voters (208 participants) completed a personality questionnaire. Several weeks later, groups of six participants listened to a robbery case that portrayed the defendant as guilty. Afterwards, participants completed the first of two ballots. On the first, participants rated the defendant's degree of guilt and scored their degree of certainty in this verdict rating. They also indicated in writing which piece of information (a statement of evidence) from the robbery case supported their verdict ratings. Next, participants reviewed photocopies of five contrived first ballots. Then participants completed second ballots, in which they again rated the defendant's degree of guilt and scored their degree of certainty in this verdict rating. Finally, participants rated the importance of the five contrived first ballot verdict ratings (normative social influence) and statements of evidence (informational social influence) in reaching their second ballot verdict ratings.^ The results demonstrated that not only did older adults conform as expected, but all age groups conformed; that is, all age groups changed their verdict ratings. After reviewing the other jurors' contrived first ballots (group pressure), participants rated the defendant as less guilty on their second ballot than on their first. However, only older adults significantly changed their level of certainty in their verdict ratings from first to second ballot compared to young and middle-aged adults. With regard to personality characteristics, only rigidity predicted conformity in young and middle-aged adults but not in older adults. It was also found that females conformed more than males. Finally, all three age groups reported that different social influence processes (normative vs. informational) were important in reaching their second ballot verdict ratings. The results of this research indicate that various factors can influence young, middle-aged, and older adults as they reach verdicts. Knowledge of these factors may help alter stereotypes of older adults in terms of conformity, rigidity, and desirability as jurors. ^

The differential effects of *American and British trial proceedings on juror decision-making

Seven basic elements differentiate British from American trial procedures: confining attorneys to their tables; dealing with objections outside the presence of the jury; resolving disagreements between attorneys prior to objections being made; presenting the defense opening statement at the close of the prosecution case; the judge directly questions witnesses and has a wider latitude in controlling the evidence; and the judge gives a summation of all the evidence presented to the jury (Fulero & Turner, 1997). The present experiment examined the influence of these different courtroom procedures, judges' non-verbal behavior, and evidence strength on juror decision-making. Using models of persuasion to understand how the varying elements may effect juror decision-making, it was predicted that trials following American courtroom procedures would be more distracting for jurors and as such, they would be more likely to rely on the peripheral cue of the judge's expectations for trial outcome as expressed in his nonverbal behavior. In trials following British procedures jurors should be less distracted and better able to scrutinize the strength of the evidence that in turn should minimize the influence of the judge's nonverbal behavior. Two hundred forty-five participants viewed a mock civil trial in which courtroom procedure, judge's nonverbal behavior, and evidence strength were varied. Analyses suggest that courtroom procedure and evidence strength influenced the direction of participants' verdicts, but that judge's nonverbal behavior did not have a direct impact on verdict preference. Judge's nonverbal behavior appeared to influence other measures related to verdict. Participants were more confident in their verdicts when they agreed with judge's nonverbal behavior and when they viewed British courtroom procedures. Participants were more likely to return estimates of the defendant's liability that reflected judge's nonverbal behavior and a congruency with evidence strength. Participants also recalled more facts in the British conditions than in the American conditions. These findings are interpreted as indicating the importance of the impact of trial procedures and of nonverbal influence. ^

Twelve certain men: The impact of emotional appraisals on juror decision-making

Our jury system is predicated upon the expectation that jurors engage in systematic processing when considering evidence and making decisions. They are instructed to interpret facts and apply the appropriate law in a fair, dispassionate manner, free of all bias, including that of emotion. However, emotions containing an element of certainty (e.g., anger and happiness, which require little cognitive effort in determining their source) can often lead people to engage in superficial, heuristic-based processing. Compare this to uncertain emotions (e.g., hope and fear, which require people to seek out explanations for their emotional arousal), which instead has the potential to lead them to engage in deeper, more systematic processing. The purpose of the current research is in part to confirm past research (Tiedens & Linton, 2001; Semmler & Brewer, 2002) that uncertain emotions (like fear) can influence decision-making towards a more systematic style of processing, whereas more certain emotional states (like anger) will lead to a more heuristic style of processing. Studies One, Two, and Three build upon this prior research with the goal of improving methodological rigor through the use of film clips to reliably induce emotions, with awareness of testimonial details serving as measures of processing style. The ultimate objective of the current research was to explore this effect in Study Four by inducing either fear, anger, or neutral emotion in mock jurors, half of whom then followed along with a trial transcript featuring eight testimonial inconsistencies, while the other participants followed along with an error-free version of the same transcript. Overall rates of detection for these inconsistencies was expected to be higher for the uncertain/fearful participants due to their more effortful processing compared to certain/angry participants. These expectations were not fulfilled, with significant main effects only for the transcript version (with or without inconsistencies) on overall inconsistency detection rates. There are a number of plausible explanations for these results, so further investigation is needed.

Twelve Certain Men: The Impact of Emotional Appraisals on Juror Decision-Making

Our jury system is predicated upon the expectation that jurors engage in systematic processing when considering evidence and making decisions. They are instructed to interpret facts and apply the appropriate law in a fair, dispassionate manner, free of all bias, including that of emotion. However, emotions containing an element of certainty (e.g., anger and happiness, which require little cognitive effort in determining their source) can often lead people to engage in superficial, heuristic-based processing. Compare this to uncertain emotions (e.g., hope and fear, which require people to seek out explanations for their emotional arousal), which instead has the potential to lead them to engage in deeper, more systematic processing. The purpose of the current research is in part to confirm past research (Tiedens & Linton, 2001; Semmler & Brewer, 2002) that uncertain emotions (like fear) can influence decision-making towards a more systematic style of processing, whereas more certain emotional states (like anger) will lead to a more heuristic style of processing. Studies One, Two, and Three build upon this prior research with the goal of improving methodological rigor through the use of film clips to reliably induce emotions, with awareness of testimonial details serving as measures of processing style. The ultimate objective of the current research was to explore this effect in Study Four by inducing either fear, anger, or neutral emotion in mock jurors, half of whom then followed along with a trial transcript featuring eight testimonial inconsistencies, while the other participants followed along with an error-free version of the same transcript. Overall rates of detection for these inconsistencies was expected to be higher for the uncertain/fearful participants due to their more effortful processing compared to certain/angry participants. These expectations were not fulfilled, with significant main effects only for the transcript version (with or without inconsistencies) on overall inconsistency detection rates. There are a number of plausible explanations for these results, so further investigation is needed.

Improving civil jury decision-making: Evidentiary and procedural issues

The civil jury has been under attack in recent years for being unreliable and incompetent. Considering the myriad causes for poor civil juror decision-making, the current investigation explores both procedural and evidentiary issues that impact juror's decisions. Specifically, the first phase of this dissertation examines how jurors (mis)use evidence pertaining to the litigants when determining liability and awarding damages. After investigating how jurors utilize evidence, the focus shifts to exploring the utility of procedural reforms designed to improve decision-making (specifically revising the instructions on the laws in the case and bifurcating the damage phases of the trial). Using the results from the first two phases of the research, the final study involves manipulating pieces of evidence related to the litigants while exploring the effects that revising the judicial instructions have on the utilization of evidence in particular and on decision-making in general. ^ This dissertation was run on-line, allowing participants to access the study materials at their convenience. After giving consent, participants read the scenario of a fictitious product liability case with the litigant manipulations incorporated into the summary. Participants answered several attitudinal, case-specific, and comprehension questions, and were instructed to find in favor of one side and award any damages they felt warranted. Exploratory factor analyses, Probit and linear regressions, and path analyses were used to analyze the data (M-plus and SPSS were the software packages used to conduct the analyses). Results indicated that misuse of evidence was fairly frequent, though the mock jurors also utilized evidence appropriately. Although the results did not support bifurcation as a viable procedural reform, revising the judicial instructions did significantly increase comprehension rates. Trends in the data suggested that better decision-making occurred when the revised instructions were used, thus providing empirical support for this procedural reform as a means of improving civil jury decision-making. Implications for actual trials and attorneys are discussed. ^