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Influence Your Verdict by Changing Jurors' Perceptions of Expert Witnesses, Part Two

By Joseph M. Hanna – December 14, 2011

Part One of “Influence Your Verdict by Changing Jurors' Perceptions of Expert Witnesses” appeared in the summer 2011 issue of Minority Trial Lawyer.

Expert Characteristics: Credibility, Credentials and Motives
The “Jurors’ Evaluations of Expert Testimony” study reported that jurors’ comments about experts’ credibility could be classified into two major types: comments about personal characteristics of the expert and comments about the testimony. Sanja Kutnjak Ivkovic & Valerie P. Hans, "Jurors’ Evaluations of Expert Testimony: Judging the Messenger and the Message," 28 Law & Soc. Inquiry 457–58 (2003). In terms of personal characteristics, jurors’ comments were categorized as relating to the expert’s credentials, motives, or general impressions. Id. at 458. As for testimony, the jurors’ comments were categorized as those pertaining to the expert’s content and style.

The jurors’ associated the following characteristics with credible testimony: good credentials; lack of bias; a pleasant personality; a clear, objective, focused, not overly long presentation that utilizes diagrams and models; use of lay terms; a presentation that is complete, consistent, and not too complex; knowledgeable in the area of expertise; and familiarity with the case.

Jurors can be influenced by experts’ credentials, such as professional activity (e.g., presenting papers at conferences and seminars), their formal education, and their research activity. Id. at 461. Typically, the jurors who used credentials as the basis for their judgment of the experts’ credibility thought that the experts with good credentials were credible witnesses. Having an expert witness with a long list of credentials, however, is not an automatic guarantee of credibility. The jurors mostly mentioned credentials and used this as a factor when jurors compared the credibility of experts from the same field. Id.

Jurors can be influenced by perceived motives. Many jurors attempt to determine the motives that an expert may bring to the witness stand. Id. at 464. The jurors in the study focused primarily on characteristics that reduced an expert’s credibility, such as an expert’s potential motive for bias, the magnitude of his fees, the frequency with which he testified, and the expert’s relationship to a party.

Jurors’ General Impression of Expert Witnesses
Also instructive were jurors’ comments about expert witnesses that were outside the categories of credibility, credentials, and motive. Id. at 468. The authors called this category “general impressions of expert witnesses,” and it included comments about age (“He was an older doctor.”), gender (“the lady doctor”), nationality (“I believe he was the Irishman.”), physical appearance (“He’s a tall man with blonde hair.”), and dress of expert witnesses (“One of them wore bow ties. Which one was that?”). Other factors that were included in the general category by the authors included the expert’s personality and attitude, as well as any personal acquaintance with the expert, and jurors’ judgments about these factors did appear to influence their assessment of expert credibility. Id. at 469.

The jurors surveyed not only judged the experts as individuals but also the presentation of technical material during testimony. Jurors clearly preferred live testimony by experts over the reading of depositions. Moreover, jurors’ assessments appeared to be influenced by how experts presented their information. Id. at 470. It was noted that the jurors appreciated the use of some forms of technical aid as part of the expert’s presentation, whether it was a model, a chart, a diagram, or an x-ray. Finally, jurors found it challenging where the pace was tedious or the presentation too long. Id. at 471. The authors concluded that jurors noticed the way the testimony was given and the facts presented, and they preferred clear presentation in lay terms, paced well, not too long, given enthusiastically, and supported with technical aids. Id. at 472.

Ivkovic and Hans concluded their study by looking at how jurors remarked about the content of the testimony of the expert witness. When the jurors examined the content of the testimony, they considered many factors, such as completeness, consistency, and complexity. Id. at 477. The jurors concluded that with everything else being equal, the clearer the presentation, the better they understood the evidence.

One study noted that “when there are competent experts on both sides, and they offer contradictory or confusing opinions, jurors may resolve the differences by relying on general impressions of character and veracity.” Dennis J. Devine, “Jury Decision Making: 45 Years of Empirical Research on Deliberating Groups,” 7 Psychol. Pub. Pol’y & L. 622, 624 (2001).

The Education Factor
Saks and Wissler found that as a juror’s educational level rose, he or she was less likely to believe expert witnesses. Michael J. Saks and Roselle L. Wissler, “Legal and Psychological Bases of Expert Testimony: Surveys of the Law and Jurors,” 2 Behavioral Sci. & L. 361, 435 (1984). The authors attributed their test findings to the fact that a more educated juror was more likely to have a critical appraisal of an expert’s competence. Id. at 445.

A different study found that the more educated a mock juror is, the more likely the juror is to participate actively in deliberations and to recall evidence accurately. Reid Hastie, Inside the Jury, 137–38 (1983).

The Gender Factor
Saks and Wissler reached no clear conclusion about the relationship between juror perceptions of expert testimony and gender. See Saks and Wissler at 446. Ivkovic and Hans’s study concluded that 82 percent of male jurors compared to 64 percent of female jurors agreed that lawyers could always find a compliant expert. See Ivkovic and Hans at 453.

Other research on the juror thought process found that in solving problems, males tended to “refer to abstract and rational concepts of fairness, whereas [females] tended to refer to relationships and principles of affiliation and responsibility.” Anne Bowen Poulin. “The Jury: The Criminal Justice System’s Different Voice.” 62 U. Cin. L. Rev. 1377, 1395 (1994).

It has been reported that male jurors approach decision making with a win-lose attitude not present in female decision-making. See Hastie at 142. It was found that male jurors were more vocal about factual and legal issues, while female jurors focused more on the verdict. This same study also concluded that women were more defense-orientated than men. Id. at 128.

The Age Factor
One study did not find a strong correlation between age of the prospective juror and a tendency to believe or disbelieve expert testimony. See Saks & Wissler at 448. However, the authors observed that younger prospective jurors tended to find psychologists and psychiatrists more credible than older jurors did, while older jurors tended to believe expert witnesses more than younger jurors did.

Another study indicated that mock jurors between the ages of 34 and 57 took a more active role in the decision-making process. Jurors who were older than 57 tended to take the legal process more seriously than younger jurors did; however, they failed to recall the information as accurately. See Hastie at 142.

The Occupation Factor
In the late 1970s and early 1980s, Arthur D. Austin analyzed the role of two juries that heard complex expert evidence and arguments in the same Cleveland antitrust suit. Arthur D. Austin, “Jury Perceptions on Advocacy, a Case Study,” 8 Litigation 15 (1982). The first trial ended in a hung jury, and the second trial ended in a verdict for the defendant. Austin had attended both trials, and, at the end of each, interviewed the jurors. After interviewing the jurors and analyzing their comments, Austin’s premise was that both juries were rather skeptical of the experts from both trials. The jurors from the first trial, comprised of primarily blue-collar individuals, were quite suspicious of management. Moreover, the jurors felt that the experts were “talking down to them” and the fact that the experts’ qualification were repeated over and over again to them was “needless and tasteless self-praise.” Id. at 16.

The members of the second jury were also “blue-collar” employees; however, this group was employed in supervisory jobs. Id. at 15. The members of this jury showed more of an inclination to support a more “management-oriented perspective.” It is important to note that although Austin’s conclusions about the impact of jurors’ occupations is interesting, it relates only to the analysis of the jury and the experts from only one case.

An unrelated juror study compared and contrasted the ratings given by jurors to assess different classes of witnesses and different categories of jurors in 50 trials. David Linz and Steven Penrod, “The Use of Experts in the Courtroom” (1982) (paper presented at the annual meeting of the Academy of Criminal Justice Sciences). The jurors reported that policemen and women appearing as witnesses were the most believable, honest, likeable, confident and understandable. The study went on to note that these experts were the least likely to be discredited as opposed to the other types of witnesses.

Interestingly, another study of potential jurors’ opinions of expert witnesses found that the respondents ranked physicians, chemists, and firearms experts as the most believable, honest, and experienced type of experts, followed by accountants, psychiatrists, psychologists, and eyewitnesses. Saks and Wissler, supra. Police officers, handwriting experts, and polygraph experts were ranked the lowest. Id. at 442. It is important to note that the respondents answered hypothetical questions and did not view any of the experts on the witness stand.

An Expert’s Independent Involvement
In 1989, the American Bar Association Special Committee of Jury Comprehension conducted an in-depth study of jury decisions involving four highly complex cases—three of which included expert evidence. ABA Special Committee on Jury Comprehension, “Jury Comprehension in Complex Cases” 40, 42 (1989). The ABA committee concluded that the most believable experts had an “independent involvement” with the issue on which they were testifying. However, the jurors rejected experts who seemed to be “hired guns.” Thirty-five percent of the juror respondents stated that payment of the expert by the lawyers meant that the expert could not be trusted to be unbiased. Id.

One study explored the importance of testimony’s complexity by varying the testimony’s actual content and the strength of the experts’ credentials. Joel Cooper, Elizabeth Bennett, and Holly Sukel, “Complex Scientific Testimony: How Do Jurors Make Decisions?,” Law and Human Behavior 20: 379–94 (1996). Interestingly, the study found that the personal characteristics of the experts, such as their credentials, played an important role only when the evidence was complex and the mock jurors had a difficult time evaluating it.

These studies confirm what the authors have learned during the course of their trial careers. A skillful cross-examination coupled with exposing an expert’s bias, weak credentials, and inconsistencies in his testimony is the recipe to successfully debunking the plaintiff’s expert witness. It is well known that jurors tend to decide for the plaintiff or the defense early in the trial, with a majority of jurors making up their minds after the opening statements. With the exception of the opening statement, the cross-examination of plaintiff’s expert witness is often the first instance that the defense has to challenge the expert’s opinion.

The Decision-Making Process for Jurors
“[T]he most widely adopted approach to juror decision making process is the ‘story’ model, wherein jurors attempt to assemble the evidence into a coherent whole that is consistent with the facts of the case and makes sense given their existing knowledge.” See Devine at 624. In other words, members of the jury are more apt to gather as much information as possible from the facts of the case, the parties, and expert-witness testimony and will create a story that provides them with an understanding of what happened and why.

“Storytelling is one of the most powerful ways of communicating with other people. . . . [S]ince  the time we were babies, storytelling has been the fundamental way for us to learn about life.” Richard C. Waites, “Courtroom Psychology and Trial Advocacy,” 535–37, 535 (2003). Every story is composed of facts. Therefore, undermining the plaintiff’s “story” can be critically important for success at trial.

The story model asserts that jurors do not approach the trial with a blank slate. Rather, they utilize their past experiences to filter and understand the various pieces of evidence as the evidence is presented and to develop alternative interpretations, or “stories,” about the events that led to the dispute now on trial. Nancy Pennington and Reid Hastie, “A Cognitive Theory on Juror Decision Making: The Story Model,” 13 Cardozo L. Rev. 519, 523–24 (1991). These alternative stories are then weighed against one another to determine which one is most consistent and logical. The preferred story is then considered under the instructions about the law provided by the trial judge. Id. at 530–31.

Pulling It All Together
The story model is widely accepted as a general description of how jurors process information and reach their decisions. It has many implications that bear on juror decision making. It is important to note that the various parts of trial evidence, including the testimony of experts, are not viewed in isolation. Instead, they are integrated into “stories” derived from preexisting cognitive frameworks and from the other trial evidence, including the testimony of plaintiffs, defendants, and other witnesses.

Experts who are willing to reach a firm conclusion about the issue on which they are testifying are deemed more readily believable and add credibility to the story. However, the expert’s lack of independence in the discipline in which he or she is involved, for example, performing independent research, can raise significant credibility issues. It is important to undermine the appearance that plaintiff’s expert has the expertise and objectivity to justify the jurors’ trust. Finally, establishing that the expert’s methodology/opinions are not generally accepted in the discipline involved can be decisive at the trial level and/or appeal. The cross-examination of plaintiff’s experts should seek to capitalize on this body of information concerning jurors’ decision making and receptivity to expert testimony.

Attacking Witness’s Credentials
As noted earlier, one of the primary methods of impeaching an expert witness is to cast doubt on his or her qualifications. Demonstrating that the expert is a professional witness or potentially biased will undoubtedly cause the jury to wonder whether the witness is a “gun for hire.”

It is possible to shatter the expert’s facade by raising the inference during the cross-examination that the expert is:

  • testifying outside the scope of his or her qualifications
  • using methodology that is not generally accepted
  • giving opinions that are generally not accepted
  • giving opinions that lack independent research

There is no room for speculation or conjecture in connection with expert testimony under Frye. Indeed, speculation, surmise, and conjecture are the logical antitheses of reliable and valid premises. The “average juror” may not be able to fully appreciate subtle cross-examination concerning complex scientific principles; the juror will, however, be able to recall a concession from an expert witness that his testimony is speculative. The buzz words here are surmise, conjecture, and speculation. It should, therefore, be a primary goal of the cross-examiner to elicit from the witness that at least some component of his testimony is speculative, conjectural, uncertain, or unreliable. Whether the defense is trying the case to a jury or attempting to convince a trial court or appellate court that the expert’s testimony fails to meet Frye, simple admissions elicited from plaintiff’s experts may irrevocably debunk his testimony.

Keywords: juror perception, expert witness, expert credibility, credible testimony

Joseph M. Hanna is with Goldberg Segalla LLP in Buffalo, New York.

Copyright © 2017, American Bar Association. All rights reserved. This information or any portion thereof may not be copied or disseminated in any form or by any means or downloaded or stored in an electronic database or retrieval system without the express written consent of the American Bar Association. The views expressed in this article are those of the author(s) and do not necessarily reflect the positions or policies of the American Bar Association, the Section of Litigation, this committee, or the employer(s) of the author(s).

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