What Jurors Look For In An Expert Witness
By Paul Luvera
Modern jury research suggests that today’s jurors are increasingly skeptical of authority figures and experts. As a result, authenticity may matter as much as credentials. Jurors are generally persuaded by experts who appear genuine, candid, and interested in helping the jury understand the evidence.
The same is not true of experts who simply recite their résumé. Jurors are laypersons. Experts who explain complex concepts in plain language are rated as more credible and persuasive than highly technical experts who lecture or overwhelm the jury. This confirms the fact that communication skills matter more than academic education.
However, education, experience, and professional accomplishments do matter to jurors. That’s particularly true when they directly relate to the issue in dispute. But credentials alone do not determine credibility. That’s because jurors evaluate expert testimony by whether the expert actually knows what they are talking about.
The overall evaluation of expert testimony by jurors was reviewed in the National Institute of Justice study “Important Traits That Enhance Expert Witness Credibility.” It noted that extensive observation of expert witness testimony in numerous actual trial settings found credible expert testimony included these factors:
(1) Knowledge of the specialty area;
(2) Ability to translate the complex into the simple;
(3) Open-handed honesty, even to the extent of admitting fallibility or possibility of error;
(4) History of solving similar problems in the past, both actual and theoretical; and
(5) Creative preparation of models, charts, drawings, and demonstrations.
IMS Legal Strategies, a national litigation consulting firm, published an article “What Makes Your Expert Witness the Best Witness? Social Science Research Highlights.” It reported that credibility is the foundational element that enables experts to successfully persuade jurors. It suggested an expert’s demeanor on the stand influences jurors’ evaluation of trustworthiness. This includes nonverbal cues that are indicative of honesty or dishonesty. As an example, one study found that an expert witness’s ability to maintain eye contact with both the attorneys and jurors was predictive of credibility ratings.
Research studies in legal psychology and trial advocacy, such as the Witness Credibility Model (WCM) and jury surveys, indicate that the quality of expert testimony in civil trials hinges primarily on these factors:
(1) Communication ability
(2) Perceived trustworthiness
(3) Knowledge & credentials
The and the and other research sources offer analyses on how expert demeanor translates into successful jury verdicts. These have shown that outstanding experts act as “teachers” rather than just dispensers of information. They translate complex technical, scientific, or medical concepts into accessible, layperson-friendly language without sounding condescending. Effective testimony uses anecdotes and visual illustrations (like charts, graphs, and models) to anchor and clarify their methodology.
Research on juror psychology shows that potential jurors generally rank physicians and scientific experts as highly believable. However, if testimony involves complex statistical models or raw contingency tables (e.g., in toxic tort cases), jurors often have substantial difficulty determining causation and liability, even after expert explanation. Understanding expert testimony is a primary requirement.
Jurors are highly alert for bias. Outstanding experts maintain a neutral, objective stance rather than appearing to be a “hired gun.” Experts who actively practice in their field and take on cases for both plaintiffs and defendants are viewed as more trustworthy than those whose majority of testimony is for one side.
The most effective experts remain calm, articulate, and non-defensive during aggressive cross-examination. They view attacks on their testimony as opportunities to educate the jury further. Outstanding witnesses control the tempo of their questioning by pausing before answering, taking time to explain, and refusing to be rushed by opposing counsel into giving incomplete, out-of-context answers.
While flashy credentials matter less than communication skills, jurors still need to know if the expert has reliably applied recognized methods and solid data to the specific facts of your case. Jurors highly value experts who are willing to draw firm, evidence-backed conclusions rather than speaking in vague theoretical probabilities.
IMS Legal Strategies article, “How Do Jurors View the Role of an Expert Witness?” notes that “not all expert witnesses need to have formal advanced degrees that result in numerous initials after their names. Jurors like a witness who has worked their way up the professional ladder to achieve a prestigious position or has the hands-on experience needed to possess first-hand knowledge of the subject matter.”
Jurors tend to view the experience-based expert as being like themselves; because the majority of jurors do not hold advanced degrees but do have years of experience in their jobs, they often hold a similarly situated expert in high regard.
The success of expert testimony depends not on what was said but on what the jurors understood. This is more true than any other type of testimony. Expert testimony requires clarity, simplicity, and credibility to be successful. Both verbal and nonverbal qualities determine the trustworthiness of expert testimony. Knowing what qualities are required for persuasion is essential for trial lawyers in selecting and preparing expert witnesses for trial.
Paul Luvera is the retired founder of the Luvera Law Firm. He is past president of the Washington Trial Lawyers Association and a fellow of the American College of Trial Lawyers. He can be contacted at paul@luvera.org.
