On what basis is an expert witness judged by a jury?

Dr. Manges Ph.D. | Forensic Psychologist | Expert Witness

“Because one believes in oneself, one doesn’t try to convince others. Because one is content with oneself, one doesn’t need others’ approval. Because one accepts oneself, the whole world accepts him or her.” – Lao Tzu

Although the expert is there to testify so the jury will make a decision about a plaintiff or a defendant, another person “on trial” is the expert. The expert, whether in Ohio, Florida, New York, Texas or Illinois, is being considered by the viewing and listening jury member and judged as to their believability.

Schuman et.al. In the Jurimetrics Journal found that jurors judged an expert on six basic tenants.

  1. Their tendency to draw a FIRM conclusion.
  2. Their qualifications
  3. Their reputation
  4. Their reasoning
  5. Their familiarity with the facts
  6. Their impartiality

Interestingly and somewhat inconsistent with other studies Schuman et. al found the jurors did not rely on appearance, personality or to defer automatically to an expert’s conclusions.

In another study by Ivkovich et.al. in a smaller study of 55 jurors, they found the jurors relied on:

  1. The expert’s completeness, consistency with other experts and complexity.
  2. These same jurors ranked experts based on their credentials, motives for testifying, general impressions, and a combination of the expert’s content and presentation.

Overall, experts who were found to be good teachers without prejudice and sound credentials were ranked most favorably.