Chapter 9
| Jurisdiction | United States |
Chapter 9 Expert Examination That Persuades
An expert knows all the answers—if you ask the right questions.
A jury of laypersons cannot be converted into geniuses who will understand complicated medicine or engineering or science. It is the lawyer's job to present expert testimony so that the jury can both understand and be persuaded. How? In previous chapters, the subject of attention was explored in terms of timing, interest, curiosity, and cognitive capacity. Expert direct examination must also establish credibility and provide a framework for comprehension.
The law of evidence allows a person with special knowledge, skill, experience, training, and education to explain and describe a specialized or unfamiliar subject, then render an opinion if the subject matter is sufficiently beyond common experience that the opinion of an expert would assist the trier of fact. (See, e.g., Fed. Rules Evid., rule 702.) The expert's testimony must include the reasons for the opinion. Sounds simple, right? What could possibly go wrong? The problem with competent expert testimony isn't that it fails to adequately address the issues; the problem is that jurors either can't understand it, don't care about it, or are inclined to reject it.
The Starting Point
Twelve people are gathered together in chairs that are set up in a semi-enclosed space. They have one thing in common: they are adults who either vote or hold driver's licenses, which are two of the sources from which jury commissioners can identify potentially eligible jurors. They possess widely varying levels of education and sophistication. They are usually not doctors or scientists. These folks will be asked to make a decision about your case. Usually, before the decision has to be made, they will have heard experts give explanations and render opinions. Then, the judge reads them an instruction like this:
As with any other witness, it is up to you to decide whether you believe the expert's testimony and choose to use it as a basis for your decision. You may believe all, part, or none of an expert's testimony. In deciding whether to believe an expert's testimony, you should consider:
a. The expert's training and experience;
b. The facts the expert relied on; and
c. The reasons for the expert's opinion.
Of course, both sides have introduced expert testimony and, nearly always, the experts have rendered opinions that are diametrically opposed to each other. The defendant did/did not breach the standard of care. The event did/did not cause harm. The judge will further instruct the jury:
If the expert witnesses disagreed with one another, you should weigh each opinion against the others. You should examine the reasons given for each opinion and the facts or other matters that each witness relied on. You may also compare the experts' qualifications.
The Problem
If jurors have no subject matter experience in medicine, science, or biomechanics, how can they possibly decide which expert opinion to believe? Before they became jurors, these citizens lived normal lives where they frequently made decisions about unfamiliar things. When shopping for breakfast cereal, soup, or cleaning products, they had to decide between competing products. When employing parenting skills, they had to accept or reject advice, such as "spare the rod, spoil the child." When competing shows are on television, they had to decide which one to watch. (Well, maybe not now, since they could use their DVR to watch one later. But they still chose what they will record and watch later.) The point is that they had to constantly make decisions and choices. And to do so, they employed common methods, such as "Which makes more sense to me?" So, their decision-making process was based on existing knowledge and relatable experience. Stated another way, they drew on something they already knew to understand something new and unfamiliar. In his book Thinking, Fast and Slow, psychologist Daniel Kahneman describes these mental shortcuts as heuristics.1 (Heuristics are discussed in more detail in chapter 12, "Mental Shortcuts and Biased Preexisting Beliefs," and chapter 13, "Overcoming Bias With Perspective and Framing.")
Case-in-point: My adult son was once employed in the field of educational video games. My understanding of this field was limited. (Actually, I didn't understand it at all; not a clue.) He was explaining to me about the process of how a third-party creator of a game gets a company to use it "on their platform," which is then packaged, sold, and marketed. I got lost when he said on their platform. So, I tried to understand it by comparing it to what I did know. I'll skip over the many questions I asked in trying to understand. (Imagine the Wright brothers' grandmother trying to understand Orville and Wilbur's description about their flying machine.) But, finally, I asked my son if it was "sort of like the process where an author sells his book to a publisher who edits it, prints it, and markets it." My son patiently explained that there was more to it, but I was satisfied that I now had a frame of reference to understand what he did for a living. (Of course, I wouldn't have had this problem if he had become a lawyer!)
My experience in trying to grapple with a new and perplexing subject by reference to what I did understand is similar to how a jury needs help to understand the unfamiliar. But before the jurors will be motivated to understand the...
To continue reading
Request your trial