In a Reason article recounting his recent jury service, Matt Welch describes how lawyers worked to exclude jurors with knowledge relevant to the assessment of medical evidence at stake in the case:

The Court Street lawyer in my civil case, who dominated the jury-selection proceedings (as plaintiff’s counsel often does), practically came out of his chair whenever any prospective juror so much as copped to having a relative in the medical industry. He was very anxious about whether they had heard of obscure medical terminology related to the injured body-part in question, and wondered whether people would be able to handle the dissonance of medical professionals disagreeing with one another.

Such practices are well-known to legal professionals. When my wife was recently called for jury service in a federal court, we were confident she would never actually be empaneled to decide a case, especially one involving criminal justice issues, or antidiscrimination law. Why? Because she works for the US Commission on Civil Rights and has considerable expertise on these issues. One side or the other would likely view her as a threat to their cause, and try to exclude her.

Welch cites an earlier article by Walter Olson, who points out that exclusion of more knowledgeable jurors is a standard tactic:

[A] major goal of the selection process is the removal of any jurors with too strong a base of experience, knowledge, or opinion about the case’s subject matter. If a case presents important medical or accounting issues, for example, lawyers on one or both sides probably will want to get rid of jurors with expertise in those areas…

Manuals emphasize the importance of excluding potential “opinion leaders” for the other side. “You don’t want smart people,” says a Philadelphia prosecutor in an old training tape. “[They’ll] analyze the hell out of your case.”

While juror ignorance is not as severe a problem as voter ignorance, it is nonetheless troublesome in cases involving scientific evidence and other complex issues – precisely the sorts of cases where the exclusion of those with specialized knowledge is most likely to occur, and most likely to cause harm.

Admittedly, there are cases where knowledge can actually cause more harm than good. A little knowledge can be a dangerous thing when a juror knows a small bit about some complex issue relevant to a case, and overvalues the significance of that information. Such misleading bits of knowledge can potentially be worse than complete ignorance, especially if the completely ignorant person is aware of his ignorance and careful about drawing conclusions as a result. In general, however, a juror with relevant knowledge and expertise is likely to do a better job of assessing complex evidence than one who lacks such a background.

Concerns about jury ignorance have a long history. In Democracy in America, Alexis de Tocqueville worried that “the jury system arose in the infancy of society, at a time when only simple questions of
fact were submitted to the courts; and it is no easy task to adapt it to the needs of a highly civilized nation, where the relations between men have multiplied exceedingly and have been thoughtfully elaborated in a learned manner.” More colorfully, Mark Twain complained that “[t]he jury system puts a ban upon intelligence and honesty, and a premium upon ignorance, stupidity and perjury.” Such ignorance is more of a danger in an era where jurors are often called on to assess complex scientific evidence and expert testimony.

The problem is not an easy one to solve. It is understandable that lawyers try to exclude jurors whose presence reduce their chances of winning. A lawyer who chose not to do so would be neglecting his or her duty to the client.

The most obvious solution would be to follow the example of most European nations, and abolish the use of juries altogether, or severely limit it. But that approach is, of course, precluded by rights enshrined in the federal and state constitutions. Some scholars argue that states should adopt rules making it more difficult for lawyers to strike jurors.

The problem of juror ignorance also strengthens the case for making jury service voluntary. As in the case of voters, those who choose to serve voluntarily may well be more knowledgeable than those who do so only because they are forced to. States could incentivize more knowledgeable citizens to serve on juries by compensating those who serve for the full value of their time.

Such a system need not be more costly to society than the current one, in which the costs of jury service are arbitarily imposed on those who have misfortune of being called rather than spread throughout the taxpaying public. Moreover, improving the quality of jury decision-making might well be worth some increase in expenditures, if it were necessary.

These and other potential solutions are not mutually exclusive. Perhaps we should simultaneously make it harder for lawyers to exclude jurors based on their knowledge and make jury service voluntary.