I’ve been meaning to post for a while about an article from Richard Dawkins’ new book A Devil’s Chaplain. In it he disparages (and misunderstands the reasons for) trial by jury, but in the end he comes up with an intriguing suggestion for reform. An online version of the article is available here.

Dawkins assumes that the purpose of a jury is strictly to determine the factual issue of guilt or innocence by polling the decisions of its members. He compares the process to an esoteric scientific experiment to test innate color preference in herring gulls and asks what conditions need to be met to return valid results. Answer: there must be a large sample and each individual in it must be tested independently. Testing one bird doesn’t tell you anything meaningful about the species; testing a bunch of birds in a group introduces the possibility of imitative tendencies spoiling the data. Getting good results requires testing lots of birds individually.

So how do our human juries stack up against the herring gulls? Twelve people evaluating the evidence is better than relying on a single judge, but the evaluations aren’t truly independent. As Dawkins notes:

…juries are massively swayed by one or two vocal individuals. There is also strong pressure to conform to a unanimous verdict, which further undermines the principle of independent data. Increasing the number of jurors doesn’t help, or not much (and not at all in strict principle). What you have to increase is the number of independent verdict-reaching units.

What to do? Having multiple twelve person juries would be prohibitively expensive and complete isolation for each juror would remove the benefits that arise from group deliberation. Dawkins suggests that the system could be improved by having two juries of six people, or three of four, at every trial. They would be completely sequestered and would all have to reach the same verdict for an outcome to be valid. He calls this the Two Verdict Concordance Test and it would allow us to say with more confidence that cases that pass it have truly been proven beyond a reasonable doubt.

Up to this point I agree with Dawkins (more on that in a minute), but at the next step his view of trial by jury as strictly a fact finding tool takes his argument in a bad direction. He proposes testing trial by two juries against trial by two judges. Whichever system yields the higher concordance must be the more reliable system and, therefore, the one we should adopt. Dawkins places his bet with the judges:

Would you bet on two independent juries reaching the same verdict in the Louise Woodward case? Could you imagine even one other jury reaching the same verdict in the O.J.Simpson case? Two judges, on the other hand, seem to me rather likely to score well on the concordance test. And should I be charged with a serious crime here’s how I want to be tried. If I know myself to be guilty, I’ll go with the loose cannon of a jury, the more ignorant, prejudiced and capricious the better. But if I am innocent, and the ideal of multiple independent decision-takers is unavailable, please give me a judge.

But what if he was factually guilty of breaking an unjust law (say, one that prohibits teaching evolution in school)? That Dawkins does not say, and therein lies the problem.

Dawkins writes that, “Twelve jurors are preferred to one judge only because they are more numerous.” Not so. Jurors are also preferred to judges because they represent the community, not the state. Statistical validity was not the concern of religious and political dissidents suppressed by the Court of Star Chamber, or pamphleteers charged with sedition in Colonial America, or abolitionists illegally aiding escaped slaves after the passage of the Fugitive Slave Act. Though underappreciated today, the power and right of juries to refuse to convict in unjust circumstances was vital for winning some of our most cherished freedoms.

There is still a role for jury nullification in modern life, such as in trials dealing with medical marijuana, euthanasia, regulation, taxation, or just cases where a law that’s good in general is bad in a particular case. Juries might not score as well as judges on the Two Verdict Concordance Test, especially in these kinds examples, but that is a feature of the system, not a defect.

Granting that Dawkins misses this point, does the rest of his analysis hold up? I think it does. Fact finding isn’t the only function of a jury, but it is one function. Even when the less objective, “conscience of the community�” role of the jury is taken into account a representative verdict is more likely to come about with multiple juries than it is with just one. The only downside I can see is that the smaller juries would be less likely to include members with relevant expertise (for instance, a psychiatrist in a case involving prescription drug use), but with the way juries are dumbed down with peremptory strikes these days that’s not likely a relevant concern.

From a libertarian point of view, multiple juries would likely have the additional benefit of increasing the prevalence of nullification. As in the present system, any one juror would still have the power to prevent conviction. However, he would face less pressure to go along with a unanimous or guilty verdict since no one in the room would know what the other juries on the case are going to decide. [Afterthought 1/5/04: Or might he be less inclined to nullify, mentally shifting responsibility to the members of the other juries?]

I don’t know if it would be constitutional for a state to amend its jury system in this way and it’s probably best not to mess unnecessarily with something as important as trial by jury. Nonetheless, if the opportunity to institute trial by multiple juries arises (the first Moon colony? Iraq?), it looks like a sound option for reform.

The rest of A Devil’s Chaplain is up to Dawkins’ usual high standard. It’s an eclectic assortment of his shorter writings, with everything from reviews of Stephen Jay Gould’s books to a letter he wrote to his then ten year old daughter on good and bad reasons for believing things to remembrances of Douglas Adams. Recommended for its elegant writing, clear thoughts about evolution, and refreshingly candid attacks on religion.

For more on jury nullification, see the excellent book Jury Nullification by Clay Conrad or, for a shorter presentation, read this paper I wrote on the subject.