The case against expert witness testimony in monkey trials

First, I will give a history of expert witness testimony in monkey trials.

The first "monkey trial," the 1925 Scopes trial, had expert witness testimony, but it was testimony on knowledge of the Bible instead of scientific testimony, and the expert witness was the prosecuting attorney, William Jennings Bryan. "Inherit the Wind", the play and movie that was loosely based on the Scopes trial, also had expert witness testimony by the prosecuting attorney.

McLean v. Arkansas Board of Education(1982), which did not get past the district court level, had a lot of expert witness testimony. In fact, there is now a project to recover as much as possible of the expert witness testimony in that case, which seems silly because this testimony is so outdated, being a quarter-century old.

Things changed radically in Edwards v. Aguillard(1987). In that case, the district court judge refused to hear a "Monday morning battle of the experts" and the Supreme Court agreed with that refusal. The majority opinion said (pages 595-596),

The Louisiana Legislature did hear and rely on scientific experts in passing the bill, but none of the persons making the affidavits produced by the appellants participated in or contributed to the enactment of the law or its implementation. The District Court, in its discretion, properly concluded that a Monday morning "battle of the experts" over possible technical meanings of terms in the statute would not illuminate the contemporaneous purpose of the Louisiana Legislature when it made the law.

Note the emphasis on the words "properly concluded" -- some people don't seem to understand that a statement of agreement with a lower court's decision is quite a bit different from merely saying that a lower court did not abuse its discretion.

Unfortunately, the courts in later cases did not follow Edwards' lead of refusing to hear the testimony of expert witnesses who had played no part in directly influencing the government policies where such testimony was arguably not necessary for deciding the case. There was a little expert witness testimony in the Selman v. Cobb County evolution-disclaimer textbook sticker case, but it was not a significant factor in the decision, and one of the reasons for that is that the sticker did not specifically identify any criticism of evolution. However, as everyone knows, expert witness testimony was a major part of the Kitzmiller v. Dover trial, taking about half of the six-week trial. The expert witnesses added considerably to the expense of the trial -- there was not only the courtroom testimony but also depositions to be heard and expert reports to be read. There was really no reason for the depositions because all of the expert witnesses had big paper trails of publications. Eighty-five scientists submitted an amicus brief urging Judge Jones to not rule on the scientific merits of intelligent design. Judge Jones could have ruled against the defendants just on the basis of their religious motivations but chose instead to make a broad ruling that used the expert testimony to judge the scientific merits of irreducible complexity and intelligent design. Also, some of the most influential "expert" testimony in Kitzmiller was not scientific testimony but was the conspiracy theories of Barbara Forrest.

Judges themselves have recognized that courts are ill-suited for deciding questions of science. In Daubert v. Merrell Dow Pharmaceuticals, 509 U.S. 579 (1993), which concerned the rules for admissibility of expert scientific testimony, the opinion of the court said,

It is true that open debate is an essential part of both legal and scientific analyses. Yet there are important differences between the quest for truth in the courtroom and the quest for truth in the laboratory. Scientific conclusions are subject to perpetual revision. Law, on the other hand, must resolve disputes finally and quickly.

And in the same case, Chief Justice Rehnquist said in an "other" (neither dissenting nor concurring) opinion --

Twenty two amicus briefs have been filed in the case, and indeed the Court's opinion contains no less than 37 citations to amicus briefs and other secondary sources.

The various briefs filed in this case are markedly different from typical briefs, in that large parts of them do not deal with decided cases or statutory language -- the sort of material we customarily interpret. Instead, they deal with definitions of scientific knowledge, scientific method, scientific validity, and peer review -- in short, matters far afield from the expertise of judges. This is not to say that such materials are not useful or even necessary in deciding how [Federal Rules of Evidence] Rule 703 should be applied; but it is to say that the unusual subject matter should cause us to proceed with great caution in deciding more than we have to, because our reach can so easily exceed our grasp.

There are some court cases -- e.g., product liability cases -- where it is absolutely essential to judge the scientific merits of ideas in order to reach a decision, but I assert that monkey trials do not fall into that category. Here are some reasons why the courts should, where possible, avoid hearing expert scientific testimony and deciding scientific questions --

(1) -- the courts have no constitutional or legal authority to decide scientific questions.

(2) -- scientific questions are outside the judges' areas of expertise.

(3) -- scientific ideas may be hurt by experts who make poor presentations (like Michael Behe's testimony that intelligent design is like astrology)

(4) -- there is often insufficient evidence for ruling on a scientific question -- the evolution v. ID controversy is a prime example!

(5) -- judgments on scientific issues are often highly subjective and arbitrary

(6) -- scientific knowledge is subject to change, which could cause court decisions to become obsolete or outdated

(7) -- in establishment clause cases, expert testimony often does not illuminate the purposes of the government or the perceptions of the local community, i.e., this testimony is a "Monday morning battle of the experts"

(8) -- rejections by the courts stigmatize struggling scientific ideas and make it even harder for those ideas to gain acceptance. Thus, rulings on scientific merits can even impede scientific progress.

(9) -- it is possible for something to have no scientific merit and yet not be considered to be a religious concept -- atrology and alchemy are good examples. There is no constitutional separation of bogus science and state

(10) -- many scientific questions are highly contentious issues, and the answers to many scientific questions should just be matters of personal opinion