Crazy Court Cases Show: Bad Science Makes Bad Law

A court once determined that dropping a can of orange juice can cause breast cancer.1

In another court, an “expert” witness testified that breast implants cause drunk driving — even in persons who have had their implants removed.2

A conflict is growing between science and law: a conflict that threatens to undermine the effectiveness of both.

The conflict arises because trial lawyers, increasingly beguiled by the possibility of multi-million dollar paydays (as enjoyed by some lawyers in the field of asbestos and silicon implant litigation), are all-too-frequently paying “hired gun” scientific experts to testify in court.

These experts are hired to testify according to what the lawyer needs them to say, not necessarily to provable scientific truth. The result of this abuse and others is a litigation crisis that is costing American consumers over $150 billion annually,3 adding 2.5% to the cost of the average new product in America.4 Furthermore, as the United States is a nation built on the twin pillars of the rule of law and the importance of scientific advancement and industriousness, this discord undermines respect for two concepts that are key to what it means to be an American.

Fortunately, two major U.S. institutions — the U.S. Supreme Court and the American Medical Association — have begun to address this critical problem.

Expert Testimony and the U.S. Supreme Court

The U.S. Supreme Court in recent years has taken several significant steps toward the promotion of sound science in the courtroom. In the 1997 case of General Electric Co. v. Joiner and the 1993 case of Daubert v. Merrell Dow Pharmaceuticals, the court upheld a judge’s right to determine the admissibility of scientific evidence in his courtroom.

The Supreme Court ruled that under Federal Rule of Evidence 702,5 court judges can exclude improper scientific expert testimony. The Court further specified that, in examining the admissibility of scientific testimony, courts should consider if the scientific evidence has been or can be tested; if it has been peer-reviewed or published; if the error rate of the theory or technique is known and determine the quality of the standards in use during the testing or operation of the theory or technique in question.6

In Daubert, writing for a unanimous majority, Justice Harry Blackmun wrote: “The rules of evidence… do assign the trial judge the task of ensuring that an expert’s testimony both rests on a reliable foundation and is relevant to the task at hand.”7

In Joiner, the court also endorsed the practice of trial judges using independent experts to help them determine the soundness of the theories of trial lawyers’ scientific witnesses. In his opinion concurring with the majority, Justice Stephen Breyer quoted approvingly from an amici brief filed in the case by the New England Journal of Medicine:

[A] judge could better fulfill this gatekeeper function if he or she had help from scientists. Judges should be strongly encouraged to make greater use of their inherent authority… to appoint experts… Reputable experts could be recommended to courts by established scientific organizations, such as the National Academy of Sciences or the American Association for the Advancement of Science.8

Speaking in February 1998 before the American Association for the Advancement of Science, Justice Breyer advanced this argument in significantly more detail, saying in part:

Our Court recently made clear that the law imposes upon trial judges the duty, in respect to scientific evidence, to become evidentiary “gatekeepers.” The judge, without interfering with the jury’s role as trier of fact, must determine whether purported scientific evidence is “reliable” and will “assist the trier of fact,” thereby keeping from juries testimony that [is wrong]. Trial judges, looking for ways better to perform this function, increasingly have used pretrial conferences to narrow the scientific issues in dispute, pretrial hearings where potential experts are subject to examination by the court, and the appointment of specially trained “law clerks” or scientific “special masters.”

Judge Weinstein, for example, suggests that courts sometimes “go beyond the experts proferred by the parties” and “appoint independent experts” as the federal Rules of Evidence allow. Judge Reavely points out that two hundred years ago Lord Mansfield would sit with two experts next to him on the bench to explain technical commercial terms and practices. Judge Rosen recently appointed a University of Michigan Medical School professor to testify as an expert witness for the court, helping to determine the relevant fact in a case challenging a Michigan law prohibiting partial birth abortions. Judge Stearns, acting with the consent of the parties, in a recent highly technical genetic-engineering patent case appointed a Harvard Medical School professor, as the “court’s technical advisor.” In a written agreement with the court, the “advisor” promised to serve “as a sounding board for the court to think through the scientific significance of the evidence” and to “assist the court in determining the validity of any scientific evidence, hypothesis or theory on which the experts base their testimony.”

These techniques are neutral, in principle favoring neither plaintiffs nor defendants. When used, they have typically proved successful. Judge Stearns, for example, found that working with a well-qualified technical expert serving as an advisor in a role akin to that of a law clerk, was an extremely helpful way to understand, and thereby better to deal with, the technical claims of the parties in a highly technical case. Many of those, perhaps all of those, involved in the Michigan case concluded that the judge’s use of an independent expert enhanced both the credibility and the objectivity of the legal process.

Nonetheless, judges have not often invoked their Rules-provided authority to appoint their own experts. They may hesitate simply because the process is unfamiliar, or because the use of this kind of technique inevitably raises questions. Will use of an independent expert, in effect, substitute that expert’s judgment for that of the court? Will it inappropriately deprive the parties of control over the presentation of the case? Will it improperly intrude upon the proper function of the jury? Where is one to find a truly neutral expert? Will it create inordinate delay or significantly increase costs? Who will pay the expert? Judge Acker writes:

Unless and until there is a national register of experts on various subjects and a method by which they can be fairly compensated, the federal amateurs wearing black robes will have to overlook their new gatekeeping function lest they assume the intolerable burden of becoming experts themselves in every discipline known to the physical and social sciences, and some as yet unknown but sure to blossom.

It is fortunate that this Association, working with the American Bar Association and Federal Judicial Center, has begun to explore these matters with an eye toward finding practical ways to provide scientific help. The AAAS has helped develop a pilot project, just recently getting underway, to test the feasibility of increased use of court appointed experts in cases that present technical issues. The project, aimed at both civil and criminal litigation, will provide a slate of candidates to serve as court-appointed experts in cases in which the court has determined that the traditional means of clarifying issues under the adversarial system are unlikely to yield the information that is necessary for a reasoned and principled resolution of the disputed issues.

The project might also examine in some detail instances in which courts have successfully used their own outside experts. How were those experts identified? How might this better be done? How did the court, while protecting the interests of the lawyers and the parties they represent, also protect the experts from unreasonable demands, say on their time? How did the court prepare the expert to encounter what may be an unfamiliar and sometimes hostile legal environment? How might this better be done?

The project might also ask whether criteria emerge that help to determine when a court-appointed expert will prove useful and whether that expert might better serve in an advisor-type or in a witness-like capacity. It would undoubtedly also be helpful to recommend methods for educating efficiently (i.e., in a few hours) willing scientists in the ways of the courts just as it is helpful to develop those kinds of training that might better equip judges to understand the ways of science.

To answer some of these or related questions will help determine the practicality of what seem promising methods to help bring science and law closer together. There may be others. As FDR said many years ago, “it is common sense to take a method and try it. If it fails, admit it frankly and try another. But, above all, try…”

I conclude where I began. I believe that in this age of science we must build legal foundations that are sound in science, as well as in law. You have offered your help. We in the legal community should accept that offer, and we are in the process of doing so. The result, in my view, will further not only the interests of truth, but also those of justice. The law will work better to resolve many of the most important human problems of our time.”9

This November, the Supreme Court will hear arguments in the case of Kumho Tire Co. Ltd. V. Carmichael, a case about an alleged tire defect, to determine if a court’s right to determine the admissibility of expert testimony applies to technical as well as scientific expertise.


Expert Testimony and the American Medical Association

Increasingly concerned about the impact of false or misleading medical testimony on patient care and on the credibility of the medical profession, the American Medical Association (AMA) in December 1997 decided to include the act of giving courtroom medical expert testimony as part of the official practice of medicine.

This is an important determination, because it brings the act of providing medical expert testimony under peer review. In other words, when a doctor testifies in court as an expert witness his opinion is subject to evaluation by other qualified doctors. If the doctor providing expert scientific testimony is found by his peers to have testified falsely or misleadingly, he can be sanctioned or even lose his license to practice medicine.

Dr. David M. Priver, immediate past president of the San Diego County Medical Society, explains why this change is necessary:

A physician who treated a patient in a diabetic coma with glucose — sugar — not only would have his or her patient die. That physician almost certainly would be severely disciplined through the peer review process.

However, if that same physician testified as an expert witness that the appropriate treatment for diabetic coma was glucose, until now there would be no disciplinary mechanism to punish the doctor and protect the integrity of the court system.10

The AMA’s policy on expert physician testimony is clear. According to a 1998 report of the AMA Board of Trustees, the policy states:

As a citizen and as a professional with special training and experience, the physician has an ethical obligation to assist with the administration of justice,

The medical witness must not become an advocate or a partisan in the legal proceeding,

The medical witness should be adequately prepared and should testify honestly and truthfully,

The attorney for the party who calls the physician as a witness should be informed of all favorable and unfavorable information developed by the physician’s evaluation of the case, and

It is unethical for a physician to accept compensation that is contingent upon the outcome of the litigation.11

The AMA Board of Trustees report also expresses concern about the current situation with regard to physicians serving as expert witnesses in court proceedings:

Some expert witnesses develop theories of medicine or causation that are not sufficiently grounded in medical science. Generally, there is an economic incentive to do so. Income derived from expert witness testimony can be substantial. Although the AMA has deemed it unethical, fees can be earned on a contingency basis where the expert or “consulting firm” he or she works for earns more if the case is won. Economic incentives can color the nature of the physician expert’s testimony.

Despite ethical guidelines and judicial discretion to exclude testimony that is not scientifically valid, “junk science” still finds its way into court through unchecked testimony of physicians. Examples abound regarding the continued problems of false and/or misleading physician testimony. A recent article, “Irresponsible Testimony by Medical Experts in Cases Involving the Physical Abuse and Neglect of Children,” written by Drs. David L. Chadwick and Henry F. Krous, demonstrates that physicians as professionals have tremendous responsibilities, as do the trial judges, to ensure that scientifically valid information is considered in the judicial process. The article presents several examples wherein physicians misquoted standard journals and texts, made false statements, and deliberately omitted important facts and knowledge as it pertained to the expert opinion offered. Physicians who engage in such conduct lead to poor decision-making by our judges and juries. Expert witness testimony should be an objective resource to these persons.12

The AMA estimates that physicians testify as expert witnesses in nearly half of all federal civil trials, making physicians the largest group of expert witnesses.13


The growing antagonism between science and the law, brought on by a handful of trial attorneys and paid expert witnesses, undermines respect for both law and science. Efforts by the court system to weed out unreliable scientific testimony and by the American Medical Association to sanction physicians who testify falsely should help correct a litigation crisis that costs American consumers hundreds of billions of dollars each year.

Science and the law are interdependent. As Supreme Court Justice Stephen G. Breyer has said, “The practice of science depends upon sound law… It is equally true, that the law itself increasingly needs access to sound science.”14


Amy Ridenour is president of The National Center for Public Policy Research. Comments may be sent to [email protected].



1 “The Interdependence of Science and Law,” Associate Justice Stephen G. Breyer, Supreme Court of the United States, Address at the 1998 American Association for the Advancement of Science Annual Meeting and Science Innovation Exposition, Philadelphia, Pennsylvania, February 16, 1998

2 “Junk Science Redux,” Wall Street Journal Editorial, November 22, 1996

3 “Improving the American Legal System: The Economic Benefits of Tort Reform,” Study, Joint Economic Committee of the U.S. Congress, March 1996

4 “The Case for Legal Reform,” Speech by U.S. Senator Spencer Abraham, published by the California Association for Legal Reform

5 Rule 702 reads: “If scientific, technical or other specialized knowledge will assist the trier of fact to understand the evidence or determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education, may testify thereto in the form of an opinion or otherwise.”

6 “Kumho Tire v. Carmichael and the District Court’s Role as Gatekeeper for Non-Scientific Expert Testimony,” by David E. Bernstein, Associate Professor, George Mason School of Law, Vienna, Virginia, Draft of September 16, 1998

7 Justice Harry Blackmun, Majority Opinion, Daubert v. Merrell Dow Pharmaceuticals, U.S. Supreme Court, June 28, 1993

8 Justice Stephen Breyer, Opinion Concurring with the Majority, General Electric Company v. Joiner, December 15, 1997

9 “The Interdependence of Science and Law,” Associate Justice Stephen G. Breyer, Supreme Court of the United States, Address at the 1998 American Association for the Advancement of Science Annual Meeting and Science Innovation Exposition, Philadelphia, Pennsylvania, February 16, 1998

10 “Doctors Will Combat Junk Science Experts,” by Dr. David M. Priver, Charlotte Observer, March 6, 1998

11 American Medical Association, Report of the Board of Trustees, Report 5-A-98, 1998

12 American Medical Association, Report of the Board of Trustees, Report 5-A-98, 1998

13 American Medical Association, Report of the Board of Trustees, Report 5-A-98, 1998

14 “The Interdependence of Science and Law,” Associate Justice Stephen G. Breyer, Supreme Court of the United States, Address at the 1998 American Association for the Advancement of Science Annual Meeting and Science Innovation Exposition, Philadelphia, Pennsylvania, February 16, 1998

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