Daubert v. Merrell Dow Pharmaceuticals was a 1993 U.S. Supreme Court ruling that established the Daubert Standard, a rule of evidence determining whether the testimony of expert witnesses is admissible in a civil or criminal court case. In two other cases in the 1990s, General Electric Co. v. Joiner in 1997 and Kumho Tire Co. v. Carmichael, the Court further articulated this rule of evidence. The Daubert Standard grants the right to decide whether expert witnesses are credible to trial judges rather than to juries. It instructs judges to base their decision about the admissibility of the expert witnesses’ testimony on the scientific methodology of the research they cite and recommends criteria on which to evaluate this methodology.
The Daubert case was a product liability case alleging that a drug manufactured and sold by the Defendant caused birth defects. The Plaintiffs were two families that each had a son born with malformed limbs. In both cases, the mothers had taken the drug Bendectin during the first trimester of pregnancy to reduce nausea and vomiting.
The drug had been on the market since 1956 and the FDA deemed it a category A drug, meaning that it did not pose a risk to the fetus if taken during pregnancy. It is a combination of vitamin B6 and doxylamine; the latter is an antihistamine similar to those found in over-the-counter medications used to treat motion sickness. The Defendant drug company removed Bendectin from the market in 1983 after a series of lawsuits from families alleging that the drug had caused birth defects in their children. After the drug was removed from the market, the number of women hospitalized for pregnancy-associated nausea and vomiting increased markedly.
At trial in the Daubert case, the expert witness for the Defendant cited clinical studies involving more than 13,000 patients; these studies demonstrated that Bendectin does not cause birth defects. Meanwhile, the Plaintiffs summoned eight expert witnesses who supported their claims, that the drug does cause birth defects, through a combination of in vitro studies, animal studies, and reanalysis of the data cited in the clinical trials cited by the Defendant. The Supreme Court ruled in favor of the Defendant and, in its decision, outlined a new rule of evidence that came to be known as the Daubert standard.
The Daubert standard specifies that the judge, not the jury, must decide whether to accept the evidence presented by a witness summoned for his or her expertise in a scientific field. The judge must base this decision on whether the research being presented is relevant to the case being tried, whether it is generally accepted in the scientific community, and whether it is based on sound scientific methodology. The Court outlined several “illustrative factors” for evaluating the quality of the scientific methodology underlying the expert witnesses’ claims but cautioned judges against dogmatically using these criteria as a test or checklist. Admissible evidence should be based on studies in which a hypothesis was tested; the study should be replicable, such that it is possible for other researchers to test the same hypothesis. Research that involves theories and techniques commonly applied by professional researchers should be preferred over obscure or controversial theories and techniques. Expert witnesses should cite studies published in peer-review journals. The studies should mention the rate of error, and the smaller the rate of error in the experiment, the better. The study should have been conducted for reasons unrelated to the present legal case.
The purpose of the Daubert standard is to prevent unfounded scientific claims from being used as evidence in civil and criminal cases. It assumes that judges, whose job is to evaluate people’s credibility and who have more time to do background research on the experts’ claims, are in a better position to determine the admissibility of the evidence than juries. Jurors must base their decision solely on what they hear during the trial. Their education levels vary; they may be impressed with the expert’s credentials and may have little prior knowledge about the subject the expert is discussing.
The Daubert standard replaces the Frye “general acceptance” test, which has been in place since 1923. Like the Daubert standard, the Frye test aims to keep pseudoscience out of the courtroom, but it has only one criterion, namely whether the theory or technique being cited is generally accepted in the scientific community. Because “generally accepted” and “scientific community” are fairly subjective terms, many unjust verdicts have resulted from expert testimony admitted because of the Frye standard, including Defendants in criminal cases being convicted on the basis of polygraph tests, bite mark evidence, and analysis of victims’ stomach contents.
Critics of the Daubert standard allege that it is the same as the Frye test, except described in fancier terms. They call for a more specific way of determining when novel scientific theories become generally reliable. With its emphasis on peer review and on replicability, as well as leaving the decision to judges, who are more likely than jurors to have experience evaluating scientific research, the Daubert standard does set the bar higher for scientific research to be used in court.
Bendectin remains off the market, although similar drugs are available to treat pregnancy-related nausea.
