resolved by cross-examination. Courts are not designed to determine whether scientific conclusions are correct.

Participants discussed further comparisons between peer review and cross-examination. Research performed for the purpose of litigation may afford no opportunity for true peer review, especially if the results were obtained recently. One lawyer noted that cross-examination can perform this function and can itself be an incentive to perform good, transparent science, and can even drive science forward. He provided the example that DNA identification litigation had driven DNA technology standards for laboratories.


In trying to determine whether there is a causative connection between Product A and Health Effect B, the Daubert trilogy directed the courts to look to the underlying foundation of the scientific testimony. Consequently, said an academic legal expert, the courts sometime seem to assume that the scientific community and the courts are examining the same concept of causation. When courts see that evidence is inconclusive from a scientific perspective they may decide that it thereby fails the Trilogy standards and should be excluded. This is a simplistic formula-tion, said the scholar, because it neglects to take into account some of the qualities of science and how they differ from those of the law.

Further, the speaker noted, it would be a mistake to assume that science and law are answering the same questions when asked to determine causation. The scientific process operates by testing hypotheses and rejecting those that are inconsistent with the data. The court system may exclude valuable knowledge from the deliberations when it excludes the results obtained in testing inconclusive hypotheses. The courts need to ask themselves, she said, whether such stringent scientific standards make sense in the legal setting.

The legal process approaches causation in a different way. A not-proven verdict in the courtroom has a clear significance. If one party fails to make a convincing case to the jury, it does not mean that more research should be done or that an assertion should be improved. It means that the party loses the case.


On many issues of causation in tort law, pointed out a lawyer, there is scientific uncertainty. Yet in order to win the plaintiff does not have to prove beyond a reasonable doubt that the defendant caused the injury; the cause must only be “likelier than not.”

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