A comparative law analysis of the standard for admitting scientific evidence: The united states stands alone

Abstract

In the United States, most courts of law require that a party offering scientific testimony show that the underlying scientific theory has gained general acceptance within the pertinent scientific community. In deciding whether a scientific technique is reliable enough to be admitted, other legal systems consider the extent of the acceptance of the technique as a relevant factor. However, no other legal system — socialist, civil law, or common law — has elevated general acceptance to the status of a hard-and-fast requirement for the admission of scientific evidence. From a comparative law perspective, the general acceptance test followed by most American courts is suspect; the test does not seem to be justified by any unique feature of the American legal system. The proponents of the test sometimes argue that the test helps counteract the bias which expert witnesses tend to develop in the American adversary system. However, the same problem of bias arises in all common law countries in which the attorneys hire, call, and question the experts. The proponents also contend that the test ensures that there will be a reserve of experts to critique the scientific testimony. However, this contention rests on a misunderstanding of the scientific process; if given adequate discovery, the opposing attorney can request that another expert duplicate the experiment to test the validity of a novel theory. Finally, the proponents argue that the test is necessary in the United States because the United States makes the most extensive use of lay jurors. This argument rests on the assumption that lay jurors are incapable of critically evaluating scientific testimony. The available empirical studies belie that assumption. Moreover, although many other legal systems allow laity to participate in the judicial process, no other legal system has gone to the length of altogether barring lay decision-makers from considering novel scientific techniques.