Expert testimony in psychology: Ramifications of Supreme Court decision inKumho Tire Co., Ltd. v. Carmichael

A recent Supreme Court decision, Kumho Tire Co., Ltd. v. Carmichael (March 23, 1999), may have substantial impact on psychological expert testimony. P revious criteria for admissibility of scientific expert testimony now apply broadly to expert testimony, not just testimony narrowly grounded in scien tific evidence. Judges will determine the relevance and reliability of all expert testimony, including that based on clinical experience or training. Admissible testimony will either satisfy the criteria established in Dauber t v. Merrell Dow Pharmaceuticals, Inc. (1993) or meet similarly rigorous st andards judged appropriate to the particular field involved. Because psycho logical testimony has varied in its evidentiary basis, sometimes relying on science and otherwise on clinical training or experience, court decisions will gradually determine the precedent for its admissibility. We also discu ss long-term consequences for the credibility of psychological expert testi mony and the relation between psychology and law.