The Effect of Blinded Experts on Jurors’ Verdicts
Forthcoming, Journal of Empirical Legal Studies 9(4) December 2012
32 Pages Posted: 14 Jul 2011 Last revised: 6 Nov 2013
Date Written: September 19, 2012
“Blind expertise” has been proposed as an institutional solution to the problem of bias in expert witness testimony in litigation, as a way to improve litigation outcomes. At the request of a litigant, an intermediary selects a qualified expert and pays the expert to review a case without knowing which side requested the opinion. This paper reports an experiment that tests the hypothesis that, compared to traditional experts, such “blinded experts” will be more persuasive to jurors. A national sample of mock jurors (N = 275) watched an online video of a staged medical malpractice trial, including testimony from two medical experts, one of which (or neither, in the control condition) was randomly assigned to be a blind expert. We also manipulated whether the judge provided a special jury instruction explaining the blinding concept.
Descriptively, the data suggest juror reluctance to impose liability. Despite an experimental design that included negligent medical care, only 46 percent of the jurors found negligence in the control condition, which represents the status quo.
Blind experts, testifying on either side, were perceived as significantly more credible, and were more highly persuasive, in that they doubled (or halved) the odds of a favorable verdict, and increased (or decreased) simulated damages awards by over $100,000. The increased damages award appears to be due to jurors hedging their damages awards, which interacted with the blind expert as a driver of certainty. Use of a blind expert may be a rational strategy for litigants, even without judicial intervention in the form of special jury instructions or otherwise.
Keywords: Bias, Expert testimony, Juror decision making, Credibility, Scientific reasoning
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