The Effect of Blinded Experts on Juror Verdicts

Abstract

“Blind expertise” has been proposed as an institutional solution to the problem of bias in expert witness testimony in litigation (Robertson ). 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 article 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 whom (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.

Why do forensic experts disagree? Sources of unreliability and bias in forensic psychology evaluations.

“…For example, evaluators could try using a case manager, an individual who communicates with attorneys and controls the inflow and outflow of information, in order to prevent irrelevant biasing information (such as the identity of the retaining party) from reaching the evaluator (Dror, 2013). Evaluators may soon be able to market (to attorneys or the court) their willingness to serve as blinded experts, since research suggests that mock jurors view the testimony of blinded experts as more credible (Robertson & Yokum, 2012).…”

Field reliability of competency and sanity opinions: A systematic review and meta-analysis.

“…be known so that judges have enough information to perform their gatekeeping role in excluding unreliable testimony. Knowing the error rates associated with admitted scientific testimony would also presumably help the trier of fact weigh the value of such testimony appropriately (Robertson & Yokum, 2012).…”

How confession characteristics impact juror perceptions of evidence in criminal trials

“…Similarly, Levett and Bull Kovera (2008) found that jurors thought experts for both sides were less credible when opposition to an expert's testimony was offered by another expert. One possible solution would be to follow Robertson and Yokum's (2012) suggestion that courts use so-called "blinded experts" to review a case without being told which side they would work for. Robertson and Yokum (2012) found that blinded experts were rated as more credible and more influential.…”

“…One possible solution would be to follow Robertson and Yokum's (2012) suggestion that courts use so-called "blinded experts" to review a case without being told which side they would work for. Robertson and Yokum (2012) found that blinded experts were rated as more credible and more influential.…”