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Denver Sturm College of Law




The Constitution guarantees litigants an 'impartial' jury, one that bases its judgment on the evidence presented in the courtroom, untainted by affiliations with the parties, racial animus, or media coverage that may include inadmissible facts, a one-sided portrayal, and naked opinion. Problems of juror bias arise in almost every trial – state and federal, civil and criminal - and the problem is most severe in the highest profile cases, where the need for accuracy and legitimacy in outcomes is most salient.

The Supreme Court has instructed courts to use a simple method to determine whether jurors are biased: ask them. Studies have shown that the juror’s self-diagnosis is the most important factor for the court’s decision about whether to seat the juror.

To test the reliability of these self-diagnoses, we fielded a randomized controlled experiment, in which we exposed mock jurors to news articles that were either prejudicial to the defendant (in one condition) or irrelevant (in the other condition). We then gave jurors the admonitions and questions endorsed by the Supreme Court for the purpose of identifying biased jurors, prior to all of them watching a 32-minute condensed video of a civil trial, rendering binary judgments, and awarding damages

After we excluded jurors who said that they would be unable to be fair and impartial (or were unsure), the remaining jurors were significantly more likely to rule against the defendant and those that did so also awarded larger damages, than those in the control condition. Thus, juror self-assessments were not related to actual bias. We consider and test alternatives to the self-diagnosis protocol, but ultimately find that broader exclusion of all exposed jurors may be necessary to assure a fair trial.

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