Jury Nullification Instructions as Amplifiers of Bias

Norbert L. Kerr, Michigan State University
Franklin J. Boster, Michigan State University
Craig R. Callen, Michigan State University College of Law
Mary E. Braz, Michigan State University
Barbara O'Brien, Michigan State University College of Law
Irwin Horowitz, Oregon State University

Abstract

Recently, Horowitz and his colleagues (2006) showed that evidence that was emotionally biasing for jurors (specifically, irrelevant information about the character of a crime victim) exerted a stronger effect on juror judgment if those jurors had received instructions that explicitly endorsed jurors' ability to nullify rather than standard instructions—what one might call the ``amplification effect" of the nullification instructions. This paper reports a jury simulation study that employed a nullification instruction in addition to those Horowitz, et al., used—one that explicitly cautioned mock jurors not to confuse the emotions aroused by the potential unfairness applying the law with similar emotions aroused by biasing information (the ``null plus" instructions). The null-plus instruction did not negate the amplification effect of the nullification instructions. Unexpectedly, mock jurors who received nullification or null plus instructions were more likely to convict the killer of an unsympathetic victim than of a sympathetic one, but those who received standard instructions were not sensitive to biasing victim information. While Horowitz, et al. (2006) also found evidence that jurors who received nullification instructions were affected by emotionally biasing information more than those who did not, the direction of the relationship between victim information and verdicts was reversed (that is, an unsympathetic victim resulted in more acquittals). The contrast between the two studies' findings suggests that nullification instructions may trigger certain biases, but that further research will be needed to specify the direction of such biases.

Recommended Citation

Kerr, Norbert L.; Boster, Franklin J.; Callen, Craig R.; Braz, Mary E.; O'Brien, Barbara; and Horowitz, Irwin (2008) "Jury Nullification Instructions as Amplifiers of Bias," International Commentary on Evidence: Vol. 6 : Iss. 1, Article 2.
Available at: http://www.bepress.com/ice/vol6/iss1/art2

 
 
 
 

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