Nullification Instructions and Anger Increase Jurors’ Reliance on Attitudes in Verdict Decisions

American law gives jurors the right to return a not-guilty verdict when their conscience demands it but the law directs otherwise – a phenomenon known as jury nullification. Yet courts have historically avoided informing jurors explicitly about their nullification power, for fear that such knowledge would prompt jurors to disregard the law and rely on their personal biases, attitudes, and emotions. Prior research suggests that attitudes can influence verdicts, as can emotions such as anger, which may deplete jurors’ ability to process information carefully and increase their reliance on heuristics. I explored the effect of jury nullification instructions on the relation between jurors’ attitudes toward a crime (euthanasia), their emotions (anger), and verdicts. As predicted, pro-euthanasia jurors were less likely to give a guilty verdict than anti-euthanasia jurors, an effect mediated by feelings toward the defendant and anticipated affect (but not by perceptions of the defendant). Nullification (versus standard) instructions resulted in reduced guilt ratings. A significant three-way interaction qualified these results. Euthanasia attitudes had no effect on verdicts when jurors were in an emotionally neutral (compared to induced anger) condition and received standard instructions. In contrast, attitudes had the expected effect on verdicts when jurors were in the induced anger condition and received standard instructions, and when jurors were in the emotionally neutral condition and received nullification instructions. The only unexpected finding was that attitudes did not affect verdicts when jurors were both in the anger and nullification instruction condition. Implications are discussed.