Chaos in the courtroom reconsidered: emotional bias and juror nullification.

A widespread presumption in the law is that giving jurors nullification instructions would result in "chaos"-jurors guided not by law but by their emotions and personal biases. We propose a model of juror nullification that posits an interaction between the nature of the trial (viz. whether the fairness of the law is at issue), nullification instructions, and emotional biases on juror decision-making. Mock jurors considered a trial online which varied the presence a nullification instructions, whether the trial raised issues of the law's fairness (murder for profit vs. euthanasia), and emotionally biasing information (that affected jurors' liking for the victim). Only when jurors were in receipt of nullification instructions in a nullification-relevant trial were they sensitive to emotionally biasing information. Emotional biases did not affect evidence processing but did affect emotional reactions and verdicts, providing the strongest support to date for the chaos theory.