Neuro-Voir Dire and the Architecture of Bias

Courts and commentators routinely assume that “bias” on the jury encompasses any source of influence upon jurors that does not come directly from the evidence presented at trial. This sweeping conception of juror bias is flawed because it fails to distinguish the prejudices and affinities that infect jury decisionmaking from the experiences and perspectives that enrich it. This Article uses a thought experiment informed by the neuroscience of bias to illuminate the complexity of juror influences that go by the name of bias. I distinguish four distinct categories of juror influence: personal interests, community interests, case-specific beliefs, and case-general beliefs. I apply this spectrum of juror bias to provide a sounder way to think about what kind of juries we want. I argue that trial courts should limit the interrogation and disqualification of prospective jurors to personal interests in the case—whether social or financial—and to case-specific beliefs arising from pretrial facts or rumors about the parties or events. By contrast, I would permit no such wholesale exclusion, either for community interests, which range from principles of justice to desires for vengeance, or for case-general beliefs about social causes or groups, which span scruples to dogmatism, and empathy to bigotry. My proposal to abolish challenges for these latter categories of outside influence raises the serious concern that accommodating their presence on the jury risks facilitating unjust outcomes, jury nullification, and hung juries. Trial courts should mitigate these risks by adopting two bias-tempering measures. First, jury pools should be diversified in ways that social cognition research suggests would attenuate the influence of unreflexive or objectionable attitudes. Second, judges should instruct deliberating jurors to express, along with their own position, the strongest counterarguments to it, so as to disrupt exaggerated assumptions of division and facilitate openness to persuasion