Instructing on death: Psychologists, juries, and judges

The American legal system depends on judicial instructions to structure jury death penalty decisions and thus avoid unconstitutional arbitrariness. Some death penalty instructions, however, provide woefully inadequate guidance and ignore schemas that lead jurors to misconstrue instructions. Empirical research has just begun to document sources of misunderstanding and ways to improve communication. Psychological research can assist in reducing arbitrariness in death penalty decisions, but even optimal instructions may not produce constitutionally sufficient consistency. To be constitutional, capital punishment must be imposed according to a consistent set of standards. Simultaneously, juries must be free to consider in mitigation any relevant case or offender characteristic. It is far from clear that this constitutional conflict between standards and discretion can be resolved.