How Much Disagreement is Good for Democratic Deliberation?

The ideal of deliberation requires that citizens engage in reasonable discussion despite disagreements. In practice, if their experience is to match this normative ideal, participants in an actual deliberation should prefer moderate disagreement to conflict-free discussion within homogeneous groups, and to conflict-driven discussion where differences are intractable. This article proposes a research design and methods for assessing the quality of a deliberative event based on the perceptions of the participants themselves. In a structured deliberative event, over 2,000 individuals were assigned to small groups composed of about 10 persons of varying levels of ideological difference to discuss health care reform in California. We find that participants experience higher satisfaction with deliberation under moderate ideological difference than when they are in homogeneous or in highly disparate groups. That moderate disagreement induces optimal deliberation is consistent with normative expectations and empirically demonstrates the deliberative quality of this event.