Rationality and Psychology in International Politics

The ubiquitous yet inaccurate belief in international relations scholarship that cognitive biases and emotion cause only mistakes distorts the field's understanding of the relationship between rationality and psychology in three ways. If psychology explains only mistakes (or deviations from rationality), then (1) rationality must be free of psychology; (2) psychological explanations require rational baselines; and (3) psychology cannot explain accurate judgments. This view of the relationship between rationality and psychology is coherent and logical, but wrong. Although undermining one of these three beliefs is sufficient to undermine the others, I address each belief—or myth—in turn. The point is not that psychological models should replace rational models, but that no single approach has a lock on understanding rationality. In some important contexts (such as in strategic choice) or when using certain concepts (such as trust, identity, justice, or reputation), an explicitly psychological approach to rationality may beat a rationalist one.I thank Deborah Avant, James Caporaso, James Davis, Bryan Jones, Margaret Levi, Peter Liberman, Lisa Martin, Susan Peterson, Jason Scheideman, Jack Snyder, Michael Taylor, two anonymous reviewers, and especially Robert Jervis and Elizabeth Kier for their thoughtful comments and critiques. Jason Scheideman also helped with research assistance.