The common denominator of nettlesome war powers questions is who should make the difficult and freighted decisions about whether the nation goes to war, how it fights a war, and when it ends a war. Surprisingly, however, scholars and commentators rarely (if ever) discuss how psychological research on decisionmaking impacts the constitutional design and doctrine around war powers issues. In the last four decades, psychologists have demonstrated systematic biases in individual and group decisionmaking processes. This behavioral revolution has been no stranger to legal scholarship, particularly in the field of law and economics, where it has been used as a corrective to some of the oversights of the more rationalist approaches that preceded it. The behavioral revolution has also provided important insights to scholars of international relations, where political scientists increasingly write in the subfield of political psychology and international relations. In fact, psychologist Daniel Kahneman and political scientist Jonathan Renshon have recently collaborated on an important article that argues that behavioral psychology has valuable lessons for decisionmaking on war and peace. Over at the NYU Law Review, we have a new Article that introduces important lessons from behavioral psychology into constitutional debates on the doctrine, structure, and design of war powers. We explore how a variety of behavioral lessons (we don’t cover everything, but hit the big ones) can be applied to contemporary doctrinal debates in war powers—debates about threatening wars, initiating wars, fighting wars, and ending wars. These debates include some of the most important from the last fifteen years, including the ability of the President to use force without prior congressional approval, as well as the scope of the Commander-in-Chief power in allowing the President to override congressional restrictions on war-fighting tactics. We also identify broad insights and particular design strategies that, independent of contemporary debates or doctrinal constraints, are worth considering when assessing the design of war powers (though they might be particularly of interest to those engaged in debates over the design of a new AUMF or a revised War Powers Resolution). Our hope is that introducing these psychological considerations into the conversation will help us to better understand persistent problems affecting decisions on war and peace, and to identify ways of addressing them. Ganesh Sitaraman is an Assistant Professor of Law at Vanderbilt Law School David Zionts is a lawyer in Washington, D.C.