This essay reviews the intersection between institutional and psychological conditions that occurs in multiparty coalition cabinets and the effects on foreign policy and decision making. Parallel research in social psychology and foreign policy can provide clues to the underlying mechanisms linking institutional context to policymaking and policy choices. The psychological processes involved in group polarization, persuasion, and other influence strategies as well as psychological factors affecting the quality of decision making are important in coalition cabinets and are reinforced by the particular institutional dynamics of multiparty governance. Indeed, this essay proposes that future research focus on contingency factors in the policymaking process, given the competing views on the effects of multiple advocacy on the quality of decision making and on the types of foreign policies associated with multiparty cabinets. More broadly, this essay supports the view that a highly structural understanding of the effects of institutions on politics and policies is incomplete and that research on the interplay among structures and human agents is critical.