ABSTRACT
Introduction Central to the notion of the microfoundations of behavioral IR is that individuals matter in the conduct of foreign policy making. Further, if individuals matter, it must also be the case that they differ from one another; if individuals behaved the same, then which individual occupied the leadership position would not matter. One thing that makes individuals different from each other is their psychology, i.e., their mental and behavioral characteristics. While it is obvious that individuals are different from each other; what is less clear is whether or not those differences matter in foreign policy making. This empirical question lies at the heart of this chapter: Do the psychological characteristics of U.S. leaders affect the conduct of foreign policy in their respective administrations?
