| Why do some leaders take foreign policy risks, while others do not? To answer this question scholars of international relations have largely relied on theories of risk-taking, such as Kahneman and Tversky's (1979) prospect theory, which focus on the role of situational circumstances rather than differences among individuals. This dissertation, however, argues that foreign policy risk-taking can be explained by examining differences in leaders' inherent risk propensities. It develops a personality-led theory of risk-taking based on the results of studies in behavioral economics, organizational psychology, trait psychology, and political psychology, which indicate that differences in individuals' inherent risk propensities are linked to personality traits. Using data on U.S. Presidents' Big Five personality traits, the theory is assessed statistically through two chapters examining presidents' decisions to initiate and escalate international conflicts. These chapters are followed by two case studies of presidential decision making during crises: Harry Truman during the 1948 Berlin Blockade, and John F. Kennedy during the 1961 Berlin ultimatum crisis. While the results of these four empirical chapters are mixed in regards to specific risk-related personality traits, they overall suggest that leaders' inherent risk propensities significantly influence their decisions to initiate conflicts and use force to carry out their policy objectives. This dissertation is the first study to apply the Big Five, the dominant paradigm in trait psychology, to leaders' foreign policy behaviors, and opens the door for future studies in political science to develop and test leader-level theories using objective measures of personality traits. |
