| This study enters the debate over the impact of personality on foreign policy decision-making by examining the link between the personalities of key decisionmakers, in this case U.S. senators, and isolationism or internationalism in roll-call voting on foreign policy issues. To ground these personality effects within an international political context, I examine measures of systemic interdependence and control for the potential effects of domestic constituency and institutional variables. Previous researchers treat the integrative complexity of decisionmaker's statements as indicative of authoritarianism, a broader concept that includes cognitive rigidity, inflexibility, dichotomous thinking, and strong polarized opinions of others. I score the integrative complexity of floor speeches of U.S. senators in four different foreign policy issues (peace/security, foreign trade/economy, environmental protection, and foreign aid). I assess how integrative complexity, an indication of personality, and the extent of interdependence affect roll-call votes in the U.S. Senate at nine time points during the twentieth century: 1911–12, 1921–22, 1931–32, 1939–40, 1951–52, 1961–62, 1971–72, 1981–82, and 1991–92. Generally speaking, integrative complexity and international interdependence significantly influence foreign policy roll-call votes in the U.S. Senate. However, the effects of these influences change over time and in each issue area. Thus, complex thinking in an increasingly complex and interdependent world influences an important aspect of elite foreign policy decision-making behavior. |
