Birds of a Feather: Patterns of Judicial Decision-Making at the International Court of Justice, 1946-2015

The technical legal expertise of the International Court of Justice (ICJ), the principal judicial organ of the United Nations, is rarely questioned. However, from its inception critics have questioned its partiality by drawing attention to apparent extrajudicial influences on its decisions. While there has been no lack of research assessing the ICJ judges’ voting behavior, methodological limitations of prior research designs have stymied empirical assessments of the extent and nature of extrajudicial factors’ influence over the ICJ judges’ voting behaviors. This dissertation challenges previous research concluding that political and military alignments have no effect on judicial decision-making. In contrast to previous research findings, this dissertation reports that ICJ judges vote closely with those from countries that have regional or military alignments with the countries that nominate or appoint them. Judges from countries with a similar degree of economic and democratic development, and with cultural or religious similarities, also voted closely with each other. This dissertation concludes with a consideration of the causes and implications of the influence of non-legal factors on the World Court’s decisions