Prosociality, International Law, and Humanitarian Intervention

A significant insight of behaviouralism and social psychology, well-established through experimental research, is that actors display ‘social preferences’, other-regarding or non-self-interested decision-making. Contrary to rational choice assumptions, people may have only ‘bounded selfishness’ in decisions, caring not only about their own payoffs, but about those of others. This chapter provides a broad framework for assessing the relevance of prosociality to international law, discussing the levels of analysis problem that inheres in any shift from individual psychology to corporate actors such as states. The chapter focuses on one area in which prosociality may enrich discussion of a contested issue in international law and the problems it raises—humanitarian intervention. How can motivation and personality—the main variables of prosociality—apply to international actors? Is the ‘bystander effect’ prevalent in international relations? Which other areas of international law relate to prosociality? And can (or should) international law encourage prosociality?