Is it possible to explain all political behavior in terms of self-interest? If we interpret self-interest as narrow, direct and short-term, the answer is obviously no. Things that we might call culture, ideology, ideas and moral principles clearly affect individual choices, and, thereby, political outcomes. But inquiries into the the logic behind these other forces often bring us back to interest. Much behavior that appears at odds with self-interest can be “rationalized” by considering long time horizons and the complexities of social interaction. In acting against my short-term self-interest, I may be building a useful reputation, winning and maintaining allies, making credible commitments, or establishing a focal point. Recent game theoretic work has shown how patterns of behavior that we might attribute to culture (Kreps 1990, Fearon and Laitin, 1996), partisanship (Aldrich 1995), ideology (Bawn 1999) or ideas (Garret and Weingast 1993, Weingast 1995, Bates, de Figueiredo and Weingast 1998) can arise endogenously in models with no causal force other than self-interest. The seemingly non-interest based behavior arises as the result of long time horizons, uncertainty and complex social interaction.

The success of the rational choice paradigm in explaining seemingly non-interest-based behavior motivates my initial question. What are the limits of self-interest explanations? While this paper cannot offer a comprehensive answer, it explores a particular alternative to interest, moral principle. I will focus here on a case in which the role played by interest seems to be quite small, and the role played by moral principle seems quite large – the abolitionist movement in the United States. The seemingly straightforward claim that the abolitionist movement was motivated by principle begs many questions. Under what circumstances are people motivated by principle? When does principle override interest? Why is a given principle important to one person and not another? Does the “success” of a principle in motivating behavior depend on the logical force of its content, or simply on the social context in which it is invoked?

The argument developed here is that social context matters a lot. Specifically, in some social contexts, some individuals can benefit by taking modestly costly action in defense of a principle that has no direct link to their self-interest. They benefit because by defending the principle, they give a credible signal of their own trustworthiness. The idea that behavior contrary to one’s short-term self interest can act as an effective signal is not new to game theoretic political science. Nor is it novel to claim that abolitionism sprang from a particular vision of social order held by evangelical communities in the early-to-mid 19th century. This paper’s contribution is to show that this vision of social order created an unusual need for individuals to be able signal good intentions to their fellow community members.