The Diffusion of Protestantism in Northern Europe: Historical Embeddedness and Complex Contagions in the Adoption of the Reformation

Abstract

In this article we use network theory to explain the adoption of the Protestant Reformation. We use new historical data on the connections between Hansa towns that allow us to conduct the first social network study of the Protestant Reformation. Based on an analysis of cities in central and Western Europe between 1517 and 1530, we find evidence for diffusion through both simple and complex contagion. Our operationalization of network data based on medieval Hansa Diets points to the complex association between tie weights (i.e., the strength of ties) and numbers of ties in network diffusion. Using optimal tuning parameters for simple adoption models, we show that a combination of strong ties and weak ties fostered Protestant adoption in northern cities.

Multiplex Network Ties and the Spatial Diffusion of Radical Innovations: Martin Luther’s Leadership in the Early Reformation

“…Anti-Protestant "controversialists" were active early on in this region and urged cities to hold fast to the Roman Church (Bagchi 1991). These cities also had many trading ties with anti-Protestant countries (Wurpts et al 2018). Finally, imperial influence was strong because the region was governed by Habsburg regents and their allies who empowered local magistrates to censor Lutheran texts and arrest (and in some instances, execute) Protestant preachers and agitators as heretics.…”

“…Previous studies have not measured Luther's influence using network analysis. Other studies delineate various pathways, such as spatial neighbors (Cantoni 2012) or involvement in the Hanseatic trading league (Wurpts et al 2018), by which the Reformation could have spread, but our concern is to examine how a framework of multiplex networks with multiple diffusion can explain the impact of the leader on the spread of an insurgent movement.…”

“…Luther's gripping pamphlets and translation of the New Testament were carried in traders' wagons and in the holds of ships, connecting cities with presses to those without (Edwards 1994). Merchants persuaded by Luther's message shared their opinion with colleagues and business associates (Wurpts et al 2018).…”

“…If diffusion does not require connections with influential leaders at all, but rather occurs virally through contact with similar others (Watts and Dodds 2007:442), spatial diffusion is another candidate for explaining the spread of Protestantism. In early modern Europe, the flow of people, goods, and information occurred chiefly through channels of trade, making merchants diffusion vectors (Wurpts, Corcoran, and Pfaff 2018). We would expect cities that adopted Protestantism to influence adjacent others via trade routes and thereby contribute to the spatial diffusion of the Reformation.…”

The Diffusion of Exclusion: Medieval Expulsions of Jews

“…Prior studies of medieval European expulsions have investigated expulsion as a domestic process, but of course policy decisions are a product of both domestic and external factors (Myers 2000;Shipan and Volden 2008). By external factors, I mean the social structures and relationships that influence rulers' choices (Burt 1987;Hedstrom, Sandell, and Stern 2000;Strang 1991;Wurpts, Corcoran, and Pfaff 2018). There are two ways to think about social influence.…”