Socioeconomic advantage or community attachment? A register-based study on the secularization difference between Finnish and Swedish speakers in Finland

Theories suggesting a unilineal development toward secularization have been challenged by research showing diverse patterns of religious changes across contexts. In Europe, the relevant research has been limited, lacking representative data for minority groups, especially in highly secular and historically religiously homogeneous Nordic settings. We offer a pioneering study using national register data to study the religious changes in Finland over the past five decades. Finland has two native ethnolinguistic groups—Finnish and Swedish speakers—which share the same religious tradition and offer a unique study context. We use register data with longitudinal information on every individual’s religious affiliation to investigate whether the two groups differ in this respect, exploring the possible mechanisms behind this. We find that the Swedish-speaking population is consistently more affiliated with the National Lutheran Church than the Finnish-speaking population. The Swedish-speaking group in Finland has a higher National Lutheran Church affiliation rate, despite being in some aspects socioeconomically advantaged in Finnish society, which is contrary to the expectation of modernization theory. The higher affiliation rate of Swedish speakers can be partly explained by lower levels of internal migration, possibly driven by stronger community attachment. We also find less socioeconomic differences in religious affiliation among Swedish speakers.