Discordance between language use and ethnolinguistic affiliation predicts divorce of exogamous couples

A large literature has found that when two spouses have different ethnic, racial, religious or linguistic identities, they are more likely to divorce than endogamous counterparts. This paper is the first to use longitudinal population registers to illustrate that, giving in on the everyday language use may amplify the divorce risk of intermarried couples. It draws on theories of ethnic boundary shifting and boundary crossing to examine two main ancestral groups in Finland, Finnish speakers and Swedish speakers, between whom intermarriage is common. Administrative changes in how ethnicity was registered between the censuses of 1975 and 1980 make it possible to identify individuals who are discordant on ethnolinguistic affiliation and the language mainly used. Cox regressions are employed to study the subsequent divorce risk, using data on the married Finnish population, and adjusting for a number of individual-level control variables. Results suggest that couples who are endogamous on the main language used, but exogamous on ethnolinguistic affiliation, run a higher divorce risk than couples who are exogamous in both respects. Furthermore, the divorce risk is greater for couples where one partner has shifted towards the majority group of Finnish speakers, compared to couples where one spouse has shifted towards the minority group of Swedish speakers. Adopting the spouse’s language, meaning that there is language convergence in the couple, consequently influences marital stability.