Most of the Immigrants in Germany come from societies with traditional family patterns like South Eastern Europe and Turkey. Families from those would be considered as stable having a low divorce rate. But when people are disembodied from their original country and marry a German partner, this changes, as a on mixed marriages in Germany showed.
Risk of divorce in binational marriages is significantly higher than in marriages of partners with the same origin, significantly means about 60% higher. Though the researchers could only rely on questionnaires measuring specific indicators, not going into depth of value construction, family relations or cultural dispositions, they found some indication for the causes of the difference.
Religious affiliation matters. Though we have no data about religious practice, the indicator shows the historical effectiveness of religion. Even only affiliation to a religion marked in the questionnaire, without deeper commitment, correlates with lower risk of divorce; and the cultural difference is higher with migrants from Turkey than from other Southern or South East European States. The risk of getting divorced declines when children are present.
Cohabitation, living together before marriage, lowers the risk of divorce, but this does rarely happen with partners with a background of migration from Turkey or South of Europe. Cohabitation is not a generally accepted pattern in those countries.
Risk of separation also rises if the age of the bride was in her early twenties – than the risk is three quarters higher compared to older marriage age. If she has no or only a low educational degree than again risk of divorce increases.
The authors concentrated on women, but when including indicators for the husband like age difference or religious affiliation, the risk decreases from 60% down to a third over all the couples. If he is younger though (two years or more) than the bride and has a lower educational performance than she has or different religious affiliation the risk of divorce raises.
Those are data, what do they imply?
It might be dangerous just to conclude: it is the nation that matters. You are better advised to look more closely at the indicators. We find that religion, cohabitation, age and education matters – and that would be true with partners from the same nation too. If partners value different lifestyles, belong to distant generations or differ widely in the educational degree risk of divorce raises even when they come from the same nation. That those indicators are differently distributed between nations is another story. With emphasizing on nations we legitimize differences between nations that are differences in very specific issues within and across nations.