Cohabitation Changes People: Contemporary European Evidence

Martin Kreidl and Zuzana Zilincíková’s 2021 contribution to European Sociological Review has resurrected a strand of cohabitation research that had been dormant since the 1990s. They show that across nine European countries, cohabitants (those living in unmarried romantic relationships) became more approving of divorce while living together. 

Why is this new work so remarkable? Because much cohabitation research in the past quarter century has focused on the characteristics of those who choose to cohabit versus marry—not on how people’s characteristics (i.e., their attitudes towards family dissolution) change during cohabitation. Such changes in attitudes have measurable consequences: favorable attitudes toward divorce are linked to patterns of marital interaction that decrease marital quality and increase the likelihood of divorce.

The most optimal research design for finding out whether cohabitation fosters attitudes supporting divorce is to measure attitudes before entering unions and then again after experiencing those unions (i.e., to look at change within the same individuals as their experiences unfold). Researchers have done this before: attitudinal data were gathered from individuals living in the Detroit, Michigan metro area, first at age 18 in 1980, and again at age 23 in 1985. Of the 789 young adults interviewed at both time points, 176 had married without first cohabiting and 207 had cohabited between the two surveys.¹ Using this data, a 1992 study found that people who cohabited became more accepting of divorce, while people who married became less accepting. A 1997 study added that permissiveness toward divorce grew with the length of the cohabitation.

There you have it: before Kreidl and Zilincíková, the best research establishing that cohabitation itself contributed to a greater acceptance of divorce was based on what happened to 383 people between the ages of 18 and 23 in three Michigan counties.²

There has not been counterevidence amassed against this claim; there are no studies showing that cohabiting has no effect on attitudes about marriage and divorce.³ But family researchers referring to work on how cohabitation liberalizes divorce attitudes have had to cite studies that—while done by respected researchers and published in top journals—had not been replicated, not for a broader age range, nor more recent time periods, nor larger geographic areas. It was frustrating, to say the least. 

So we were thankful for Kreidl and Zilincíková's new study, "How Does Cohabitation Change People’s Attitudes toward Family Dissolution?" before we even knew the answer to the question they posed. We were relieved that there would finally be some contemporary evidence. Arguably, even if the findings from the 1980s were generalizable beyond metro Detroit, cohabitation might have diminished effects as it has become more commonplace. Contributing knowledge about cohabitation from across Europe is also important because union dynamics are quite distinct in the United States.

Kreidl and Zilincíková used 18–45-year-old individuals who had never been in a union (cohabiting or married) in the first wave of the Generations and Gender survey (circa 2004), and who were successfully interviewed in the second wave (three-to-four years later). This gave them the divorce attitudes of 6,164 individuals living in nine European countries before they ever entered unions. The vast majority were still never partnered at wave two: 308 married, and 684 entered into their first cohabitating union. Compared to the 1980’s research in metro Detroit, this sample was larger and more diverse in age-range and location. The analytic strategy was the same: by focusing on how the same people's attuditudes changed over time (i.e., within-person change), the researchers were able to control for the fact that people who entered cohabitation were more liberal to start with, and instead measure how the experience of cohabitation changed attitudes.

Across their nine European countries in the mid 2000s, Kreidl and Zilincíková find that people who cohabited tended to move towards a more permissive view of divorce, and people who married tended to move toward a less permissive view of divorce—just like individuals in the Detroit area in the 1980s. One nuance they uncovered was that entering a union of any kind made people less tolerant of divorce. Then, over time, cohabitants, on average, returned to their initial attitudes and eventually became more permissive the longer they remained in their cohabiting union. In contrast, marrieds, on average, continued to become less accepting of divorce.

The researchers had expected that cohabitation would have stronger effects in the countries of Central and Eastern Europe where cohabitation is less marriage-like than in Western Europe, but instead, they found that their results were similar everywhere. However, the cohabitation effect on divorce attitudes was statistically indistinguishable from zero in some countries. Both of these findings might be attributed to the 684 cohabitants being unevenly distributed across the nine countries. It is easier to find statistical distinctiveness in bigger samples.

The authors stopped short of fully endorsing a causal interpretation of their data. Even though following the same individuals over time could show how experience changes people, they also note that their finding that longer cohabitations produce more change in people’s attitudes might also be explained by people with less malleable attitudes either breaking up or marrying.

Nonetheless, Kreidl and Zilincíková conclude that the current multiplicity of family trajectories is the product of more liberal attitudes regarding family life and that experiencing cohabitation 

also serves as a catalyst for a value change and further contributes, at the individual level, to a shift toward a less traditional normative standpoint. Thus, the strength of liberal values and unmarried cohabitations reinforce each other. 

We are not sure why it took decades for researchers to reinvestigate the role of cohabitation in promoting liberal values, but we suspect the topic is uncomfortable. Cohabitation has emerged partly because of the rise of individualism, and individualism in its extreme treats values as personal characteristics. The conclusion that relationships change people—and, in particular, that cohabitation, which is associated with less interdependence than marriage, also changes people’s attitudes—may be disquieting. That conclusion had a sound empirical base in the 1980s, and it has an even stronger foundation today. Cohabitation is both a consequence of and a catalyst for liberal values. 

Laurie DeRose is a senior fellow at the Institute for Family Studies, Assistant Professor of Sociology at the Catholic University of America, and Director of Research for the World Family Map Project. Rebecca Oldroyd is a final year PhD student at Queen Mary University of London whose research focuses on the effects of family instability on child development.

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1. Some of the cohabiting unions had been converted to marriages, some had dissolved, and others were still cohabiting in 1985.

2. This was not the only evidence showing that cohabitation can contribute to divorce risk; it was just the only evidence using attitudes toward divorce. Other mechanisms through which cohabitation can increase the risk of divorce include how cohabitation fosters constraint commitments and how cohabitation is linked to more marital conflict, less marital happiness, and less marital communication (this finding is net of the selection effect which the researchers controlled using longitudinal data as in the Detroit studies described above).

3. A follow-up of the Detroit area panel at age 31 found that marriage decreased divorce tolerance, but those who married a cohabiting partner were "inoculated" against the traditionalizing effect of marriage. In other words, the subset of cohabitors that later married did not experience increasing divorce tolerance, but neither did they experience the decreasing divorce tolerance otherwise associated with marital duration.