Marriage provides little additional life satisfaction boost beyond that of partnership and cohabitation

A new large-scale study finds that people’s overall satisfaction with life increases significantly when they transition from living alone to cohabiting with a romantic partner. The research indicates that the most substantial improvement in well-being is linked to the formation of the relationship itself, with gains often appearing before the couple starts living under the same roof. The research was published in the Journal of Personality.

Being in a romantic relationship is often associated with benefits like better health, increased social support, and greater life satisfaction. As life satisfaction is a strong predictor of general mental health, understanding the events that influence it is an important area of study. In many Western cultures, the traditional sequence of life events from being single to getting married has changed, with cohabitation before marriage becoming increasingly common.

This shift raises questions about which specific milestones in a relationship contribute most to a person’s sense of happiness. Previous research has often shown that married individuals report higher life satisfaction than single people, but it has been less clear whether this boost comes from marriage itself, the act of moving in together, or simply from starting a new relationship. The researchers of this study wanted to disentangle these connected events to better understand their individual associations with life satisfaction.

The investigation aimed to address several specific questions. First, the researchers sought to map the trajectory of life satisfaction as individuals moved from being single and living alone to entering a relationship and then cohabiting. They wanted to see how large the increase in well-being was and if it was sustained over the first few years of living together. Second, they wanted to examine if getting married around the same time as moving in provided an additional, separate boost to life satisfaction.

They were also curious if the link between marriage and well-being has changed over the past few decades, as social norms around cohabitation have evolved. Finally, the study explored whether changes in life satisfaction around this transition varied based on personal characteristics like a person’s age, gender, income, education level, or country of residence.

To conduct their analysis, the research team utilized data from two major, long-term national surveys: the German Socio-Economic Panel, with data collected between 1984 and 2019, and the UK Household Longitudinal Study, with data from 2009 to 2019. These surveys track thousands of households and individuals over many years, asking them annually about various aspects of their lives, including their relationship status, living arrangements, and overall life satisfaction.

The researchers implemented a very specific selection process to create a clean comparison group. They identified all participants who, at some point, reported being single and living alone. From this group, they focused only on those who subsequently entered a new romantic relationship and moved in with that partner. To avoid complicating factors, they excluded individuals who had children in the household or who got married before they began living with their partner. This meticulous filtering resulted in a final sample of 1,103 people who followed this specific life path.

For each person in the final sample, the researchers analyzed their reported life satisfaction over a five-year window centered on the year they moved in with their partner. This timeline included the two years before cohabitation, the year of the event itself, and the two years that followed. This method allowed the team to establish a baseline of life satisfaction while single and then track how it changed during and after this major life transition.

The findings showed a distinct pattern. Life satisfaction reached its highest point in the year that participants first moved in with their new partner. Compared to two years prior, when they were single and living alone, their satisfaction had risen by a noticeable amount. The analysis revealed that this peak was followed by a slight decline in the next two years. However, even with this small drop, their life satisfaction remained significantly higher than it had been during their time as a single person living alone.

To better understand what was driving this increase, the researchers performed a more detailed analysis on a subgroup of participants. They looked specifically at individuals who were already in a relationship one year before they moved in together. For this group, a large part of the increase in life satisfaction had already occurred by that one-year-before mark. Their well-being was already elevated while they were in a relationship but still living alone.

When they eventually moved in with their partner, their high level of life satisfaction was maintained but did not experience another significant jump. This result suggests that the formation of the romantic partnership itself, rather than the physical act of cohabiting, is the primary event associated with the initial boost in well-being.

When the researchers examined the role of marriage, they found it had a limited additional effect. There was no consistent evidence that getting married at the same time or shortly after moving in together provided an extra surge in life satisfaction on top of the gains from cohabitation.

One interesting historical pattern did emerge from the German data. For participants who moved in together around the year 1993, getting married was associated with a temporary extra boost in happiness one year later. But for participants in more recent years, and for all participants in the United Kingdom data, this effect was absent. This suggests that as unmarried cohabitation has become more socially accepted, the unique contribution of marriage to well-being may have diminished over time.

The study also found that the pattern of rising life satisfaction was largely consistent across different demographic groups. There were no significant differences between men and women in their life satisfaction trajectories around this transition. However, age and income did show some minor influence. Older participants reported lower life satisfaction two years before moving in compared to younger participants. Individuals with higher incomes reported greater life satisfaction one year before moving in, and their well-being did not decline as much in the years that followed compared to those with lower incomes.

The authors acknowledge certain limitations of their work. The findings are based on correlational data, which means it is not possible to definitively state that moving in with a partner causes an increase in life satisfaction; other unmeasured factors could be involved. The study also relied on a single question to measure life satisfaction. The highly specific sample of people who followed a particular relationship path, while strengthening the internal comparisons, may limit how broadly the findings can be applied to the general population. Finally, because the data came from Germany and the United Kingdom, the results may not be applicable to other cultures with different social norms regarding relationships and cohabitation.

For future research, the team suggests further investigation into the mechanisms behind their findings. It would be beneficial to explore why individuals with lower incomes experience a steeper decline in life satisfaction after the initial cohabitation peak. Additional studies in different countries could help determine if these patterns are universal or culturally specific. Researchers could also examine how personality traits, such as extraversion, might interact with relationship transitions to influence a person’s well-being over time.

The study, “Mapping Life Satisfaction Over the First Years of Cohabitation Among Former Singles Living Alone in UK and Germany,” was authored by Usama EL-Awad, Robert Eves, Justin Hachenberger, Theresa M. Entringer, Robin Goodwin, Anu Realo, and Sakari Lemola.