A number of studies show that cohabiting couples are more likely to experience physical aggression in their relationships than married couples.[i] Two studies shed light on this subject by exploring how aggression in the relationships of individuals (mostly) in their 20s is associated with various commitment dynamics. Wendy Manning, Monica Longmore, and Peggy Giordano’s new study, Cohabitation and intimate partner violence during emerging adulthood: High constraints and low commitment,[ii] shares some themes with an earlier study of ours (Rhoades et al., in 2010): Physical aggression in unmarried relationships: The roles of commitment and constraints.[iii]
Scott M. Stanley Ph.D. is a research professor and codirector of the Center for Marital and Family Studies at the University of Denver. He has published widely in terms of journal articles and book chapters, with research interests including relationship commitment, cohabitation, conflict, confidence, risk factors for divorce, and the prevention of marital distress. Along with Dr. Howard Markman and colleagues, he has been involved in the research, development, and refinement of the Prevention and Relationship Enhancement Program (PREP) for over 30 years.
Editor: Saad Shaheed
In both studies, physical aggression was measured as having some history of behaviors such as pushing, shoving, hitting, and beyond.[iv] Using cross-sectional analyses within a later wave of their longitudinal Toledo adolescent relationships study—involving 926 individuals aged 22-29—Manning and colleagues found that cohabiting couples were more likely to report aggression (31 percent) in their relationship than married (23 percent) or dating couples (18 percent). These differences held even when controlling for many other variables.[v]
Similarly, in our relationship development study, a national, longitudinal sample of 1,278 emerging adults in unmarried relationships (aged 18 to 34), we found that 48 percent of the unmarried adults reported some sort of physical aggression in the history of their relationship. The percentages in our sample are likely higher due to the wider age range and other differences. While the percentages in these studies may seem high to you, they are consistent with many other studies of those in these earlier stages of life.[vi]
In our study, we focused on the odds that people who reported aggression in their romantic relationships would break up in the future. We found that those who reported aggression in the prior year were more likely to break up in the next two years (37 percent), compared to those reporting no aggression (27 percent) or aggression that occurred more than a year in the past (30 percent).
The latter two groups were not significantly different in the likelihood of remaining together. We also found that those who were living together—compared to dating and not living together—were more likely to report that their relationship experienced physical aggression within the prior year. Among those with aggression, the odds were five times greater that they would remain together over the next two years if they were cohabiting versus dating (even when controlling for a number of other important variables).[vii]
Hitting is especially common in relationships during earlier stages of life. Even though many break up, it raises the question of why so many of these couples stay together—a subject addressed by the focus on commitment in both papers we describe here.
There are many different published theories of commitment in romantic relationships. The one we like to use most is from the early 1990s by Stanley and Markman, which was informed by the theoretical and empirical work of many luminaries across disciplines and decades. Some of the notables include John Thibaut and Harold Kelley, Peter Blau, George Levinger, Michael Johnson, Karen Cook and Richard Emerson, and Caryl Rusbult.[viii]
Stanley and Markman provide for a straightforward way of thinking about why relationships continue or have certain qualities by dividing commitment into the dimensions of dedication and constraint.[ix] Dedication reflects the desire to be with a person in the future, to form an identity as a couple, to sacrifice for and prioritize the relationship. Dedication can lead you to doing the right or best thing for your partner and the relationship, now and in the future. What we call dedication often goes by the simple name of “commitment” in much of the literature where commitment is measured relatively well.[x]
In contrast to dedication, constraint commitment is comprised of a collection of relatively disparate dimensions that reflect both past investment in the relationship and factors that make it harder to leave—if one wanted to do so. Constraints come in many forms, and they play a complicated role in the maintenance of relationships. Sometimes they reflect investments (that can be lost),[xi] and sometimes they reflect options that are limited or have become more so. In either case, what constraints do, conceptually and empirically, is raise the costs of leaving and reinforce staying, net of dedication.[xii] Constraints are not all that important in a person’s day-to-day relationship experience unless dedication is burned away; when dedication is gone, it is constraint commitment that can keep you where you are at.
Here are two examples: You have more constraint commitment to stay on your current path (in any area of life, not just relationships) when you have fewer alternatives to it. One type of alternative relates to your perception of how available other desirable partners would be if your present relationship ended. Another type of constraint is financial. For example, if you’ve invested more—bought more together, combined accounts, etc.—you have more to lose if you break it off. There are many other types of constraints. Some are easily seen as evidence of past dedication and some are built into a person’s life before they meet their present partner.
Those who follow our work closely will recognize in these themes why we believe that cohabitation matters (especially before commitment to a future is clear and mutual). While it’s become easy to have positive perceptions about the benefits of cohabiting prior to, or instead of, marriage, what people often fail to recognize is that cohabiting also increases constraints to remain together before dedication has become clear or matured.[xiii] This is what we refer to as the problem of “inertia.”[xiv]
The Interplay of Dedication and Constraint in Relationships with Aggression
In both studies discussed in this post, dedication and various dimensions of potential constraint were analyzed. In their study, Manning and colleagues found that dedication was associated with lower odds of being in a relationship with aggression, as did we in our earlier research. There are at least a couple of reasons why this is so. First, people are generally going to be less committed to a relationship with aggression. Second, studies show that commitment (think of dedication) inhibits negative behaviors, including aggression,[xv] which would partly explain why people who are more dedicated to their partners report less of it.
The two studies we describe here also found that relationships with more aggression tended to have lower dedication and higher constraints. This is about what you would expect. Additionally, Manning and colleagues found that the high-constraint/low-dedication combination was more common for cohabiters than marrieds or daters.
Both studies contain nuances that make the interpretation about cohabitation and commitment complex. For example, while Manning and colleagues found that both dedication and constraint were associated with aggression, as we just noted, they did not find that these commitment dynamics explained why cohabitation was more associated with aggression than marriage or dating.
We also found that living together was strongly associated with the likelihood that relationships with a history of aggression would continue, even while taking into account measures of constraint, overall relationship quality, and dedication. Based on the idea of inertia, you might expect that controlling for some aspects of constraint would lower the degree to which cohabitation was associated with aggression; but living together remained associated with aggression—and with aggressive relationships continuing.
Selection, Inertia, and Asymmetrical Commitment
Do the increased constraints of cohabiting make it more likely that people in aggressive relationships will remain in those relationships, or is something else in the mix? All of these findings are consistent with the fact that there is a lot of selection for risk in cohabiting relationships that lack a clear, mutual commitment to marriage (or at least, a future). That is, some people are at greater risk than others for virtually every negative relationship outcome you can think of because of factors related to their history, their family, their genetics, or their economics. And people already at greater risk are more likely to cohabit in the ways associated with the most risk (e.g., with a number of partners and/or before there is a serious, mutual commitment to marriage). We believe that cohabitation is a particular problem for some people because it increases the odds that a relationship already selected for greater risk will continue—or continue longer than it otherwise would have. We have shown that moving in together increases constraints and also that constraints make it more likely one will remain in a relationship net of dedication.[XiV & XV]
In total, these studies make a great deal of sense. What may be missing in them, however, is another dimension we think a lot about—asymmetrical commitment.
The two samples for the studies described in this post included individuals rather than couples. They do not have measures of commitment from both partners, just the one. We have evidence that cohabitation without (or before) engagement or mutual plans to marry may be—in a way—a magnet for couples where one partner is substantially less dedicated than the other. We recently wrote about asymmetrically committed relationships, describing research where commitment levels of both partners are assessed. We found that asymmetrical commitment is more likely to exist in cohabiting couples than dating relationships and, among marrieds, it is more likely to exist when couples lived together prior to engagement or marriage. While some of these relationships epitomize higher constraint and lower dedication, what matters most for this next point is that the levels of dedication are not mutual.
Asymmetrical commitment may be one ingredient in the way cohabitation and aggression are linked. We have found that asymmetrically committed relationships are more prone to aggression and generally have low relationship quality.[xvi] Many asymmetrically committed relationships contain one partner who is not committed enough to inhibit negative behaviors and another who, while relatively highly committed, will be massively frustrated by a growing awareness of their partner’s lower commitment. That sounds like a recipe for highly destructive conflict.
Many relationships involve aggression, especially in the earlier stages of life. While it is common and it comes in many forms, aggression in intimate relationships is unsafe and carries the potential for lasting harm. The most dangerous patterns involve aggression that leads to injuries and/or ongoing control and intimidation.[xvii] In contrast, individuals thrive in life and succeed in relationships when they have emotional and physical safety with the security of mutual commitment.