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Definition: cohabitation from Collins English Dictionary


1 the state or condition of living together in a conjugal relationship without being married

2 (of political parties) the state or condition of cooperating for specific purposes without forming a coalition

Summary Article: Cohabitation
From Encyclopedia of Human Relationships

Cohabitation refers to partners in a romantic relationship who are living together without being married. Although this definition seems straightforward, there is some confusion in the research literature and among people in general as to what specific living arrangements are considered cohabitation. Are partners who have separate apartments but who spend most nights together cohabiting? If a couple first began living together as friends or roommates, are they cohabiting once their relationship becomes romantic? For the purposes of this entry, cohabitation will refer to unmarried romantic relationships in which partners share a single address without having separate residences. Thus, the answer to the first question would be no, but to the latter, it is yes.

Demographics of Cohabitation

The recent decades have seen a dramatic increase in cohabitation in the United States, as well as in Canada and in many Western European countries. The following statistics are from the United States, though many of these trends apply to other countries, too. From 1960 to 2000, there was more than a tenfold increase in the number of cohabiting couples. Further, around 70 percent of couples live together before marriage. These figures coincide with other notable changes with regard to marriage in the United States, including a rise in divorce rates over the past 5 decades (though they have leveled off more recently) and a later and later average age for first marriage.

Many cohabiting couples have children, whether their own or from previous relationships. As many as 40 percent of cohabiting couples have children residing with them, and 20 percent of children born in the 1990s will reside in a cohabiting household at some point while growing up.

Many studies in the United States, and in some other countries, find that couples who cohabit prior to marriage are more likely to have difficulties in their marriages and to divorce. This phenomenon has been somewhat of a mystery for social scientists, and something that is barely believable to the average person. After all, most people, especially young people, assume that trying out living together should improve the odds of doing well in marriage. Yet no study supports this idea. On average, those who cohabit prior to marriage are more likely to divorce, are less happy in their marriages, have higher levels of conflict, and have less confidence about their futures. This association with poorer outcomes in marriage is called the cohabitation effect. Like any other area of research, such findings are about what happens on average; there are many couples who would be exceptions to the general trend. Many couples who cohabit beforehand have fine marriages, and many couples who do not cohabit end up divorcing. Yet, on average, the data consistently show a higher risk associated with cohabitation. Although some social scientists expected that higher risks would no longer be found once cohabiting was more widely accepted, the newest studies continue to show the cohabitation effect.

Selection Versus Experience

The fact that the cohabitation effect occurs is not disputed among social scientists. What is debated is why it occurs. There are two fundamental explanations: selection and experience. Selection effects are characteristics of people that make them more likely to behave in certain ways. These behaviors then might be related to a particular outcome. For example, a study may find that eating more celery is linked with living longer. Would this finding suggest that all of us should be on a high-celery diet? Not really. Such a finding would have more to do with the fact that those who eat more celery also tend to have more vegetables and less fat, overall, in their diets. The result would be less about celery and more about the other characteristics of those who eat celery.

There are a number of ways in which people who cohabit before marriage differ from those who do not. For example, those who do not cohabit tend to be more traditionally religious and are more likely to have parents who stayed married. People who are more religious are somewhat more likely to have successful marriages, and those with divorced parents are more likely to struggle in their own marriages. Thus, people who are less at risk for difficulties in marriage are less likely to cohabit prior to marriage in the first place. The selection perspective argues that such risks are present before cohabiting and that there is nothing about the experience of cohabitation itself that causes divorce.

Does selection explain the cohabitation effect? A number of researchers have begun to question if the cohabitation effect can be explained entirely by selection. If selection does not explain it fully, what else might? One answer found by some researchers is that cohabiting prior to marriage with more partners, or for longer periods of time with one partner, is associated with a change in attitudes about marriage. Essentially, people start to value marriage (and having children) less the more they cohabit. This research suggests that the experience of cohabiting erodes values about marriage and family. In turn, valuing marriage less could increase one's risk for divorce.


Scott Stanley, Galena Rhoades, and Howard Markman have suggested an experience-based perspective for the cohabitation effect that provides an intuitive explanation. Based on prior work in the area of commitment theory, they note that no matter what else may be true, it is harder to break up when cohabiting than when dating. It is harder to exit a relationship when exiting means partners have to divide up property or friends, move possessions, break a lease, or give up a pet. It could be as emotionally difficult to break up when seriously dating as when cohabiting, but there are all these extra constraints to breaking up when two people cohabit—especially if neither partner has another place that is readily available. In essence, these researchers argue that there is stronger inertia in cohabiting than in dating. In physics, inertia represents the amount of energy it takes to move an object that is at rest or to change the direction of an object already moving. About 50 percent of cohabiting couples break up instead of marrying, but breaking up is likely harder for them than it is for dating couples.

This theory of inertia suggests that cohabiting might lead some poorly matched partners to marry, even though they would not have chosen to marry if they had not already been living together. There is already considerable evidence for this notion that inertia explains some of the cohabitation effect. For example, inertia suggests that some cohabiting couples stay together because it becomes too hard to break up; those who began cohabiting only after they were already engaged cannot be as likely to marry because of inertia as couples who started cohabiting before they committed to marriage. Some research suggests that couples who cohabit only after becoming engaged are at no greater risk for marriage difficulties than those who do not cohabit at all before marriage. Based on the available evidence, it will make sense to some couples to wait until marriage to live together. For other couples who intend to cohabit, it looks like it is particularly important for the two partners to make a mutual decision about the future before they limit their options through the constraints and inertia associated with cohabitation.

Sliding Versus Deciding

The theory of inertia emphasizes the nature of relationship commitment at the beginning of cohabitation. Couples who are clearly and mutually committed to marriage when they move in together are less likely to experience the cohabitation effect. But how do most couples begin to cohabit? Researchers Wendy Manning and Pamela Smock have conducted extensive interviews with couples who are cohabiting in the United States. They find that virtually no couples talk about the transition into cohabiting. Rather, most slide into cohabitation. They rarely discuss the meaning of the change or their levels of commitment to each other first. Stanley and colleagues hypothesize that, for all kinds of major relationship transitions (e.g., having sex for the first time, becoming pregnant, cohabiting), sliding is associated with more risk than deciding. The paradoxical risks of cohabiting prior to marriage continue to be studied by numerous research teams, which should mean the cohabitation effect will be increasingly well understood in the years to come.

Cohabitation Versus Marriage

Because more couples than ever before cohabit instead of or before marriage, researchers have studied differences between married and cohabiting couples. This comparison is far harder to make than one might think. For example, married couples tend to have been together much longer than cohabiting couples. On the one hand, because most couples tend to experience a decline in happiness over time, comparisons between long-time married couples and cohabiting couples would be biased in favor of showing cohabiting couples to be, on average, happier. On the other hand, couples who make it through many years of marriage are a special group, having survived many difficult and challenging times together. Therefore, samples of long-time married couples tend to include many very happy couples. This is just one example of how difficult it is to properly compare cohabiting versus married couples. Nevertheless, after carefully accounting for the complex nature of this comparison, researchers have found several important differences between cohabiting and married couples.

Generally, cohabiting couples tend to look more like dating couples than married couples on various measures. All other things being equal, individuals who are cohabiting tend to report less satisfaction with their relationships, lower levels of dedication (a type of commitment) to their partners, and more problems with infidelity. They also tend to have more problems with alcohol and depression than people who are married.

The growing trend for couples to cohabit rather than marry, or cohabit prior to marriage, has changed the landscape for how couples and families form. Although most research has focused on first marriages, this phenomenon extends to post divorce unions as well as elderly and widowed adults who may choose to cohabit rather than marry to avoid comingling finances or upsetting family members. There will be much future research on the nature, meaning, and effects of cohabitation because it has become such a prevalent part of couple and family development.

See also

Commitment, Predictors and Outcomes, Dating Relationships in Adolescence and Young Adulthood, Marriage, Benefits of, Marriage, Transition to

Further Readings
  • Axinn, W. G.; Barber, J. S. Living arrangements and family formation attitudes in early adulthood. Journal of Marriage and Family 59 ((3)) : 595-611., 1997.
  • Brown, S. L.; Booth, A. Cohabitation versus marriage: A comparison of relationship quality. Journal of Marriage and Family 58 ((3)) : 668-678., 1996.
  • Bumpass, L. L.; Lu, H.-H. Trends in cohabitation and implications for children's family contexts in the United States. Population Studies 54 ((1)) : 29-41., 2000.
  • Cohan, C. L.; Kleinbaum, S. Toward a greater understanding of the cohabitation effect: Premarital cohabitation and marital communication. Journal of Marriage and Family 64 ((1)) : 180-192., 2002.
  • Kamp Dush, C. M.; Cohan, C. L.; Amato, P. R. The relationship between cohabitation and marital quality and stability: Change across cohorts? Journal of Marriage and Family 65 ((3)) : 539-549., 2003.
  • Kline, G. H.; Stanley, S. M.; Markman, H. J.; Olmos-Gallo, P. A.; St Peters, M.; Whitton, S. W. Timing is everything: Pre-engagement cohabitation and increased risk for poor marital outcomes. Journal of Family Psychology 18 ((2)) : 311-318., 2004.
  • Manning, W. D.; Smock, P. J. Measuring and modeling cohabitation: New perspectives from qualitative data. Journal of Marriage and Family 67 : 989-1002., 2005.
  • Smock, P. J. Cohabitation in the United States: An appraisal of research themes, findings, and implications. Annual Review of Sociology 26 : 1-20., 2000.
  • Stanley, S. M.; Rhoades, G. K.; Markman, H. J. Sliding vs. deciding: Inertia and the premarital cohabitation effect. Family Relations 55 : 499-509., 2006.
  • Stanley, S. M.; Whitton, S. W.; Markman, H. J. Maybe I do: Interpersonal commitment and premarital or nonmarital cohabitation. Journal of Family Issues 25 ((4)) : 496-519., 2004.
  • Stanley, Scott M.
    Rhoades, Galena K.
    Copyright © 2009 by SAGE Publications, Inc.

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