In the last 50 years, more and more people have started living together outside of commitment to marriage. In fact, 60 percent or more of couples now live together before they get married and many others live together instead of getting married. The rates of living together are even higher for remarriages. Many believe that living together is a good way to “test” the relationship, or give it a trial run. Perhaps because they are either wary of commitment or have particular reasons to be concerned about their relationships, many think they will learn things about their relationship that will help them decide whether to commit to marriage with a particular partner.

The majority of young adults do believe that living together helps people make decisions about marriage as well as provides a way for couples to work through issues before making a lifelong commitment. In fact, over half of younger people believe that living together prior to marriage will lower their odds of marital problems and divorce.¹ Research, however, suggests something quite different.

• People who lived together before marriage have a higher rate of divorce than those who did not live together.
• People who lived together before marriage report that it is more likely they will divorce than people who did not live together.
• People who lived together before marriage have more negative communication in their marriages than those who did not live together.
• People who lived together before marriage have lower levels of marital satisfaction than those who did not live together.
• Infidelity during marriage is more common among people who lived together prior to marriage than those who did not.
• Physical aggression is more common among married individuals who lived together before marriage than those who did not.

There are always exceptions to any research findings, but there are many studies documenting these important differences. ²

Why Does Living Together First Often Result in Negative Outcomes?
Some people believe there is something important about the experience of cohabitation that relates to a higher risk of divorce (the experience theory). What might that “something” be? Well, some have found that people’s attitudes about marriage and childbearing change— become more negative—after living together.³ So, it could be that living together makes people less interested in marriage and less interested in having children. However, others have speculated that when people live together they develop a mindset in which they think, “Well, if this doesn’t work, I can easily get out.” The problem is that this mindset might not change when the couple gets married, making it easier for them to divorce.

Other experts believe that it’s not actually the experience of living together that relates to poorer outcomes over time, but rather that people who live together before marriage already have characteristics that put them at risk for divorce and unsatisfying marriages (the selectivity theory). A host of research indicates that there are important differences between the backgrounds of people who live together before marriage and the backgrounds of those who don’t.

Our main theory, which we call the inertia theory, is simple. It suggests that external pressure to remain together starts to build when a couple moves in together. You move in together, buy a place, get a dog, spend less time with friends and more time alone together, and maybe declare the other as your beneficiary for financial matters—and these things make it more likely that you will stay together. In other words, there is an increasing weight of forces that favor your staying together when you live together. In the words of Scott’s commitment theory, living together increases the constraints of leaving the relationship.

Something that too few people recognize is that it’s hard to end a relationship with someone when you share things like a home, possessions, and friends. We chose inertia to describe our theory because it implies that partners who are living together may stay in their relationship, on a path toward marriage, unless a major force derails them.

Here’s an example. Todd and Lorraine were in their mid- twenties when they met. They dated for a few months and when Lorraine’s lease ran out, she moved into Todd’s place. I’m spending most of my time with Todd anyway, Lorraine thought, and she already kept many of her clothes and other things at his place.

When she moved in, she and Todd signed a new one-year lease together and she paid for half the deposit. Then they decided to get a puppy. And when Todd’s car broke down, it seemed to make sense for him and Lorraine to buy a car together. She provided the down payment and then they split the monthly payments.

All of these seemingly minor steps would make it harder for Todd and Lorraine to end their relationship if either decided that was what he or she would prefer to do. If they each kept their own place and dated exclusively and regularly, it might be painful to end the relationship but far easier than it would be once they started living together.

The key thing to think about here, though, is what is happening with commitment. If Lorraine and Todd already know they are dedicated to each other and to marriage in the future, especially if they are engaged, then the pressures to stay together that come with living together will not really affect their path. It won’t be why they end up marrying. Living together may increase some of their other risks, such as eroding their belief that marriage illustrates the highest form of commitment, and that’s not good. But living together would not make it more likely than it already was that they would marry.

But let’s change the possibilities. Suppose Todd and Lorraine are very emotionally attached but not at all clear about their future. In fact, suppose that, while attracted and interested, they each have some concerns about their relationship (say, they argue a lot and sometimes these fights nearly get physical) or about one another (perhaps Todd drinks a little too much or Lorraine has serious problems holding onto a job). Now it’s a very different story. Sure, they are living together because they want to spend more time together, but it’s also because they want to test the relationship.

[The inertia theory suggests that couples who are at the greatest risk are those who are in love but aren’t sure they want a future together—people don’t realize that it’s much harder to break off the relationship once they move in together. Further, more couples than ever before have children (planned or not) when they live together, so that makes it even more gut wrenching to contemplate ending the relationship.]

Let’s look at another scenario involving a couple in their mid- twenties. After a few months of dating, Greta’s lease ran out and Dan casually asked her to move in to save money. She agreed. As is very often the case, this couple didn’t talk seriously about the decision to move in together; it “just sort of happened.”⁴ They started living together without a clear plan to marry.

But now that they are living together, Greta isn’t so sure she wants to be with Dan for the long haul. He drinks more than she does and he likes to go out with friends and party. They argue a lot about money. Still, Greta tells herself, it’s fine for now.

Nine months later, Greta is getting fed up. She has realized she wants to get married and start a family, but Dan has said he’s not ready. They start arguing even more. Greta wants to break up, but decides to wait until the lease is up. She doesn’t want to make things difficult for Dan and it’s going to be hard for her to afford a place on her own. But just before the lease is up, things get a little better between them and Greta unexpectedly gets pregnant. Once she is pregnant, she really wants to get married, and Dan eventually agrees.

Unlike in the previous scenario, the risks of living together here are important. That’s because this couple probably would not have gotten married if they hadn’t lived together. Constraints have propelled them forward, not dedication.

[Greta and Dan are a perfect example of something I think happens way too often: people marrying because they were living together and even though the man never fully committed to the woman before he lost his options. I call these “maybe I do” marriages because the couples do not express a clear “I do” on their wedding day, rather a “maybe I do.” My advice here, to both women and men, is that if you have to drag your partner to the altar, it is probably an indication of many draggings to come. A mate who commits reluctantly does not make for a great marriage.

When you live together prior to marriage or engagement, you are giving up options before you’ve clearly made your choice. Life almost never turns out as well when you give up options before choosing.]

Mate Selection 101
Surprisingly, marriage scholars and researchers have not devoted a great deal of attention over the past decades to good mate selection. Sociologist Norval Glenn at the University of Texas has noted that this is a serious gap in the field, and I think he is right. There are surely useful studies in this area, but people have not been given enough guidance about how to make a good choice.⁵

Here's a very simple list based on many years of research, many years of counseling couples, and reading and thinking about this issue. The more of these things you are able to do when you are searching for a mate and thinking about marriage, the better your odds will be of making a wise choice.

• Get to know the person very well before deciding to marry. One thing you can do is take the time to work together through a detailed list of core expectations to see just how compatible you are. (For guidelines on how to do this, you might check out one of the books I’ve co- authored.⁶)
• Do not make this crucial decision in a period of emotional infatuation.
• Date the person for a long time.
• Observe how the person treats not only you but his or her friends. Learn as much as you can about the person’s priorities and values.
• Give more weight than your heart may want to how closely the person shares your most essential beliefs (including religious) and values in life.
• Wait until you are 22 or older to make such an important decision. What you think you are looking for can change a lot.
• Get the opinion of friends and family who are not likely to tell you only what you want to hear.
• Wait until you are married to live together. It may not increase your risk to do otherwise, but there is no evidence that it will increase your risk to wait.