The Cohabitation Effect: Should You Live Together?

This article is an excerpt from the Shortform book guide to "The Defining Decade" by Meg Jay. Shortform has the world's best summaries and analyses of books you should be reading.

Like this article? Sign up for a free trial here.

What is the cohabitation effect? What is its effect on relationships?

The cohabitation effect is when a couple cohabitates without making a strong commitment or begins cohabiting by accident. The cohabitation effect can have negative consequences for relationships.

Read more about the cohabitation effect below.

What Is the Cohabitation Effect?

Many young adults think that living with a partner before marriage will allow them to “try out” a marriage before committing and will result in a stronger union. Unfortunately, the statistics don’t back this up: Couples who live together are more likely to divorce down the road than those who do not. This is called the “cohabitation effect” and it has baffled researchers for years.

Some researchers theorize that those who cohabitate may be less conventional and open to divorce in the first place, but the cohabitation effect appears to be true regardless of religion, education, or political leanings. The effect seems to be more a result of the fact that when people cohabitate, they often end up passively and reactively sliding toward a marriage, rather than proactively deciding on one. When this happens, a couple often ends up staying together because of sunk costs and ultimately separates because they never truly understood a marital relationship or they were never right for each other in the first place.

People Stay Because of Sunk Costs

When two people decide to move in together, it’s often touted as an easy solution to short-term challenges like rent. Moving in together seems fun and cost-effective, and feels like an easily-escapable arrangement, unlike marriage. And it might be, at first. But after combining lives for a while, leaving the situation can actually feel quite difficult, and a couple may feel it’s easier to stay in a relationship because of the sunk costs of the arrangement. 

When you make an initial investment in a relationship, the “switching costs” feel hypothetical and far away. But after some time passes, the costs feel bigger and more real. You may have shared pets, passwords, and finances that are harder to walk away from. This is known as “consumer lock-in,” and it describes the fact that people are less likely to look for other options once they’ve made an investment in a first option. 

You also may be older, and the idea of starting over can feel more daunting at 32 than it felt at 27. Instead of cutting your losses, you may opt for marriage because it feels like it makes sense given the investments you’ve already made in the relationship. In a word, you feel stuck. 

People Don’t Fully Understand Marriage

People often move in together under the pretense that they are giving marriage a trial run, but in truth, a live-in relationship has little resemblance to a marriage. Stresses like mortgages, pregnancies, child-rearing, holidays with in-laws, college and retirement plans, and bills often don’t exist during cohabitation but can destroy a marriage. Once a relationship transforms from live-in to married, these stresses can break it. 

A Couple May Be Poorly Matched From the Start

Often people slide from dating to sleeping over to moving in without fully examining the relationship. The process is driven by short-term impulses—fun weekends, cool friends, good sex, shared rent—that may not have been what either one would have looked for in a long-term partner. 

Because cohabitation feels more easily escapable than marriage, both men and women agree that they have lower standards for a live-in partner than for a spouse. Interestingly, the cohabitation effect does not hold for couples who move in together after becoming engaged. These couples are as likely to stay together as are couples who don’t cohabitate before marriage. The effect seems to be entirely caused by people moving in with right-now partners who end up becoming, unintentionally, more permanent partners, for the wrong reasons. 

This is not to say you should absolutely not cohabitate before marriage, but if you are considering doing so, don’t make the decision lightly:

  • Lean towards not doing it.
  • Get clear about the other person’s long-term goals and commitment level before you move in. 
  • Keep an eye on the costs of leaving. Regularly check in on the constraints keeping you in the relationship and make sure they don’t get so burdensome that you would be unable to walk away. 
The Cohabitation Effect: Should You Live Together?

———End of Preview———

Like what you just read? Read the rest of the world's best book summary and analysis of Meg Jay's "The Defining Decade" at Shortform.

Here's what you'll find in our full The Defining Decade summary:

  • Why the twenties are your most important decade
  • How you were fooled into thinking it was an extended period of youth and freedom
  • Why you should use this decade to find personal and professional success

Carrie Cabral

Carrie has been reading and writing for as long as she can remember, and has always been open to reading anything put in front of her. She wrote her first short story at the age of six, about a lost dog who meets animal friends on his journey home. Surprisingly, it was never picked up by any major publishers, but did spark her passion for books. Carrie worked in book publishing for several years before getting an MFA in Creative Writing. She especially loves literary fiction, historical fiction, and social, cultural, and historical nonfiction that gets into the weeds of daily life.

Leave a Reply

Your email address will not be published. Required fields are marked *