The Science of Cohabitation: A Step Toward Marriage, Not a Rebellion

New research shows that the older people are when they make their first big commitment—cohabitation or marriage—the better their chances for marital success.

As more and more American couples choose to share the bills and a bed without a marriage license, a major question looms. In playing house and stocking up on premarital Ikea furniture are we all heightening our risk for divorce?

A new study from the nonpartisan Council on Contemporary Families says no. Moving in before marriage doesn’t automatically make you a divorce statistic. Choosing a partner too early, however, just might.

The study, which will appear in the in the April issue of the Journal of Marriage and Family, could redefine how researchers look at cohabitation, but the science shouldn’t change the way couples think about living together. Experts warn it’s hardly something to be taken lightly.

Arielle Kuperberg was a graduate student at the University of Pennsylvania when something in her sociology textbooks caught her eye. In research on marriage longevity, Kuperberg observed that the age a couple said “I do” was among the strongest predictors of divorce.

All of the literature explained that the reason people who married younger were more likely to divorce was because they were not mature enough to pick appropriate partners, she says.

That’s when a lightbulb went off for Kuperberg. If younger married couples were more likely to divorce, did that mean that couples who moved in together at earlier ages were also at increased risk for broken marriages?

Other researchers who had been exploring the link between cohabitation and divorce failed to take into account the age at which couples took that plunge. Kuperberg wondered if once she controlled for age, the link between cohabitation and divorce might disappear.

Using data from the U.S. governments’ 1995, 2002, and 2006 National Surveys of Family and Growth, Kuperberg analyzed more than 7,000 individuals who had been married. Some of the people she studied were still with their spouse. Others were divorced. Then, instead of studying just the correlation between cohabitation and divorce, Kuperberg looked at how old each individual was when he or she made his or her first major commitment to a partner—whether that step was marriage or cohabitation.

Moving in together without a diamond ring involved didn’t, on its own, lead to divorce. Instead, she found that the longer couples waited to make that first serious commitment, the better their chances for marital success.

So how old should couples be when they commit? The research shows that at 23—the age when many people graduate from college, settle into adult life and begin becoming financially independent—the correlation with divorce dramatically drops off.

Kuperberg found that individuals who committed to cohabitation or marriage at the age of 18 saw a 60 percent rate of divorce. Whereas individuals who waited until 23 to commit saw a divorce rate that hovered more around 30 percent.

“For so long, the link between cohabitation and divorce was one of these great mysteries in research,” Kuperberg says. “What I found was that it was the age you settled down with someone, not whether you had a marriage license, that was the biggest indicator of a relationship's future success.”

Cohabitation has become so common that it’s almost odd not to test drive a partner before marriage. It’s worthy of a People magazine headline now when a celebrity couple “waits until marriage” to shack up. Bachelor Sean Lowe (of ABC’s The Bachelor) and his wife Catherine Giudici were all over the tabloids when they announced they would not move in together until after their televised wedding.

Cohabitation has increased by nearly 900 percent over the last 50 years. More and more, couples are testing the waters before diving into marriage. Census data from 2012 shows that 7.8 million couples are living together without walking down the aisle, compared to 2.9 million in 1996. And two-thirds of couples married in 2012 shared a home together for more than two years  before they ever waltzed down an aisle.

Today, discussing cohabitation is about as salacious as watching grass grow. A 2007 USA Today/Gallup poll found that just 27 percent of Americans disapproved of it. The number of painful discussions I personally endured two years ago when I moved in with my own boyfriend can be counted on one hand. My fridge is littered with wedding announcements from couples who are engaged and lived together for years.

Yet the science of cohabitation has largely carried a “toxic for marriage” warning label. From Annie Hall to Friends to Girls, it seems everybody has been moving in with their significant others, but science told us it was hardly a good idea.

Since the 1970’s, study after study found that living together before marriage could undercut a couple’s future happiness and ultimately lead to divorce. On average, researchers concluded that couples who lived together before they tied the knot saw a 33 percent higher rate of divorce than those who waited to live together until after they were married.

Part of the problem was that cohabitors, studies suggested, “slid into” marriage without much consideration. Instead of making a conscious decision to share an entire life together, couples who shared a dog, a dresser, a blender, were picking marriage over the inconvenience of a break up. Meg Jay, a clinical psychologist, outlined the “cohabitation effect” in a widely-circulated New York Times op-ed in 2012.

“Couples who cohabit before marriage (and especially before an engagement or an otherwise clear commitment) tend to be less satisfied with their marriages—and more likely to divorce—than couples who do not,” she wrote.

Others blamed the types of individuals who were moving in together as the reasons so many of those unions resulted in divorce.

“Back in the 1960’s, the 70’s, and the 80’s, cohabitation was a more unconventional way of getting together. The types of people who were cohabiting were less likely to conform to the traditional standards of marriage such as responsibility, fidelity, and commitment,” says Bradford Wilcox, the director of the National Marriage Project at the University of Virginia.

In the 1960’s, television and movie storylines steered clear of cohabitation. Everywhere women were warned that “giving the milk away for free” could result in lifetime of spinsterhood when nobody wanted to “buy the cow.” According to the National Marriage Project  fewer than 500,000 unmarried couples were living together in the U.S. in the early 1960’s. In her 2013 book Not Just Roommates, Elizabeth Pleck explored how many states kept laws on the books to prohibit cohabitation in the 20th century and even keep interracial couples apart. It took a more free-thinking individual to violate the moral standards depicted in shows like Leave it To Beaver and The Brady Bunch. It took a risk taker to sit down at the kitchen and tell their parents that they were moving in with their girlfriend or boyfriend. Researchers believed that the types of couples who chose to live together before marriage were rebels who held “less conventional” views about the sanctity of the institution.

Now, Wilcox argues that cohabitors represent a broader swath of the public. Many more couples view cohabitation as a step toward marriage, not a rebellion against it.

A Pew Research study in 2011 found that more than 60 percent of Americans who had ever lived with a partner before marriage saw their living situation as a precursor, not an alternative, to wedded bliss.

It’s still true that cohabitation isn’t without its risks. Experts warn that waiting for an appropriate age to commit to someone is still no substitute for communication.

Jay, who has also written a book about Millennials called The Defining Decade:Why Your Twenties Matter- And How to Make the Most of Them warns that the most recent cohabitation study still does not prove that couples understand the gravity of moving in together, nor does it show that cohabitation is a “silver bullet” to stop divorce.

“Living together doesn’t charm or doom you; it is not whether you live with your partner as much as how you live with your partner,” Jay said. “I am not against living together, but I am for young adults being more aware that it is an arrangement that has upsides and downsides.”

Couples who live together before marriage enjoy a companion and a teammate, but sometimes, Jay warns, couples stay in relationships longer than they should because once they live with someone, it can be harder to find the escape hatch.

“I have clients who say ‘I spent years of my 20s living with someone who I wouldn’t have dated a year if we had not been living together,’” she says, adding, “Once you buy dishes, share a lease, have a routine, and get a dog, it can be difficult to cut your losses and accept that the relationship isn’t working.”

The risks of unplanned pregnancy are also increased for women who chose to live with their partners before marriage. In a 2013 report, the Centers for Disease Control and Prevention found that 20 percent of women cohabiting for the first time became pregnant  and had a baby within one year of moving in with a boyfriend. That number was up 5 percentage points from 15 percent in 1995.

“Cohabitation fosters enough intimacy to facilitate childbearing but not enough commitment to make people deliberate about their choices to become parents,” Wilcox says. “The result, an unplanned birth, can pose real problems to their relationship and to their future odds of successfully marrying.”

The latest research should give older couples a sense of relief. The science is beginning to show that peeking behind the curtain before choosing to settle into a lifetime of marriage isn’t in and of itself a mistake, but there are still risk factors. It might be important today for all of us to know whether our partner handles the dirty dishes, but cohabitation can still be a mess for those who don’t proceed with caution.