Med thumb apartment key

Cohabitation is in. In most parts of America, moving in with a partner before marriage is seen as a perfectly acceptable step in the life cycle of a modern relationship, rather than as the Paperless Post to Satan it once was. According to Council on Contemporary Families, cohabitation has increased by nearly 900 percent in the past 50 years, with nearly 8 million couples living together before putting a ring on it. In fact, 70 percent of women aged 30 to 34 have lived with a male partner, and two-thirds of new marriages take place between couples who have already lived together for an average of 31 months.

Why not take a potential life partner for a domestic test-drive before you’re locked in to a lifetime lease, many ask, using what might be the least affectionate metaphor ever for a beautiful bond. But sometimes it pays to know if the airbags are going to work in the event of a collision and whether you’re more of a manual or an automatic. (And while we’re beating this analogy to death: Never opt for the undercoating.)

Yet, despite the commonality and common sense of the practice, we still hear outcries from those who believe that living together before tying the knot is toxic. For some it’s a matter of religion; for others it’s a matter of science; and for others, the nervousness stems from old Billy Joel songs about a doomed couple named Brenda and Eddie. In any case, many believe bunking up is bad for the future.

Research backs them up. Sort of. In the cohabitation boom of the 1970s, studies said moving in together doomed a marriage. Many of these studies are now antiquated, but more recent research plays the same note.

Consider, for example, a 2009 study from the University of Denver conducted by psychologist Galena Rhoades. When cohabitating couples did marry, Rhoades found, they were likely to be unsatisfied and at risk of divorce. Rhodes surmised that, if not for cohabitating, these couples wouldn’t have agreed to get married. Sociologists call it the inertia effect — couples move forward because they sense the trajectory of their lives. In other words? No one wants to roll out of a moving car.

For some it’s a matter of religion; for other, science; and for others, the nervousness stems from old Billy Joel songs about a doomed couple named Brenda and Eddie.

Of course, this doesn’t tell the entire story. Many factors are involved, particularly the age at which couples say “I do.” A 2014 study from the Council on Contemporary said that it’s not the act of moving in before marriage that increases the risk of the divorce, but rather the age of the cohabitating couple.

Arielle Kuperberg, assistant professor of sociology at the University of North Carolina Greensboro, used data from national surveys to analyze more than 7,000 married and divorced individuals. She then looked at the average age of each couple when they cohabitated, and compared that number to the divorce rate.

She found that 23 is the magic age for smart cohabitation, as those who moved in or were married by the age of 18 were 60 percent more likely to end up divorced. Among those who moved in at 23, the likelihood dropped to 30 percent.

So why the discussion over concern for cohabitation? A new study from Ohio State University outlines the merits of moving in. The study, published online in the Journal of Family Psychology, says that young couples, especially the women, are just fine moving in together before marriage. In fact, it boosts mental wellbeing.

The researchers looked at a mass of data collected throughout the 2000s and studied the happiness levels of cohabitating and married couples. They discovered that “single young women experienced a similar decline in emotional distress when they moved in with a romantic partner or when they went straight to marriage for the first time,” per a release.

Men, too, experienced a drop in the sads, but only “when they went directly to marriage.” When they moved in with a partner for the first time, men experienced no increase of happiness.

Per the release, associate professor of humans sciences and lead researcher Claire Dush said the study affirms that modern coupling is always evolving and that cohabitating doesn’t have the shame it once did.

“At one time marriage may have been seen as the only way for young couples to get the social support and companionship that is important for emotional health,” she said. “It’s not that way anymore. We’re finding that marriage isn’t necessary to reap the benefits of living together, at least when it comes to emotional health.”

What does this all mean? Well, that modern coupling is no less confusing than it has always been. But the fact remains: Moving in with a significant other is a big step that demands thoughtful consideration. You might be happier in the moment, but you also might not realize warning signs before it’s too late.

Oh, and some positive affirmation from recent study. Even if your first relationship doesn’t pan out, emotional happiness can be resurrected from a second go. “The emotional benefits of cohabitation or marriage aren’t limited to first relationships," said the release. “The study found that young adults experienced a drop in emotional distress when they moved from a first relationship into cohabitation or marriage with a second partner."

So, there’s always hope. Do what feels right. Just be sure to keep the car in good condition and check the oil every once in a while.