Pew Research Center reports that an overwhelming majority (78%) of young adults under age 30 believe it is wholly acceptable for unmarried couples to live together with no intentions of marrying. Many people (48%) believe living together leads to more successful marriages, and a stronger majority (63%) of young adults think this is true.

Of course, this could not be more wrong.

Top academic research over the last several decades consistently shows the precise opposite. Cohabiting prior to marriage actually leads to much higher risk of divorce and less healthy relationships. This is even more disturbing when we consider that over 75% of all marriages entered today are preceded by some form of premarital cohabitation.

Some of the most powerful recent research on the negative outcomes of cohabitation comes from Stanford University. All things being equal, the Stanford scholars conclude “the couples who had cohabited before marriage had a substantially higher rate of divorce than couples who had never cohabited” (emphasis added) and “the marriage stability disadvantage of premarital cohabitation emerges most strongly after 5 years of marital duration and remained roughly constant over time and over marriage cohorts.”

No, cohabitation offers no encouraging prospects of contributing to lasting successful marriage. Just the opposite.

The Stanford research demonstrates the specific risks of marital dissolution for various cohabiting situations compared to non-cohabitors were as follows:

  • Odds of marital dissolution in any year of marriage (beyond first 12 months) for woman who cohabited with husband prior to marriage: 1.19 times higher.
  • Odds of marital dissolution for woman who cohabited with one partner other than husband prior to marriage: 3.25 times higher.
  • Odds of marital dissolution for woman who cohabited with two or more partners other than husband prior to marriage: 66 times higher.

These findings of negative relational consequences from living together outside of marriage have become so consistent through the academic literature, that the fact has been given a name by those who study it: the cohabitation effect.

When sociologists of marriage and the family use that term at professional conferences and in faculty meeting rooms, they all know what it means and there is very little debate about the fact. Most of the debate among scholars centers, not on whether the cohabitation effect is true, but why it is true.

Is Cohabitation Harmful Merely Because It is Stigmatized?

The Stanford scholars wondered if the serious negative relational aspects of cohabitation over the decades might have something to do with the fact that living together has been associated with harmful social stigma because some see it as sinful.

Might greater social acceptance significantly dampen the cohabitation effect? The Stanford scholars call this “the normalization hypothesis”: As cohabitation becomes the “norm” for more couples, maybe it becomes less harmful?

This is a theory, they conclude incidentally, “we find little support for.”

This Stanford researchers looked at 6 different waves of the respected National Surveys of Family Growth (NSFG) over several decades and determined “the association between marital dissolution and premarital cohabitation has not changed over time or across marriage cohorts.”

The various NSFG waves across multiple decades to the present “consistently found that premarital cohabitation was associated with a greater hazard of marital dissolution” and the most recent wave “found that premarital cohabitation was a significant predictor of marital dissolution for couples who had been married for 10, 15, and 20 years” but not for those married 5 years or less.

This fact establishes the damaging impact of cohabitation appears to manifest throughout the growing years of marriage, serving as a looming relational Sword of Damocles.

The Stanford researchers found no support for the idea that as cohabitation became more socially accepted, it loses its negative consequences. As we just observed, these scholars found the relationship between cohabitation and later divorce “has not changed across time or across marriage cohorts.”

But these scholars are not alone in this finding.

A previous study conducted at Penn State and published in 2003 compared cohabitors and marrieds in very distinct generations finding “there was little evidence that the negative consequences of cohabitation dissipated over time as cohabitation became more prevalent.” They explain, “cohabitors in both cohorts continued to exhibit poorer marital quality and greater marital instability.”

Regardless of how many people assume living together before marriage can serve as an effective relational testing ground leading the stronger marriages, the best social science research consistently tells us this is not true. One of the most damaging things couples freely do to harm their future marital prospects is to move in together before walking down the aisle. And doing so continues to be just has harmful to marriage is it ever has been.

Young couples and their families would be wise to remember this fact.

Resources and Related Articles

Living Together Before Marriage: How to Have a Conversation with Someone Making the Wrong Choice

Does Living Together Hurt of Help?

Cohabitation: Why Traditional Marriage Matters

Living Together But Not Married? Consider the Power of the Vow