In ancient times, there was an option for a man who desired a regular sex partner but did not wish to marry her. He could take a low-status woman as a concubine. He could enjoy her company as long as it pleased him, and he could dismiss her at any time. The man made no promises and signed no contract; consequently, the concubine had few legal protections. Any children that she bore would have an inferior legal status.
The early Church fought long and hard against concubinage. It insisted that such a sexual relationship, without the permanent and total commitment expressed in marriage vows, was immoral and unjust. Over the course of a thousand years, concubinage retreated into the shadows of social disapproval.
In the past 40 years, it seems, concubinage has come to light again under a different name. Like ancient concubinage, contemporary cohabitation is a deliberately ambiguous relationship. The partners make no promises and have no legal obligations to one another. The arrangement has no specified duration and can be terminated at a moment's notice. Those who cohabit tend to be of lower social status. Their children, on average, do not fare as well as children born to married couples.
Defenders of cohabitation portray it as just a more flexible form of marriage. The love is the same as in marriage, they say; all that is missing is "a piece of paper," the marriage certificate. Some see cohabitation as a "trial marriage." They assume that living together will confirm a couple's compatibility and reduce the odds that a subsequent marriage might end in divorce.
Social science does not support any of these assertions. By every measure, cohabitation is a very different relationship from marriage. Marriages are formed by a series of decisive, publicly announced events: A proposal is made, it is accepted, an engagement is announced, friends and family gather for a wedding, vows and rings are exchanged, and two formerly single persons are declared to be married. By contrast, many couples quietly drift into cohabitation. They gradually spend more time together, one moves his or her possessions piece by piece into the other's residence, one allows his or her lease to expire, and eventually they realize that they are living together full-time.
The two relationships differ dramatically in durability. The average marriage lasts several decades; the average cohabitation, only 15 months. Because their time horizons are longer, married people are much more likely to invest in one another. Husbands and wives almost always pool their assets. They have a single household budget that does not separate "his" and "her" money. They take responsibility for each other's debts and inherit each other's estates.
