Some people believe that cohabitating before marriage decreases the risk of divorce for a couple. Others believe that cohabitation can doom a marriage before it even begins. The logic behind the theory that cohabitation strengthens future marriages is that when a woman and a man live together before marriage they have an opportunity to live together and test the relationship before making a commitment to marriage. Through these real life experiences cohabitating couples are less likely to be surprised by their partner's habits shortly after marrying and moving in together. When you think about it, the cohabitation theory has merit, after all you wouldn't buy a new car without taking it for a test drive first.

The idea of cohabitation appeals to people's common sense. Many couples who may have at one time gotten married choose to simply live together now in informal cohabitation. Some couples choose cohabitation over marriage for practical reasons, and others just haven't felt the need to make the union official and possibly never will. Many of these couples, approximately 50 percent, get married at some point; however, other couples are perfectly happy living together like a married couple, but without the formalities of a legal marriage.

However, cohabitation does have its pitfalls. Since these unions are informal by nature, the relationships tend to dissolve easier than couples who are married. In fact, some studies show that couples who cohabitate before marriage actually have a higher rate of divorce and long-term separation. One of the main reasons researchers believe these types of relationships fail is because informal cohabitation "undermines the legitimacy of formal marriage." Therefore, cohabitation makes marriage seem like less of a commitment.