The rest of the time, they are the biological offspring of the couple. In fact, about 40 percent of children born to supposedly 'single' mothers today are actually born into two-parent, cohabiting households. And about two-fifths of all children in America spend some time living with their mother and a cohabiting partner. Research confirms the common impression that there are differences between people who cohabit and those who don't, according to Smock. On average, their socioeconomic status tends to be slightly lower, they tend to be slightly less religious and they tend to be slightly more liberal and supportive of egalitarian, non-traditional gender and family roles.
Cohabitation is now common among all groups of people.
While common sense suggests that premarital cohabitation should offer couples an opportunity to learn about each other, increasing their chances for a successful marriage, the evidence suggests just the opposite, Smock finds. In recent years, many patterns of cohabitation seem to be changing, Smock says. Women in the 90s were more likely than women in the 80s to cohabit rather than marry in response to pregnancy. Together, these trends suggests that cohabitation is becoming more a substitute for marriage, rather than a form of engagement that culminates in marriage. As major changes in the American family continue, Smock believes that it is time to bring the complexity of contemporary living arrangements into the public discourse.