In recent decades, writes Wendy Manning, cohabitation has become a central part of the family landscape in the United States—so much so that by age 12, 40 percent of American children will have spent at least part of their lives in a cohabiting household. Although many children are born to cohabiting parents, and cohabiting families come in other forms as well, the most common cohabiting arrangement is a biological mother and a male partner.
Cohabitation, Manning notes, is associated with several factors that have the potential to reduce children’s wellbeing. Cohabiting families are more likely than married families to be poor, and poverty harms children in many ways. Cohabiting parents also tend to have less formal education—a key indicator of both economic and social resources—than married parents do. And cohabiting parent families don’t have the same legal protections that married parent families have.
Most importantly, cohabitation is often a marker of family instability, and family instability is strongly associated with poorer outcomes for children. Children born to cohabiting parents see their parents break up more often than do children born to married parents. In this way, being born into a cohabiting family sets the stage for later instability, and children who are born to cohabiting parents appear to experience enduring deficits of psychosocial wellbeing. On the other hand, stable cohabiting families with two biological parents seem to offer many of the same health, cognitive, and behavioral benefits that stable married biological parent families provide.
Turning to stepfamilies, cohabitation’s effects are tied to a child’s age. Among young children, living in a cohabiting stepfamily rather than a married stepfamily is associated with more negative indicators of child wellbeing, but this is not so among adolescents. Thus the link between parental cohabitation and child wellbeing depends on both the type of cohabiting parent family and the age of the child.