In virtually all cultures, the family is considered the basic societal unit. Because the U.S. Census Bureau provides the most comprehensive statistics available on families in America, this book uses its terms and definitions as they concern the American family. The Census Bureau conducts a nationwide population census every ten years. In addition, the Bureau gathers economic information and surveys state and local governments every five years. The Bureau completes more than a hundred annual surveys and publishes a wide variety of special reports each year.
The Census Bureau defines a family as two or more people related by blood, marriage, or adoption. To understand this definition of the family, one must first understand the terminology used by the Census Bureau to describe the wide variety of living arrangements in the United States. In gathering its statistics, the Census Bureau starts with the American "household"—a single housing unit occupied by a person or group of people. Group quarters, such as correctional institutions and nursing homes, are not counted as households.
The "householder" is the person in whose name the housing unit is owned, being purchased, or rented. A "family household" consists of a householder and one or more people who are related to the householder by blood, marriage, or adoption. A "nonfamily household" consists of a person living alone or living only with nonrelatives, such as boarders or roommates.
Family households are further divided into the traditional family maintained by a "married couple" and "other families" maintained by a male or female householder with no spouse present. These might include a single parent living with a child or children, siblings sharing a home, and any combination of relatives other than the householder's spouse.