A family consists of two or more people related to each other by genetics, adoption, marriage, or in some interpretations, by mutual agreement.

Family is broadly defined as any two people who are related to each other through a genetic connection, adoption, marriage, or by mutual agreement. Similarly, the U.S. Census Bureau defines family as “a group of two people or more (one of whom is the householder) related by birth, marriage, or adoption and residing together.”

The term nuclear family is used to refer to family members who live together and share emotional, economic, and social responsibilities. The nuclear family is often composed of a married couple who are parents to their biological or adopted children; all members live together in one household. This type of nuclear family is increasingly referred to by social scientists as an intact family, signifying that the family has not been through a divorce, separation, or death of a member. This arrangement is commonly called the traditional family.

As found in the study conducted by Brian Powell, a sociologist at Indiana University, and his colleagues, the family is being defined differently. The concept of family is changing. Powell states, “That includes a much greater array of living arrangements. They're including a much broader group of people, broader combination of people as families.” Various factors have affected family structure, for example, divorce and single-parent households. A divorced mother with three children may decide to live with another divorced woman with two children in order to share expenses. Similarly, grandparents may raise their grandchildren when the parents are unable to do so.

Thus, blended or nontraditional families are increasingly the norm. Divorce or parental death typically leaves one parent responsible for raising the children, making the single-parent family. (The terms broken family and broken home are no longer widely used because of their negative connotations.)

Statistics of the family

Many surveys conclude that nearly all people consider a husband, wife, and children as a family, and slightly fewer people consider a husband and wife without children as a family. Usually, fewer than half of all people consider an unmarried man and woman living together as a family. In a similar percentage, less than 40% of surveyed people consider a gay or lesbian couple as a family, but that percentage goes up (to 60% or higher) when children are added. Further, about half of people consider pets as part of a family.

The U.S. Census Bureau, as part of its report “America's Families and Living Arrangements: 2012,” suggested that the definition of family has changed over time, making it unrealistic to focus solely on a single type of family. (The Census report used data from the Annual Social and Economic Supplement [ASEC] to the Current Population Survey [CPS] and the American Community Survey [ACS].)

The Report defines household as “one or more people” , with each household consisting of either a family or a nonfamily. A family household is defined as having “at least two members related by birth, marriage, or adoption, one of whom is the householder.” The definition of nonfamily household is stated as being “either a person living alone or a householder who shares the housing unit only with nonrelatives—for example, boarders or roommates.”

The Census report finds that 66% of households in 2012 were family households, which had decreased from 81% in 1970. Further, from 1970 to 2012, the percentage of families that contained married couples with children under the age of 18 years decreased from 40% to 20%. The Census Bureau added that the average number of people per family declined from 3.1 in 1970 to 2.6 in 2012.

The report also found that partners in married opposite-sex couples were less likely (4%) to be members of different races than partners in unmarried opposite-sex couples (9%) or same-sex couples (12%). For families with only one parent, African American children and Hispanic children were more likely to live in such an arrangement, 55% and 31%, respectively, than were non-Hispanic white children and Asian children, 21% and 13%, respectively.

Head of household

Government agencies and other statistics-gathering organizations use the term head of household to refer to the person who contributes more than half of the necessary support of the family members (other than the spouse); in common usage, the head of household is the person who provides primary financial support for the family.

Stepfamilies and co-parenting

Following the end of one marriage, one or both of the exspouses may enter a new marriage. Through this process of remarriage, stepfamilies are formed. The second spouse becomes a stepparent to the children from the first marriage. In the family formed by the second marriage, the children from each spouse's first marriage become step-siblings. Children born or adopted by the couple of the second marriage are half-siblings to the children from the first marriage, since they share one parent in common.

In some cases, stepparents legally adopt their spouse's children from a previous marriage. The biological father or mother must either be absent with no legal claim to custody or must grant permission for the stepparent to adopt.

In situations in which a single parent lives with someone outside of marriage, that person may be referred to as a co-parent. Co-parent is also the label given to the partner in a homosexual relationship who shares the household and parenting responsibilities with a child's legal adoptive or biological parent.


The familial care or guardianship of someone.
U.S. Census Bureau—
A principal agency of the federal government that is responsible for producing data about Americans and the U.S. economy.

Family home and extended family

The home that was owned by the family prior to a divorce or separation is referred to as the family home in many state laws. In court settlements of divorce and child custody issues, the sale of the family home may be prohibited as long as the minor children are still living there with the custodial parent. The sale of the home may be permitted (or required to pay the noncustodial parent his or her share of its value) if the custodial parent moves or remarries or when the children leave home to establish their own residences.

The term extended family traditionally meant the biological relatives of a nuclear family, that is, the parents, sisters, and brothers of both members of a married couple. It was sometimes used to refer to the people living in the household beyond the parents and children. As family relationships and configurations have become more complex due to divorce and remarriage, extended family has come to refer to all the biological, adoptive, step-, and half-relatives.

Factors that make for a happy, healthy family

Although many varieties of the family exist in the twenty-first century, there are ways to know if a particular family is happy and healthy. The AAP's report “Caring for Your School-Age Child: Ages 5 to 12” discusses those qualities that need to be present to evaluate how well a family is functioning. These qualities include love, mutual respect, support, open communication, and a sense of belonging.

Based on this AAP report, the website lists questions that help reveal a welladjusted family.

See also Adoption ; Divorce ; Marriage counseling .



McCarthy, Jane Ribbens, and Rosalind Edwards. Key Concepts in Family Studies. London: SAGE, 2011.

Redmount, Esther, ed. The Economics of the Family: How the Household Affects Markets and Economic Growth. Santa Barbara, CA: Praeger, 2015.

Rimmerman, Arie. Family Policy and Disability. New York: Cambridge University Press, 2015.


Carr, Deborah, et. al. “Happy Marriage, Happy Life? Marital Quality and Subjective Well-being in Later Life.” Journal of Marriage and Family 76, no. 5 (October 2014): 930–48.


American Academy of Pediatrics. “America's Normal Functioning Family.” (accessed August 5, 2015).

American Academy of Pediatrics. “The ‘Perfect’ Family.” (accessed August 5, 2015).

Schulten, Katherine. “How Do You Define ‘Family’.” New York Times. (accessed August 5, 2015).


American Association for Marriage and Family Therapy, 112 S. Alfred St., Alexandria, VA, 22314-3061, (703) 838-9808, Fax: (703) 838-9805, .

Family Service Association, 702 Pedro Ave., San Antonio, TX, 78212, (210) 299-2400, Fax: (210) 299-4498,, .

National Council on Family Relations, 1201 W. River Pky., Ste. 200, Minneapolis, MN, 55454-1115, (763) 7819331, Fax: (763) 781-9348, (888) 781-9348,

Step Family Foundation, 310 85th St., Ste. 1B, New York, NY, 10024, (212) 877-3244,, .