The family is the oldest of human institutions. In the United States, family has been defined as a husband, wife and their unmarried children living together. This is the family type referred to as a nuclear family by sociologists. People in the United States see the nuclear family as the preferred form of family arrangement. By contrast, an extended family is a family in which blood relatives, in addition to parents and children, live in the same home.
Societies vary in the way that power is distributed within the family.
If a society expects males to dominate in all family decision making, it is termed a patriarchy . In contrast, in a matriarchy , women have greater authority than men do. The third type of authority pattern, the egalitarian family , is one in which spouses are regarded as equals and share power and decision making responsibilities. This does not mean, however, that each decision is shared in such families. Mothers may hold authority in some spheres and fathers in others.