Through the presentation of families other than the nuclear family, which is assumed to be the norm, literature shows how nontraditional families fulfill, or fail to fulfill, the functions of nurturing, teaching, protecting, and providing, which are the family’s main purposes for existing. Nontraditional families include single-parent households, stepfamilies, adoptive families, grandparents or other nonparent relatives raising children, and homosexual couples with or without children. Large extended families living together might also be considered to be nontraditional (although this kind of family is traditional) because it is relatively rare in North America in the late twentieth century.
The traditional nuclear family is actually a relatively new family unit. In many cultures and throughout much of human history, families included many more people: grandparents, aunts, uncles, cousins, and various in-laws. Families have also historically included fewer members than the nuclear family does. Death from childbirth, wars, diseases, and desertion have long removed members of families. Literature shows that stepparents, stepsiblings, half-siblings, and in-laws are not modern inventions. The ways in which these variant families are accepted or not accepted by their communities can inform the reader about the culture and time period being discussed and about the culture and time period that produced the story.
Governments and religions have refused to acknowledge certain groups as families. Mothers and their out-of-wedlock children have often been refused the status granted other families. Stepchildren and stepparents have often had trouble coming to an understanding with one another. Gay and lesbian couples have almost always been denied the right to live together and the right to raise children.