Nuclear Family: Family group consisting of parents and their children (one or more)

It is made up of a husband, a wife, and their children. Not everyone agrees on what a nuclear family is. Some people say that a nuclear family does not include stepchildren or adopted children. Others say that a nuclear family may include stepchildren or adopted children. A nuclear family is a part of an extended family.

The term nuclear family was first used in 1947. However, people have lived in nuclear families for thousands of years. In 2005, archaeologists discovered four 4,600-year-old graves in Germany. Several adults and children who were related were buried in these graves. Researchers think that this proves that people lived in nuclear families a long time ago.

During and before the medieval period in Europe, large family groups, such as clans, were most common. By the late medieval period, the nuclear family had become most common.