nuclear family

A nuclear family, elementary family, atomic family, cereal packet family or conjugal family is a family group consisting of parents and their children (one or more), typically living in one home residence. It is in contrast to a single-parent family, a larger extended family, or a family with more than two parents. Nuclear families typically center on a married couple which may have any number of children. There are differences in definition among observers. Some definitions allow only biological children who are full-blood siblings and consider adopted or half- and step-siblings a part of the immediate family, but others allow for a step-parent and any mix of dependent children, including stepchildren and adopted children. Some sociologists and anthropologists consider the extended family structure to be the most common family structure in most cultures and at most times, rather than the nuclear family. The term nuclear family was popularized in the 20th century. Since that time, the number of North American nuclear families is gradually decreasing, while the number of alternative family formations has increased. Etymology The term nuclear family first appeared in the early 20th century. Merriam-Webster dates the term back to 1924, while the Oxford English Dictionary has a reference to the term from 1925; thus it is relatively new. The phrase is taken from the general use of the noun nucleus, itself originating in the Latin , meaning "nut", i.e. the core of something. In its most common usage, the term nuclear family refers to a household consisting of a father, a mother, and their children, all in one household dwelling. George Murdock, an observer of families, offered an early description: