The nuclear family is a somewhat recent construct that applies mostly to Euro centric cultures. This concept was not even widely possible to achieve in Euro centric cultures because many people, especially in the servant and soldier classes, were not allowed to live with their families, or even to visit them frequently.
With the industrial revolution, the ability to get out of serfdom or servant classes and to be completely independent outside of the job allowed people to marry, have children, maintain their own homes and to make their own decisions about life. With more and more prosperity and stability, the nuclear family peaked as a form of family structure during the 1950s to 1970s.
Then, either the promise of greater education, pay and career success led to physical separation from extended families. Prosperity helped to build larger and more physically separate homes. There was more separation in education, religion and other social activities, creating nuclear families that were isolated, more protective of privacy, more self interested, and with more authority to determine family structure and private behavior.
The law was helped when the populace was sold on the idea of a nuclear family, where clear lines of legal, marital and custody rights were concerned. People could no longer have their children taken away without consideration of their rights.
Now, even parents who have grossly obese, seriously abused, threateningly anti social, tragically spoiled and other problematic children demand their rights to call all of the shots and to keep even the authorities from stepping in. Spousal abuse, criminal activity, complete loss of moral and social compasses and even serial rape and killing can go on with no people being close enough to know that secret lives are being led.
The elderly are warehoused in independent living or assisted living circumstances, with children or extended families who never visit frequently enough to ensure that they are able to care for themselves or are being treated properly. The nuclear family increasingly seems to apply to two generations of parents and their children and to no one else.
The increasingly isolated, self interested and self sufficient nuclear family is becoming responsible for many of the disconnections between, individuals and parents, aunts, uncles, cousins and others with whom they should have closer relationships and bonds.
Families that ignore the “nuclear” form are able to form and to maintain strong bonds as a whole. They have more abilities to share wisdom, history and traditions. Extended families are more able to share values, norms and standards, to share role models, to share resources.
As a result, more families have either always been or are becoming less nuclear and are becoming more accepting of the fact that life and the economy are calling for better forms of family structure, if for the survival and support of each and every member.
Extended families that do not obsess over the isolated and self centered nuclear model are better able to help and to protect each other.