The concept of family has changed in the course of history, as has its value, the sentiment that bonds members of the family and its importance for the individual. At the beginning of the 1960s Aries wrote:

The dynamic nature of the family was thoroughly demonstrated by historical studies, which show that it is not a constant and immutable cell, but it evolves together with the evolution of the entire social structure. Several family models have been dominant in different countries at different times, but the crisis of each model did not involve a crisis in the family per se, only a change brought about by the loss or gain of new characters, functions, and specializations.