In the years between 1960 or so and the end of 20th century, however, their were many new changes in the structure of the family around the globe.
From the 1960s to the 1990s, the divorce rate in the Western world greatly increased and the birthrate fell by half.
The member of single-parent families rose, and the member of couples living together without marriage went up even more.
At the end of the 20th and beginning of the 21st centuries young adults of some economic classes started staying with their parents longer, marrying later, and having kids at and older age, if at all.