Parsons functional fit theory
The function or type of the family will depend on the structure
Nuclear family = modern industrial society
Extended family = traditional pre-industrial society
There are two essential needs in modern society:
Geographical mobile workforce = as industries moves, people move and so the nuclear family is small and impact, it is easier to form nuclear families
Social mobile workforce = the status is now achieved and so the children can achieve a better status than their parents which causes conflict which can result on the formation of nuclear families