Murdock saw this as an extension of the nuclear family.
These extended families contain kin.
3 generation family could have grandparents and aunties and uncles.
First developed in middle class.
It is Nuclear.
Husband and wife look at each other for companionship.
Little contact with kinship.
Roles of husband and wife are similar.
Modified extended family
Kin doesn't seem to play a major role.
Important services are given by the kinship.
Come together for important family events
Communicate through telephone and email.