Some definitions: George Murdock's definition (over 50 ago) - "The family is a social group characterized by common residence, economic cooperation, and reproduction. It includes adults of both sexes, at least two of whom maintain a socially approved sexual relationship, and one or more children, own or adopted, of the sexually cohabiting adults." Popenoe's definition – “the minimum number constituting a family is one adult and one dependent person, the parents do not have to be of both sexes, and the couple does not have to be married. The functions of the family are procreation and socialization of children, sexual regulation, economic cooperation, and provision of care, affection and companionship.” Nuclear family: wife/mother + husband/father + their children. The one-parent family: one parent (divorced/unmarried parent) + children. Extended familiy : at least three generations: the grandparents, the wife/mother, husband/father, chil