Simple Unilineal Structure

Patrilineal descent affiliates an individual with a group of kin who are related to him through his father alone.Thus in patrilineal systems, the children in each generation belong to the descent group of their father their father in turn belongs to the descent group of his father and so on.Although a man's sons and daughters are all members of the same descent group,affiliation to that group is transmitted only by the sons.The term agnatic is often used for referring to transmission of descent in the male line.

Matrilineal descent affiliates an individual with a group of kin who are related to her through her mother alone.Thus in matrilineal systems the children in each generation belong to the descent group of her mother;their mother in turn belongs to the descent group of her mother and so on.Although mother's sons and daughters are all members of the same descent group affiliation to that group is transmitted only by the daughters.The term uterine is often used for referring to transmissions of descent in the female line.

Both patrilineal and matrilineal rules of descent are unilineal rules because an individual reckons descent through linkages with members of exclusively one sex only- either male only or female only.In a society with unilineal descent the people refer themselves as belonging to a particular unilineal descent group because they believe all the members of that particular group to be related by virtue of common descent.