[ ]Mapping the Familyrabbis were aware of the complex relationships that could exist within a
family. Individuals might simultaneously have multiple roles, and these
roles complicate the shifting of roles required in levirate.
Descent and Kinship
Descent determines an individual’s rank or social position; it often de-
termines inheritance rights. There are several approaches to tracing de-
scent. A unilineal descent system is one in which an individual traces
his or her descent through only one parent, treating only individuals
related to t hat pa rent as k i n, whereas a cog nat ic descent system is one i n
which descent is traced through both parents.
A unilineal descent system may be patrilineal or matrilineal. If the
system is patrilineal, descent is traced through the father; all members
of the lineage share a common male ancestor (see figure ). Ego and his
siblings, both male and female, belong to the lineage of their father.
They are of the same lineage as their father’s brothers and sisters, but
the children of their father’s sisters are not part of the lineage; rather,
those children belong to the lineage of their fathers. Ego’s mother’s fam-
ily belongs to a different lineage altogether, so that Ego is not reckoned
part of the lineage that includes his mother’s father, siblings, or their
Figure 2. Patrilineal descent system (shaded figures are members
of Ego’s patrilineage)