About Relationships by Marriage
(Affinity - In law and in cultural anthropology, affinity, as
distinguished from consanguinity, is kinship by marriage.
It is the relation which each party to a marriage, the husband
and wife, bears to the kindred of the other.)
A relationship by blood is also referred to as being related
by consanguinity.
A relationship by marriage is sometimes referred to as being
related by affinity.
A husband and wife are related in the first degree by
marriage.
Relationship Terms
Sometimes, especially when working on your family history,
it's handy to know how to describe your family relationships
more exactly. The definitions below should help you out.
Cousin (a.k.a "first cousin")
Your first cousins are the people in your family who have two
of the same grandparents as you. In other words, they are the
children of your aunts and uncles.
Second Cousin
Your second cousins are the people in your family who have the
same great-grandparents as you., but not the same
grandparents.
Third Cousins
Your third cousins have the same great-great-grandparents as
you, but not the same great-grandparents.
Fourth
Cousins
Fourth cousins have the same great-great-great-grandparents as
you, but not the same great-great-grandparents.
Removed
When the word "removed" is used to describe a relationship, it
indicates that the two people are from different generations.
You and your first cousins are in the same generation (two
generations younger than your grandparents), so the word
"removed" is not used to describe your relationship.
The words "once removed" mean that there is a difference of
one generation.
For example, your mother's first cousin is your first cousin,
once removed. This is because your mother's first cousin is
one generation younger than your grandparents and you are two
generations younger than your grandparents. This
one-generation difference equals "once removed."
Twice removed means that there is a two-generation difference.
You are two generations younger than a first cousin of your
grandmother, so you and your grandmother's first cousin are
first cousins, twice removed.
Reference:
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Relationship Chart