Defining Cousins

Culturally, a lot of people use the term “cousin” to describe various relatives without understanding what it actually means.  Legally and medically, the types of cousins needs to be determined precisely, especially concerning inheritance, and genetic conditions. 

In the lineal kinship system, used in the English-speaking world, a cousin is a type of familial relationship in which two relatives are two or more familial generations away from their most recent common ancestor.  Arabs, the Indian subcontinent, and certain other cultures, do not necessarily subscribe to these definitions of types of cousins.  People are considered related with a type of cousin relationship if they share a common ancestor, and are separated from their most recent common ancestor, by two or more generations.  This means neither person is an ancestor of the other; they do not share a parent, so are not siblings; and neither is a sibling of the other’s parent, meaning none is an uncle or aunt to a nephew or niece. 

The cousin relationship is further detailed by the concepts of degree and removal.  Degrees and removals are used to describe the relationship between cousins more precisely.  Degree measures the separation, in generations, from the most recent common ancestor to one of the cousins, whichever is closest, while removal measures the difference in generations between the cousins themselves.  The degree is the number of generations subsequent to the common ancestor before a parent of one of the cousins is found.  This means the degree is the separation of the cousin from the common ancestor less one.  Also, if the cousins are not separated from the common ancestor by the same number of generations, the cousin with the smallest separation is used to determine the degree.  The removal is the difference between the number of generations from each cousin to the common ancestor.  Two people can be removed but be around the same age due to differences in birth dates of parents, children, and other relevant ancestors.