Cousin

A cousin is a relative with whom a person shares one or more common ancestors. In the general sense, cousins are two or more generations away from any common ancestor, thus distinguishing a cousin from an ancestor, descendant, sibling, aunt, uncle, niece, or nephew. However, in common parlance, "cousins" typically refers to "first cousins" as the children of one's uncles and aunts.
Systems of "degrees" and "removals" are used in the English-speaking world to describe the exact relationship between two cousins (in the broad sense) and the ancestor they have in common. Various governmental entities have established systems for legal use that can precisely specify kinships with common ancestors existing any number of generations in the past, though common usage often eliminates the degrees and removals and refers to people with common ancestry as simply "distant cousins" or "relatives".
== Basic definitions ==
"First cousin once removed" redirects here. For the documentary film, see First Cousin Once Removed.
The ordinals in the terms "first cousins", "second cousins", "third cousins", refer to the number of generations to one's closest common ancestor.[1] The number of "G" words used to describe this ancestor will determine how close the relationship is. For example, having "great-great-grandparents" in common would be third cousins.
When the cousins are not the same generation, they are described as "removed". In this case, the smaller number of generations to the common ancestor is used to determine the degree, and the difference in generations determines the number of times removed. Note that the ages of the cousins are irrelevant to the definition of the cousin relationship.
=== First cousins[edit] ===
A child ("Sam") of one person ("Laura") and a child ("Ryan") of that one person's sibling ("Robert") are first cousins. First cousins share grandparents ("Joseph" and "Nancy").
Sam and Ryan are first cousins because they are non-siblings who share a pair of grandparents.	
{| 	 	 	 	 	 	 	 	 	Joseph	Joseph	Joseph	Joseph	Joseph	Joseph	 	 	Nancy 	Nancy 	Nancy 	Nancy 	Nancy	Nancy	 	 	 	 	 	
 	 	 	 	 	 	 	 	 	 	Joseph	Joseph	Joseph	Joseph	Joseph	Joseph	 	 	Nancy 	Nancy 	Nancy 	Nancy 	Nancy	Nancy	 	 	 	 	 	
 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	
 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	
Gordon	Gordon	Gordon	Gordon	Gordon	Gordon	 	 	Laura	Laura	Laura 	Laura 	Laura 	Laura 	 	 	Robert	Robert	Robert	Robert	Robert	Robert	 	 	Angie	Angie	Angie	Angie	Angie	Angie
Gordon	Gordon	Gordon	Gordon	Gordon	Gordon	 	 	Laura	Laura	Laura 	Laura 	Laura 	Laura 	 	 	Robert	Robert	Robert	Robert	Robert	Robert	 	 	Angie	Angie	Angie	Angie	Angie	Angie
 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	
 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	
 	 	 	 	Sam 	Sam 	Sam	Sam	Sam 	Sam 	 	 	 	 	 	 	 	 	 	 	Ryan 	Ryan 	Ryan 	Ryan 	Ryan 	Ryan 	 	 	 	
 	 	 	 	Sam 	Sam 	Sam	Sam	Sam 	Sam 	 	 	 	 	 	 	 	 	 	 	Ryan 	Ryan 	Ryan 	Ryan 	Ryan 	Ryan 	 	 	 	
== Additional terms ==
The following is a list of less common cousin terms.
Term 	Definition 	Example 	Chart	 	 	 	 	 	 	 	 	 	 			 	 	 	 	 	 	 	 	 	 	 	 	 	 				
Double cousin	Double cousins arise when two siblings of one family mate with two siblings of another family. The resulting children are related to each other through both of their parents and are thus doubly related. Double first cousins share both sets of grandparents and have twice the degree of consanguinity of ordinary first cousins; genetically, they are as related as half-siblings. In a scenario where two monozygotic (identical) twins mate with another pair of monozygotic twins, the resulting double cousins would test as genetically similar as brothers or sisters. Double second cousins can arise in two ways: from two first-cousin relationships among their parents or from one double-first-cousin relationship between their parents.	David and Irene are double first cousins because each is related through their mother's family and also their father's family, the result of a brother and sister (Ben and Helen) having married another brother and sister (Hugh and Betty). For David and Irene, each has a mother who is an aunt by blood of the other and a father who is an uncle by blood of the other.	 	 	 	 	 	 	 	 	 	 	 			 	 	 	 	 	 	 	 	 	 	 	 	 	 				
Half-cousin 	Half-cousins are the children of two half-siblings, and their respective spouses. 	David and Lilian are half cousins because their fathers (Ben and James) are maternal half-brothers, their grandmother (Agatha) having remarried. 	
{| 	 	 	 	 	Adam 	Adam 	Adam	Adam	Adam	Adam			Agatha	Agatha	Agatha	Agatha	Agatha	Agatha	 	 	Anthony	Anthony	Anthony	Anthony	Anthony	Anthony				
 	 	 	 	 	 	 	 	Adam 	Adam 	Adam	Adam	Adam	Adam			Agatha	Agatha	Agatha	Agatha	Agatha	Agatha	 	 	Anthony	Anthony	Anthony	Anthony	Anthony	Anthony				
 	 	 	 	 	 	 	 	 	 	 	 	 	 			 	 	 	 	 	 	 	 	 	 	 	 	 	 				
 	 	 	 	 	 	 	 	 	 	 	 	 	 			 	 	 	 	 	 	 	 	 	 	 	 	 	 				
Betty 	Betty 	Betty 	Betty	Betty	Betty	 	 	Ben 	Ben 	Ben 	Ben 	Ben 	Ben 			James 	James 	James 	James 	James 	James 	 	 	Janet 	Janet 	Janet 	Janet 	Janet 	Janet 				
Betty 	Betty 	Betty 	Betty	Betty	Betty	 	 	Ben 	Ben 	Ben 	Ben 	Ben 	Ben 			James 	James 	James 	James 	James 	James 	 	 	Janet 	Janet 	Janet 	Janet 	Janet 	Janet 				
 	 	 	 	 	 	 	 	 	 	 	 	 	 			 	 	 	 	 	 	 	 	 	 	 	 	 	 				
 	 	 	 	 	 	 	 	 	 	 	 	 	 			 	 	 	 	 	 	 	 	 	 	 	 	 	 				
 	 	 	 	David	David	David	David	David	David	 	 	 	 			 	 	 	 	Lilian	Lilian	Lilian	Lilian	Lilian 	Lilian 	 	 	 	 				
 	 	 	 	David	David	David	David	David	David	 	 	 	 			 	 	 	 	Lilian	Lilian	Lilian	Lilian	Lilian 	Lilian 	 	 	 	 				
== Relationship charts ==
=== Cousin chart ===
A "cousin chart", or "table of consanguinity", is helpful in identifying the degree of cousin relationship between two people using their most recent common ancestor as the reference point. Cousinship between two people can be specifically described in degrees and removals by determining how close, generationally, the common ancestor is to each person.[2]
If one person's → 	If one person's → 	Parent 	Grandparent 	Great-grandparent 	Great-great-grandparent 	Great-great-great-grandparent 	Great-great-great-great-grandparent
Is the other person's
↓ 	Then they are ↘ 	Parent 	Grandparent 	Great-grandparent 	Great-great-grandparent 	Great-great-great-grandparent 	Great-great-great-great-grandparent
Parent 	Parent 	Siblings 	Parent/Child or Uncle/Aunt/Nibling	Grandparent/Grandchild 	Great grandparent/Great grandchild	Great great grandparent/Great great grandchild	Great great great grandparent/Great great great grandchild
Grandparent 	Grandparent 	Parent/Child or Uncle/Aunt/Nibling 	1st cousins 	1st cousins once removed 	1st cousins twice removed 	1st cousins
3× removed 	1st cousins 4× removed
Great-grandparent 	Great-grandparent 	Great-uncle/Great-aunt/Great-nibling 	1st cousins once removed 	2nd cousins 	2nd cousins once removed 	2nd cousins twice removed 	2nd cousins
3× removed
Great-great-grandparent 	Great-great-grandparent 	Great-great-uncle/Great-great-aunt/Great-great-nibling 	1st cousins twice removed 	2nd cousins once removed 	3rd cousins 	3rd cousins once removed 	3rd cousins twice removed
Great-great-great-grandparent 	Great-great-great-grandparent 	Great-great-great-uncle/Great-great-great-aunt/Great-great-great-nibling 	1st cousins 3× removed 	2nd cousins twice removed	3rd cousins once removed 	4th cousins 	4th cousins once removed
Great-great-great-great-grandparent	Great-great-great-great-grandparent	Great-great-great-great-uncle/Great-great-great-great-aunt/Great-great-great-great-nibling	1st cousins 4× removed 	2nd cousins 3× removed 	3rd cousins twice removed 	4th cousins once removed 	5th cousins
=== Canon law relationship chart ===
Canon Law Relationship Chart. See an example of how to use chart.
Another visual chart used in determining the legal relationship between two people who share a common ancestor is based upon a rhombus shape, usually referred to as a "canon law relationship chart".
The chart is used by placing the "common progenitor" (the most recent person from whom both people (A and B) are descended) in the top space in the diamond-shaped chart, and assigning a direction (arbitrarily, left or right) to each of the two people, A and B. Then follow the line down the outside edge of the chart for each of the two people until their respective relationship to the common ancestor is reached. Upon determining that place along the opposing outside edge for each person, their relationship is then determined by following the lines inward to the point of intersection. The information contained in the common "intersection" defines the relationship.
For a simple example, in the illustration to the right, if two siblings use the chart to determine their relationship, their common parent (either one, if there are two) is placed in the topmost position, and each child is assigned the space below and along the outside of the chart. Then, following the spaces inward, they would intersect in the "brother" diamond.[3] If their children want to determine their relationship, they would follow the path established by their parents but descend an additional step below along the outside of the chart (showing that they are grandchildren of the common progenitor); following their respective lines inward, they would come to rest in the space marked "1st cousin". In cases where one side descends the outside of the diamond further than the other side because of additional generations removed from the common progenitor, following the lines inward shows both the cousin rank (1st cousin, 2nd cousin) plus the number of times (generations) "removed".
In the example provided at the right, generations one (child) through ten (8th great-grandchild) from the common progenitor are provided; however, the format of the chart can easily be expanded to accommodate any number of generations needed to resolve the question of relationship.