First Cousin 2x Removed, Second Cousin - What does it mean?

One item that can be tricky in family tree research is understanding relationships between individuals. Understanding parents, grandparents and children is relatively straight forward. Understanding the relationships between cousins is what tends to be the most confusing. The term second cousin is often used incorrectly.

Some basic information on understanding the relationships between cousins, that I am using from Wikipedia and Genealogy.com:

The degree (first, second, third cousin, etc.) indicates one less than the minimum number of generations between both cousins and the nearest common ancestor.

• First Cousin: a person with whom one shares a grandparent (but not a parent). These individuals are typically the children of your aunts and uncles.
• Second Cousin: someone with whom one shares a great-grandparent (but not a grandparent or a parent)
• Third Cousin: someone with whom one shares a great-great-grandparent (but not a great-grandparent or grandparent or parent)
• Fourth Cousin: someone with whom one shares a great-great-great-grandparent (but not a great-great-grandparent, great-grandparent or grandparent or parent)

The removal (once removed, twice removed, etc.) indicates the number of generations, if any, separating the two cousins from each other.

•  The child of one's first cousin is one's first cousin once removed because the one generation separation represents one removal.
• Oneself and the child are still considered first cousins, as one's grandparent (this child's great-grandparent), as the most recent common ancestor, represents one degree.
• Removal can also be listed with an x. Example 2x indicates two times removed.

A cousin chart is also a great visual to understand the degree and removal relationships between individuals.

A double cousin is when two siblings of one family reproduce with two siblings of another family. Double cousins share both sets of grandparents in common. Genetically, they can be as closely related as half-siblings.

Information Obtained From:

1. http://en.wikipedia.org/wiki/Cousin_Removal, February 14, 2011
2. http://www.genealogy.com/16_cousn.html, February 14, 2011