Dick Eastman disturbed a hornet's nest with a blog posting "There is no such thing as a half-cousin"
One of my pet peeves is a term that I see online over and over: someone claiming to be a "half first cousin" or a "half second cousin once removed" or something similar. Sorry folks, but there is no such thing as a "half first cousin."He is careful to restrict his argument to US usage only, citing Black's Law Dictionary which defines first cousins as: "The children of one's aunt or uncle."
Dick goes on to point out that "it says "aunt OR uncle," not both. All that is required is to share one aunt or one uncle, not both."
With this definition you could be first cousin to someone with whom you have no bloodline relationship. Your mother's sister marries a man who becomes your uncle. She dies and he remarries and has children. They are your first cousins!
Dick's article has drawn more than 50 comments.
One references an article by Elizabeth Shown Mills which analyzes kinship and includes a glossary of terms where one finds: "Half Relationships: Those that stem from a half-sibling kinship. For every lateral or collateral relationship a "half" equivalent exists. For example:
Half-aunt/uncle: The half-sibling of one's parent.
Half-first cousin: The child of a half-aunt or half-uncle."
Another references the Oxford English Dictionary: "Half-cousin is defined as "The child of one's father's or mother's cousin; a second cousin. Sometimes applied to the child of one's own cousin, or to the cousin of one's father or mother."
This definition implies a half-cousin is the same as a second-cousin.
Respected genetic genealogist Ann Turner comments that "The distinction between full and half cousin is certainly meaningful in the genetic context. Now that autosomal DNA testing is available, it's useful to know that full first cousins share 12.5% of their DNA, while half first cousins share 6.25%."
Obviously there's confusion. Best to check on the convention being used if unsure.
Like many commenters I'll continue to use half-first cousin for a relative who shares one grandparent.