Daily AncestorDouble cousin
A double cousin is related through both parents; double first cousins come from two siblings who married two siblings, sharing all four grandparents.
When two brothers marry two sisters, or a brother and sister marry a sister and brother, the children are cousins on both sides of the family. Double first cousins share all four grandparents instead of two.
Double first cousins share roughly as much DNA as half-siblings do, about a quarter, twice the usual share for first cousins. So a DNA match that looks too close for a first cousin may have this explanation.
As seen in a recordFamily history note, 1890s
the children of Jonas and Eli Hartsough, who married the sisters Lucy and Ann Pell, are double cousins
Sources
How to cite this page
Daily Ancestor. "Double cousin." Dictionary of Old Record Words. https://dailyancestor.com/dictionary/relationships/double-cousin. Last checked 2026-10-12.