All AncestryDNA customers to some extent, but especially Jewish and Hispanic customers, have been getting false cousin matches. Matches for Jewish and Hispanic testers seemingly would indicate they’re cousins with everyone else of the same ethnicity.
In today’s announcement, Ancestry.com’s DNA team explains why these false matches can happen. All humans are genetically 99 percent identical, so there are two reasons that two people might have identical DNA:
- IDB: the DNA is Identical By Descent, meaning the two people it belongs to are related
- IDS: the DNA is Identical By State, indicating that the two people it belongs to are simply of the same ethnicity or are both human
Apparently it can be difficult it can be to tease out the DNA segments that are IDB from those that are IDS, but AncestryDNA has developed a new way to analyze results that can tell the difference.
In the coming months, according to the release, “all customers will see increased accuracy of their DNA matches, and significantly fewer ‘false’ matches.” Existing customers will receive an email when their new matches are ready.