When a genealogical DNA site uses your DNA to project a relationship based upon shared DNA, do you look to see how much DNA you actually share? If a “known cousin” does a test, do you see if the amount of DNA you share is typical for the relationship? It’s a good idea to do so for at least two reasons:
- It familiarizes you with the elements of the DNA cousin prediction process
- It allows you to see if the amount of shared DNA is typical (or not) for the biological relationship you think you have with that relative.
The data summaries from Blaine Bettinger’s “Shared CM Project” indicate the typical ranges of shared DNA for specific relationships based upon submissions to his study. We also analyzed some of my closest matches and compared them with the typical ranges from Bettinger’s study on my Rootdig blog. Fortunately my shared DNA with my closest relatives was typical.