how they run the tests. You're also GROSSLY oversimplifying how DNA works. Do you technically get 50% from each parent? I guess, but in real life there are differences between siblings. The ancestryDNA I'm reasonably sure is looking at your "traits" for lack of a better technical term or lack of my understanding it any better. At least that's what I've been told by people on this board and by Ancestry.com at one time.