"what we know to be true" is NOT what is covered in these DNA tests.
I'm sorry that I started this thread because it seems to have caused a lot of confusion and, yes, maybe even friction on the Board.
DNA tests tell you where your GENES came from hundreds, even thousands of years ago. I doubt very, very much that 99% of us know this information with certainty.
Bear, twins who are not identical and siblings from same parents CAN have different DNA because their parents have differing DNA....they will get some from mom, some from dad, etc. etc. I have one daughter who is more Irish/Scandinavian/western Europe and the other is more Scot/Scandinavian/western Europe. Yet you could also say we are all Viking as that area is the common genetic pool between us. (Perhaps explains the red hair, pale skin, strong personalities, and temper in the family that we "know"!)
The results of these DNA tests come back with REGIONAL associations, not necessarily country associations. E.g. Great Britain instead of "England"; Western Europe instead "France" or "Austria"; Mediterranean instead of "Sicily" or "Italy", etc., etc.
You may know (or believe) you had recent (as in the past 300 years) ancestors who "came from Italy," but may discover those ancestors' ancestors came from Northern Africa or Eastern Asia, intermarrying (and, yes, being sperm donors) along the way. There is just no way any of us can really know from whence we came 800, 1000, 1500+ years ago without DNA studies. Even American Indian and Australian Aboriginal populations "came" from somewhere else. Since the beginning of humans, people were incredibly mobile and they interacted, mixed it up, with other populations creating the glorious amalgam of ancestries we know today....through DNA studies.
I find it fascinating, the story of us. But I'm truly sorry I've yanked some chains here. If it doesn't interest you, or you fear "being tracked", by all means, don't bother with it!
Jan in VA