How many Grandparents

[cmbearly]

If people matched dna as 2nd or 3rd cousins, what level of grandparents would they share?

[cbeck]

Third Great I think

[MMaddi]

If people matched dna as 2nd or 3rd cousins, what level of grandparents would they share?

Of course, estimates of a cousin relationship based on shared DNA are merely that - estimates. You would have to confirm the relationship in the paper trail to be sure of the exact relationship. For instance, an estimated relationship of 2nd-3rd cousins would include 2nd cousins, once removed or even 1st cousins, twice removed. Those two additional relationships could have similar amounts of shared DNA as are in the sharing range between 2nd and 3rd cousins.

But, to answer your question, 2nd cousins share a set of great-grandparents and 3rd cousins share a set of gg-grandparents. The rule of thumb is to take the number g's before grandparent and add 1. That will give you the degree of cousin relationship. So, if two people share common grandparents, there's no g before grandparent, so add 1 to zero and that tells you they're 1st cousins. Or two people who share a set of gggg-grandparents are 5th cousins.

Or just print out the chart at http://freepages.genealogy.rootsweb....nthro/grc.html. You'll see the cousin relationships down the diagonal marked in bold. It also shows you cousins who are different generations back to the common ancestors, with the degree of removal, as in 1st cousin, twice removed or 3rd cousin, once removed.

[Serket]

I have two matches listed in the range of 2nd to 3rd cousin. For one of them our common ancestors were through my 3rd great-grandparents and for the other one it was through our mutual 2nd great grandparents.

[JerryS.]

3rd cousins would share the same great grand parent.