View Full Version : Strange 23andme Ancestry Composition Results For A French-Canadian

J Man
05-23-2014, 02:55 AM
I share with a fellow on 23andme who is mostly French-Canadian and his Ancestry Composition scores seem a bit strange to me. He has told me that only 2 of his 8 great grandparents were of Irish/British Isles ancestry. 1 was Native Canadian and the other 6 were French. The strange thing is that 4 of my great grandparents were of Irish/British Isles ancestry and I score lower than he does in the British and Irish component on Ancestry Composition. Here are his results for that component compared to mine.

Speculative setting-

Him: 46.6% British and Irish
Me: 43.3% British and Irish

So how can he score more British and Irish than me when I have quite a bit more actual Irish/British Isles ancestry than he does?

Green fairy
05-30-2014, 07:33 PM
Maybe he has ancestry from Brittany, which I think is supposed to be similar to Ireland and other Celtic areas. Unknown adoptions and NPE's also come to mind.

06-02-2014, 01:50 PM
It is not 100% reliable.:(

I am 100% french, and i have, in speculative, 34% British & Irish, and only 16.4% French & German and 29.8% Non specific Northern European.

The "Breton" excuse is not credible.
Many French have at least 20% British& Irish at 23andme!

06-02-2014, 04:30 PM
Many Québécois have Irish ancestry (estimates range as high as 40%), and to a lesser extent English (e.g. Melançon) or Scots (e.g. Moffett, Watson) ancestry.

Of course, we don't know how Aboriginal and how British his Native Canadian ancestor was, either. Many people have First Nations status and are over 80% of Isles descent.

It seems possible that 3/8 are fully Isles (37.5%), and 1/8 is First Nations of which 80% is Isles (10%, total is now 47.5%, pretty much what he has). I suppose this might mean that all of his French grandparents are a little more Irish than average, but his math or paper trail might also be a little wrong.

Possibly not far off though. Canadians of a certain age will remember this:


In effect, this is a problem of assimilation by degrees: the genes stay but the memory of the ancestors is lost. Many English Canadian also have French ancestry they have forgotten about.

11-15-2017, 04:11 PM
Because you have grandparents of a certain ethnicity doesn’t mean the same in genetic admixture. We might not know where they came from before. French Canadians share affinity in admixture with current Irish or British as well as Mediterranean (Iberian Greek Italian) and maybe Scandinavian and some others. Surprising to me was that my Québécoise mother is 40% British with Irish trace regions around 3% but her mother (along with me) is just the opposite, we reported 40% Irish and trace regions of up to 3% British. Siblings can also reflect this with different sometimes reverse admixtures.

11-19-2017, 01:50 AM
not really

11-19-2017, 05:09 AM
It's not an exact science. I have around 62.5% English/Welsh/Irish/Scottish going by paper records and where ancestors immigrated from. But on Ancestry I get 19% Irish, etc. (probably in the ballpark) and only 4% Great Britain, for a total of 23%. That contrasts with 72% at MyHeritage (55.2% English) and 83% British Isles from FTDNA.

I'm sure it could be off in the opposite way for the French Canadian person, although there are other possible explanations.