Don’t be Fooled by Ethnicity

Many people who see that their ethnicity estimate from a DNA test is way off, think that they cannot trust the other findings from that testing company. That is a false assumption.

When you are shown people who share DNA with you, aka DNA matches, they really are your relatives, although some can be quite distant. What the relationship actually is may not be predicted very accurately, as many relationships share similar amounts of DNA. Examples of that are a grandparent and an aunt or a 2nd cousin and a first cousin once removed. Thus you are usually shown a range of possible relationships. Figuring it out from shared matches and trees can be lots of fun!

Recently “Gail,” a DNA match to my South African 3rd cousin Sharon, contacted me. The only common ethnicity that was shown for them at their testing company was Ashkenazi Jewish. Thus she was assuming that their common ancestors were Jewish.

However the problem is that Gail inherited her 2.7% Jewish from her mother who does not match Sharon. Gail has no Jewish on her father’s side that she knows of. My cousin’s 28% Jewish is from her maternal grandmother. That is the line where Sharon matches me (click here for that story). Gail does not match any other of my many many tested family members on that line.

One of the issues that people of Northern European descent have is that our ancestors intermingled quite a bit. This means that your Scandinavian could be my English and I suspect that is the case here. Another problem is that unlike relative matching, predicting your biological ancestry from your DNA is far from an accurate science (click here for my most recent article of many on that subject)

More accurate than ethnicity are the shared relatives. When looking at the matches Sharon and Gail share, I found a set of common ancestors among them that are from a non Jewish South African line.

Example of a DNA relative in the shared list of matches at MyHeritage on the match’s page with the triangulation symbol (my red arrow)

I also found a relative who shares the same large segment of DNA that triangulates with Gail and Sharon. When you share a large segment match among 3 people, the expectation is that it is from a common ancestor.

Interestingly this match shares Scandinavian with Gail as shown below.

Several testing companies like 23andme and Ancestry now show ethnicity broken down by chromosome. MyHeritage does not do this yet. When I looked at the ethnicity of the larger segment Sharon and Gail share at GEDmatch, it was clearly North European. The smaller segment was less clear and could be Jewish or false.

The lesson here is to not jump to conclusions based on shared bio-ancestry. Look at the other evidence such as shared relatives and the actual segment(s).

12 thoughts on “Don’t be Fooled by Ethnicity

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  1. Thanks for this information, I’m new to genealogy, so I didn’t even think about how intricate DNA could be in linking ancestors and people to each other. I’ll definitely have to remember this so I can be careful in the future when I start doing my own work.

  2. Kitty, This is not in relationship to the ethnicity article. I am struggling with Ancestry to get answers as to why some of my shared DNA matches are now missing. On one day they were there and the next day they were gone.
    In particular I have a distant cousin with whom I share 13 cm and I had
    4 shared matches, one of which was a rather close cousin of mine. They next day 3 of the shared matches were gone and it was the same for some other distant cousins via the same line. The receptionist at corporate gave me an email address for customer solutions and told me to email them about the problem. I have had four emails with them, that range from I am too stupid to understand how DNA works to the last one that suggests that Ancestry is using a new criteria for shared DNA matches other than the 20cm break off. The last employee wanted to talk about generational distance and how dna matching with distant cousins is not relevant. Do you have any inroads with Ancestry? My email address is provided below. Sorry to be venting. Bill Dick

    • Bill,
      Users can choose to not be shown to their matches from their DNA settings page. I suspect that the rather close cousin had made an unwelcome discovery and chose to make themselves and their family no longer visible. Best to give them time to process that.

      • Kitty, Thanks, but that is not the case. I am in regular communication with the rather close cousin and neither he nor his wife have done such a thing. There are two more cousins who also disappeared from the same set of four shared matches. All three of these dna cousins show up as dna cousins of mine, just no longer shared matches with the noted distant cousin.

  3. Oh, OK then likely Ancestry’s latest algorithm has decided that the shared DNA with your distant cousin is common in his ethnic population and removed it (see you are talking about ethnicity after all!)

    Best if you all upload to so you can examine the unfiltered shared DNA. Or upload to Family tree DNA (cant compare 2 cousins to each other only the kits you control) or MyHeritage (no X and again only compares to kits you control but many good tools)

  4. Kitty,

    Thanks for the advice. Sadly he died two years ago and his daughter does not have his password. I am hoping to help her figure out a way for me to be a collaborator on the account. Would love for her to take his DNA to GEDmatch, but we have to get her into Ancestry first. Account is unpaid for some time as well. Thanks again, Bill

  5. Kitty, I’ve just recently started building out trees for who might be my grandmother’s parents, as a result of my ethnicity results. I had already built out the tree for her family, going back to my 5th ggf, in Denmark, based on the records I found, before I did DNA. When I did DNA, it showed NO Danish ethnicity, but Norwegian, but in various classes everyone said the same thing; it had to do with the reference groups. That made sense.

    Then a year or so ago, I started separating out the different lines through DNA, in order to determine HOW my matches were connected to me. And I found a group that does NOT match any of my ancestors. And when looking at one comparison (for a different line), I realized SHE had Danish genealogy, but I still didn’t.

    I reached out to five 2-3 cousins (suspect they are half cousins), and one person replied, giving me names of her Norwegian side. I’m now working on building that tree, since, of course, NONE of them have any decent trees. I found the location of the ancestor who first came to America, and then today I went back into my ethnicity results and found that that location is the same as where this person came from, making me feel I’m on the right track.

    I know there’s controversy around these ethnicity estimates. Listening to these comments about the accuracy of ethnicity estimates, I don’t know if I’m heading down an unnecessary path of building out all of these trees, trying to find who these 2-3 cousins have in common. I suppose if I could find ANY connection to this grandmother, I would think I’ve gone down a rabbit hole I don’t need to. But even on ThruLines, there is NO connection with anyone on that line.
    So, I guess my question is; should I continue to build out these trees??

  6. Margie –
    You are on the right track. Not so much because of the ethnicity results, although they are a clue, but more because of the lack of connection to your grandmother’s lines as you have them. So no connections on either side? Then perhaps she was an informal adoption (neighbors died and their child taken in by friends)… Also upload your DNA to MyHeritage and FamilyTreeDNA, both of which have many Norwegians not on Ancestry. Remember also that Norway and Denmark were one country before the Napoleonic Wars. Still Ancestry is pretty good these days at listing ancestral communities.
    Finally read this for an example of dealing with the type of mystery you are pursuing.

  7. Thank you, Kitty!
    Yes, my plan is to create a fake child and then switch the tree to connect to my DNA, to see what comes up on ThruLines. I’m trying to build out this tree, first, though.
    THEN I will also go deeper into MyHeritage and FTDNA. I also want to play around with WATO, but again, I first want to finish the tree.


  8. Kitty,
    I want to get clear how I would switch my DNA to my test tree to find my grandmother’s parents. I’ve build out a tree, and have been able to connect to two of my matches.
    Do I then create a fake name – ANY name? – for my grandmother, put her as the child of a hypothesized parent, and attach my DNA to it?
    I haven’t done WATO yet, but now that I have two matches, should I do that first?
    Thanks so much!

  9. Margie –
    Do both once you have a theory. But if you are using your DNA make a fake self connected to a fake parent connected to a fake grandma in the test tree to keep with the expected generational differences.
    Do you have other descendants of your grandma tested? If not, get some to help with this project and have them share their DNA results with you.
    Also be sure to upload to other sites.

  10. Thank you, Kitty! I wondered about the generational issue. Now it makes sense.

    I’m the only grandchild alive, and my dad was an only child.

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