Jewish Cousins – part 2

I wrote in a posting earlier this month (*1), that when I loaded my DNA results into the MyHeritage.com website that they found 7000 possible matches for me and that many of them were in Germany, Israel, and other places. But when I started to do further investigation into all these matches (which were at the 3^rd cousin level), I could not verify any of them as actually being anywhere in my family tree.

Upon further checking, it appears that nearly all of these possible matches were to individuals who were 90%+ Ashkenazi Jewish, i.e. they were Jews of eastern European origin. Apparently the MyHeritage software does not do nearly as good a job at determining the level of match here. As I looked at how I might be related to some of them, the software said that we had hundreds of cousins in common – anywhere from 300 to 1000 common cousins depending on the individual. And while these “common cousins” were at the 3^rd cousin level for me, they were at the 1^st cousin level for the other person.

Another blogger put it this way (*2):

But DNA testing for genealogy purposes poses a special problem for Jews, often called the Ashkenazi Problem: Jews tend to marry Jews, and Jews who do not marry Jews tend to drop out of the Jewish community, and we have been doing that for so long in such a small population that we all tend to have a lot of DNA in common. The technical term for this is "endogamy," or in other words, inbreeding.  As a result, one study found that the average Jewish DNA tester matched 54% of all testers with any Jewish heritage!

Each instance of intermarriage makes it appear that a relationship is closer than it really is – so while I and another individual may actually be something like 10^th cousins, the DNA matching process might flag it as our being 3^rd cousins. Thus, unless I can find an actual common ancestor with any of these individuals, the only thing I can say for certain is that we both have a common Jewish ancestor somewhere back in history.

I don’t have the time to sift through this list of 7000+ possible matches to find the real matches – and in fact most of these individuals do not have family trees to look through anyway. So, except for the single individual who was matched at the apparent 1^st/2^nd cousin level (and who in fact was a 3^rd cousin), I guess I’ll just chalk this up to a learning experience.

Notes:

*1 - http://ramblinrussells.blogspot.com/2018/04/jewish-cousins-german-cousins-and-more.html

*2 - http://jewfaq.blogspot.com/2017/04/