What Do You Do When the DNA Results Seem to be Lying?

I received an email message recently that is not terribly unusual. I have received a number of similar questions before. I did reply in email, but I thought I would also write an article about it as I am sure others have faced the same “problem.” In fact, the resolution is simple, although perhaps difficult to prove.

This is the email message I received although I edited out the name of the person and the name of the DNA testing company in order to protect the privacy of both. In fact, this could have happened with any of the DNA testing companies:

I have a topic that has been bugging me lately. A certain DNA testing company is advertising about their “ethnicity” reports. My previous family history results show that I am over 80% British Isles and less than 5% German. However, I know that my father (he had his test done, too) is almost 50% German/Czech. Our family history research also shows that his father must have been close to 100% German. 

I understand that I get what I get – not an exact % split of DNA but a roll of the dice. However, their commercials imply that you will know that you are not German if the DNA test shows no German in the ethnicity profile. What gives? 

I think they are misleading people with those ads. What’s your opinion? (I also think their ethnicity reports are not 100% accurate.) 

Thanks for your consideration of my question, and thanks for your newsletter. It has led me to several invaluable resources over the years of family records I would have never found otherwise.

Here is my (slightly edited) reply:

There are at least three possible reasons that the DNA results show non-German ancestry of the individual in question. The most obvious reasons are:

1. A mistake at the DNA lab where your test sample was accidentally swapped with a sample from someone else.

2. Even brothers and sisters (with the same parents) normally do not receive exactly the same DNA from each parent. It has been compared sticking a ladle into a container of soup on the stove. One person might pull out “components” of 40% British DNA, 35% German DNA, and 15% Swedish DNA. Meanwhile, that person’s brother or sister might use the same ladle and dip it into the same container of soup, but perhaps will pull out 65% British DNA, 25% German DNA, and 10% Swedish DNA. Almost no one ever receives exactly 50% of their DNA from each parent, the mix is almost always more or less than 50% from each parent. To be sure, the total is always 100% but almost never exactly 50/50.

3. Did his ancestors REALLY come from Germany and nearby regions? Sure, that’s what the records show, but were those REALLY HIS ANCESTORS?

One “mystery” that turns out to be very common in DNA research is that someone was quietly adopted into a family some years ago without paperwork and other family members kept it quiet (this happened often; I have several examples in my own family tree). 

Another possibility is what is humorously referred to as a “non-marital event.” That is, someone in your family tree spent at least one night with someone other than his or her married and documented spouse.

While we all smile when we say “non-marital event,” the fact remains that such liaisons were common throughout the years, even in the 1700s or later.

There is a book called “Sex in Middlesex” by Roger Thompson. The book is available from Amazon and probably other bookstores. It may be found on Amazon by searching for ISBN 0870236563.

In the book, Roger Thompson describes various sex “crimes” that were tried in court in Middlesex County, Massachusetts, in the early to mid-1600s: “Sex in Middlesex pulls its facts from the Middlesex County, Massachusetts, court records. Eleven chapters discuss court cases by categories such as “Fornication: Detection and Evasion,” “Courtship and Patriarchal Authority,” “Pregnant Brides and Broken Promises,” “Unfaithful Wives,” “Unfaithful Husbands,” and “Community Control.” Statistical charts include “Geographical Incidence of Sexual Misdemeanors [1649–1699]” (the winner is Charlestown with 60, next was Cambridge with 31), and “Incidence of Conviction for Sexual Misdemeanors.”

I am sure such events were not limited to one county in Massachusetts. Anyone digging through old records can find many similar court cases everyplace else. While we commonly think of our ancestors as straight-laced Puritans or others who would never do such things, the fact remains that they were human beings with the same weaknesses and challenges that modern-day humans face. The court cases reveal that unmarried couples or couples who were not married to each other had extra-marital affairs probably at least as often as do today’s couples.

So, were your grandfather’s REAL ancestors from someplace other than Germany? Or did one of your ancestors have an extra-marital liaison that you do not know about? It is possible that the DNA results you have received may prove something about your grandfather’s ancestry that perhaps even he didn’t know.

Luckily, the solution is simple, although a bit expensive. Have another DNA test taken by another DNA lab. (I have had my DNA tested by five different DNA labs, and I know of other genealogists who have tested with even more labs than that.) See if all the test results agree. In my case, the test results are similar but never exactly the same. 

If only one test result shows non-German ancestry, then the first assumption probably is correct: the lab made an error.

However, if all the DNA tests say that he had little to no German ancestry at all, then I would suggest that you have some new family history challenges ahead of you!

I can hear a collective gasp from everyone reading this article: “What? Not MY ancestors!”

But it was true many, many times.

So here’s a question for everyone else: What’s in YOUR DNA?