Explore your ancestry with a free trial!

Research Tips

Using Negative Evidence to Prove Relationships in Genealogy

🎧 Listening to the Podcast on YouTube or iTunes.


There are brick walls in genealogy, and then there are black holes. Sometimes, you get to an area where the records were either destroyed, or were never kept in the first place, and it’s next to impossible to get around the barrier and still have a family line with any degree of certainty to it. Without records, all you will be doing is guessing, or relying on someone else’s online tree with no listed sources and dubious truthfulness. Or, will you? Believe it or not, it is possible to add generations to a family tree line that has fallen into the abyss. You don’t necessarily need records to do it. What you need is negative evidence.

Explore your ancestry with a free trial!


What is negative evidence? It is using the absence of records to your research advantage. You determine family relationships where there are no existing records that document them by examining what is not there. This technique is used by advanced family historians and expert genealogists but is not so well known by others, especially those at the beginning or intermediate stage of their genealogy skill building. It’s a surprisingly effective technique at busting through those brick walls and getting around those black holes, though, so it is well worth learning and applying to your research activities. You’ll be amazed at the results it can produce.

Let’s say you are researching a family line that ends abruptly, either because of lack of records or because of too many people with your ancestor’s name in one place. You don’t have to be stuck. You just need to look at what is not there and compare it to what is there. It’s much simpler than it sounds.

Say you have an ancestor whose line ends with your 5x great-grandfather in Georgia in the early 1800’s. There were many early Georgia courthouses that burned, taking all useful genealogical records with them. You have no records to go on, and you have no idea who that great-grandfather’s parents were or any obvious way to discover them. The courthouses were wooden in those days. Some counties even had courthouses burn more than once, and had to keep rebuilding until we got the sturdy buildings with safe record repositories we have today.

Virginia, on the other hand, is notorious for not having any 18th or 19th-century records at all in some places. Colonial New England is a place where you are likely to find five or six people with the same first and last name as your ancestor. And with so many people around them also having similar names (the Puritans were not innovative namers), it can be like untangling all the cables behind your computer to determine who belongs to which family. There are all kinds of reasons you may run into a brick wall with your genealogy.

But, keeping with the example of the five-times great-grandfather in Georgia with no surviving records from the period, let’s take a look at how you would use negative evidence to locate his parents. Is this grandfather in the 1850 census, or have you found a headstone for him? Anything that lists his date of birth or approximate age? If you’ve gotten as far back as him, you presumably have at least a little bit of information on him. But, there are no records that list who his parents were. They are the mystery. If you can find them, you can break through the brick wall.

Begin with his age or approximate age. Then, look at earlier census records from the same town (and then the same county, same tri-county area, same state, same tri-state area, and finally, the entire country, if you don’t find anyone of the same last name in his last known town of residence). How many people do you find with his same last name? Look at the household records for these people (census records before 1850 only list the head of household, and genders and age ranges for other people living in the house). Do any of them have a boy living with them who falls within your grandfather’s age range? Look for the ones who don’t. Eliminate them. By using the negative evidence of who can’t possibly be your grandfather’s parent or relative, you narrow down your possibilities to who could be.

You may end up with one possibility, or more than one. Take your possibilities, and expand your research, then narrow it down once again. Look up state-level wills or probate records that may exist for these people. If they were kept at the state instead of county level, they might still exist. Do any of these documents mention your ancestor as a son or other relative? Maybe your ancestor has a common first name, and more than one will you look at mentions a relative of this name. What is the date the will was proved? Was your ancestor a minor at the time, or grown up? If he was a minor, you could eliminate all the ones who mention an adult. It’s the same thing if he was an adult, and you only find mentions of minors. If your ancestor isn’t mentioned at all, maybe he received his portion of the estate before his parent died. Look at the other people mentioned in the will, including the executors, then research them. You might locate mentions of your ancestor in any documents they left.

If it’s just a probate list, look at who administered it. They might be a relative. Research them to see if you can find a mention of your ancestor in any of their documents.

If there are no wills available, or probate records, look for old newspaper records, church records, tax records, and land records. These are all things that were kept at some level other than the county, and so would have survived a courthouse fire. Look for mentions of the people you have isolated as possibilities for your grandfather’s parents, then comb through those records that mention them for some clue to their relationship to your grandfather. If you find none, search the records pertaining to other people mentioned in these documents.

By determining what is not there, you can narrow down what is, and then take away even more potential evidence by doing deeper research, until you are eventually left with the person or couple who is the only logical parent or parents of your ancestor. Using negative evidence this way, you will find them.