The other day I went to the library to pick up a book I had on hold. I found the book and a magazine on the shelf waiting for me. I checked them out and was casually flipping through the magazine while I waited for my daughter’s choir practice to wrap up. In the back of the magazine I saw a picture that would not have been familiar to me just an hour earlier. It was a picture of the book that I had just checked out along with the magazine. What a coincidence!
Well, it isn’t really a coincidence. I had the book on hold because I had heard an author interview and it sounded interesting. Authors usually do interviews about their books because the books have just been published. Recently published books are more likely to be found in full-page advertisements at the back of a magazine than are other books. It is also more likely for a person who is interested in a book to also be interested in a magazine whose subject matter means that it is a good place to run an ad for the book. My choice of that book and that magazine was not random. I do have to admit that it is amusing that the book in question is The Improbability Principle, a book about the nature of coincidences and why we should actually expect them.
What is a Coincidence?
What genealogist hasn’t run into what seems like a remarkable coincidence when researching their family? Some of the toughest things for genealogists to handle are those “coincidences.” Some coincidences are meaningless and we need to weed them out and disregard them or they will waste our time and even lead us to wrong conclusions. Other coincidences are meaningful and are major clues. How do you tell them apart?
The first thing to do is to define what we really mean by “coincidence.” The parts of the word simply indicate that something happened at roughly the same place and time as something else. That doesn’t really do it though. Coincidences need to have some sort of surprise factor. There can’t be a cause and effect relation. If you throw a rock at a window and then hear the sound of shattering glass, you would not call it a coincidence. If you threw the same rock at a tree and heard the sound of shattering glass just as you saw the rock hit the tree, that you would probably think of it as a coincidence—and a pretty strange one at that. A more genealogical example might be finding a man with a very unusual name in a small town and then finding a different man in the same town with the same name fifty years later. Coincidence or a child named for his grandfather?
Another set of occurrences that we shouldn’t really think of as coincidences are things that have the same cause. It isn’t a coincidence when the snow melts and the first plants start to come up in the spring. Both are brought on by the arrival of warmer weather.
Events that don’t have any apparent connection don’t qualify as a coincidences either. You would not think “Wow, what a coincidence!” if the dog two doors down starts to bark at the same moment you took a sip of tea.
Coincidence to Clue in Genealogy
If we find something that looks like a coincidence, what should we do? Can we immediately conclude that we have something meaningful and go on from there? No, given the number of people who have existed in the last few hundred years and the number of things they did that were recorded, there is plenty of room for chance to make things seem to be connected when they are not. In fact, it would be strange if chance did not make a few things seem to be connected when they are not. Lots of things happen and some of them will randomly seem to be related. Can we immediately conclude that our coincidence is meaningless? No, it might be that what looks like two unconnected random facts are actually connected by cause and effect. One may have caused the other, or they might be the results of a common cause or share some common factor.
One question that needs to be asked is, what is the chance that there is something behind this coincidence? Figuring that out means digging into the situation. If you just discovered that one of your ancestors was in the Civil War and you look at the names of the other men in his unit and see a name that looks familiar, is it random or meaningful? If the name is familiar because someone of that name lived in the same town that you suspect your ancestor lived in before the war, then it might be meaningful. Nevertheless, you could only conclude that after you learn that Civil War units were usually made up of men from the same area. You can also think about what is the chance that it is a random coincidence that two people with the same unusual last name are from the same place? Is the population of that place 50 or 50,000? Is the name unusual in general but common among an ethnic group that is numerous in that area? All of these things help to decide if the coincidence is worth pursuing.
The other question that you should ask is, “If this was more than a coincidence, how could these things be connected?” There might no way for them to be connected or there might be several. If there is no way, then it is time to go on. If there is a way or even several different ways, then you need to think about the next question—”What would a possible relationship between these things mean?” What kind of evidence might exist if any given possible connection was correct? Once you are able to ask that question, you have turned a coincidence into a clue and that is cause for a little celebration.