How many 4th cousins do you have?

How many 4th cousins do you have? Probably nobody in the world can answer that question.

I have met and contacted a number of 4th cousins, or their grandparents. So it makes me think of the fact that we all have a number of 4th cousins floating around and we have no idea who or where they are.

A 4th cousin is somebody who has the same great-great-great grandparents as you do. Which is the first difficulty. Most people cannot name their great-great-great grandparents, certainly not all of them. Even I, who have done thirty years of family history research can only name 17 of my 32 triple great grandparents. One of the reasons I contact 4th cousins is to try to inform them of their ancestry that my research has uncovered. When I was a kid, my grandparents could usually only name their own grandparents. From that original list of 31 ancestors, I have found another 748 ancestors in my family tree (quite often thanks to the work of others that I tie into), 559 on my dad's side, and 189 on my mom's side.

But, if you could know, how many descendants would those 16 couples have? I decided to count what I have found out. In my all-paternal line my triple great-grandparents had 13 kids, 72 grandkids, 221 great-grandkids (just try remembering all those birthdays), 376 g-g-grandkids, and 521 g-g-g-grandkids. To get 4th cousins, I then need to subtract the descendants of my own great-great grandparents (because those people would be 3rd cousins or less). There are 41 of those, leaving 480 (!!) fourth cousins from that line!

For my other lines though, I had much lower numbers, including zero from one line and one from another. In the zero line, that couple had 5 children (one of which was my ancestor) 19 grandchildren (9 of them from my ancestor) but then the 19 great-grandchildren that I knew of were from my own branch of the family. The others stayed in Switzerland and I only had Swiss records to 1870.

So last weekend I did a flurry of research to see if I could find more 4th cousins. And I did. I found 54 more people in my Hart line, 32 more in my Gasser line, 18 more in my Diehl line, and so on. Then, ironically enough, even though I wasn't looking, I found 22 more people in my paternal line.

So, my total that I know of now from 9 of 16 lines, is 717, an average of 102 per line if you figure that two of my lines are very incomplete (with 0 and 1 fourth cousin). Considering the incompleteness of my data, 150 per line is a reasonable estimate for a LOW guess. I mean, ten years ago I had 393 known descendants in my paternal line, and today I have 521. Finding another 128 in other lines would bring my average to 230. So, I think 150 is a bare minimum. Taking that number for 16 lines would mean a person has, in general, at least 2,400 fourth cousins.

Of course, relationships don't stop with 4th cousins. People have 5th cousins, 6th cousins, and so on. The further you go, the more diluted the relationship. Still, I have had some encounters. Volunteering in a youth center in 1990, one of the first kids I met was Kevin. It turned out later, that he was a 4th cousin once removed. Teaching class in that same town, one of my students was a 5th cousin. That connection I knew about and told her on the first day of class. Another person that I knew since 7th grade turns out to be an 8th cousin on my mom's side. Even more of a twist was my discovery that one of my sister's boyfriends from junior high is an 8th cousin.

Sometimes in family history you find connections that you do not want to find. I mean, it is cool to be distantly related to FDR, Humphrey Bogart, Thomas Edison, Frederick Law Olmstead, Sinclair Lewis, Norman Rockwell, Ben Affleck, Cole Porter, John Forbes Nash, Tom Seaver, Anthony Perkins, Story Musgrave, and Sam Shepard, et. al. It is not so cool, depending on your politics, to be distantly related to Sarah Palin and George W. Bush.

Still, we all have that mix of famous and infamous in our family trees, because, of course, the whole human race is interconnected and distantly related. If one could know their 8th cousins, those would descend from 512 couples. I can only name 65 of those 512 in my own ancestry. The number of descendants is astounding to me. In one family I know well, the Loomis family, I have records of 8 children, 88 grandchildren, then 407- 1,472- 4,058 - 9,169 - 16,032!! And that is not a complete count.

But not every family was that successful at producing descendants. But with 16,000 after seven generations, seems like you could figure a low average of 5,000 after nine generations. Which would give most people at least 2.5 million 8th cousins.

Say hi to the family.