As I was thinking about Elsie (Shackley) Benson, it occurred to me that she may have died childless. I know that Carrie (Pinkham) Corson had two sons, one of whom died at age 40 without kids, and another who lived to 80, but about whom I know nothing. That means, I can only be certain that my great-great-grandparents George and Olive (Hurd) Pinkham had two children through whom they had descendants. I can ballpark them as being roughly between 75-100 people. That's not a lot for two people born in 1843 and 1851, respectively. And even if we top it off at 100 living descendants, that means we've only got one genealogist among us. My late cousin Dorothea knew things about the family, but wasn't a genealogist per se. My other late cousin Janice asked for information that I had gathered, so she had some interest as well.
I then realized that George Pinkham was only one of three children for Luther Hale and Mary Chamberlain (Wallis) Pinkham to have children. It means that these people, one of whom remains a documentally-challenged brick wall, may only have 300-500 living descendants. That doesn't seem like many for people born in the 1810s, now 200 years ago. I'm guessing there's no cousin who's going to be coming to my rescue with the DOCUMENT to help me.
If we take a low number of average children having children, say 3 per generation, then there should be 243 in my generation and 729 in my nieces' and nephews' generation. If you assume that the last three generations are all living that's a total of 1,053. So, I think we [this Pinkham line] are below average propagationally. If I take the numbers I actually know:
Luther had seven sons, three of whom died in childhood. Of the four left, one died childless. Those three produced sixteen children. I know that George only had four of his six children live to adulthood. Nathaniel also lost at least two of his eight. So, at most, there were twelve grandchildren of Luther Hale Pinhkam who could have had children of their own. George's grandchildren numbered eleven of which one died in childhood, two died childless, and two can't be verified. Even with everything I've ever posted on the Internet or published in print, no one from Nathaniel or Seth Pinkham's [George's two brothers] families has ever contacted me. Indeed, the nearest relative to have contacted me on this side of the family was from a sister of Luther Hale Pinkham.
So, I will add another dimension to brick walls: Lack of descendants. I think you need to hit critical mass of descendants to generate at least several genealogists in separate lines who can then pool their resources. Basically, I've been flying solo on the Pinkhams my whole life.