The impression I received from reading the article was that no DNA research was actually used and the genealogy details used were sourced from people who had submitted their genealogy details with certain filtered exclusions. I'm not sure why they say "To try" and although there may be a present link between education/occupation and longevity the process described extends this 'link' back to 1600.
To try and untangle the role of nature and nurture in longevity, the researchers built a model and trained it on a dataset of 3 million relatives born between 1600 and 1910 who had lived past the age of 30. They excluded twins, individuals who died in the U.S. Civil War, World War I and II, or in a natural disaster (inferred if relatives died within 10 days of each other).
The researchers verified that the dataset was representative of the general U.S. population's education level by cross-checking a subset of Vermont Geni.com profiles against the state's detailed death registry.
My father extensively researched our family tree and managed to get records back to 1791 in Ireland. It's quite fascinating stuff.
Due to Irish naming conventions of the period, i.e. first son name after the fathers father, second son named after the mothers father and the third son named after the father, the names of the earliest persons father and grandfather can be identified even if no records are available. The same convention is used for female children via mothers and the fathers/mothers mothers names.
A genealogy also existed for the main branches of the family between circa 880 and 1580 and several surveys also named the heads of families and their locations in the 17th century so data could be generated for gaps leaving us with only 2-3 generations where we were unable to place names to our direct ancestors. Additionally, as our family had no 'famine designation' (a name added on the end to distinguish between separate branches i.e. Cooper, Peeler, etc among many other more distantly related family groups with the same name in the same area) we could also deduce that our family was the first to arrive in the area (the mountains between Tipperary and Limerick) after the Cromwellian confiscations in the 1650's while the others arrived later.
Interesting enough the average age (with no exclusions) between father and first son in the ancient lineages between 880 and 1580 and that in the period between 1791 and 1959 (when I was born) where we have actual records were both 36 years indicating that the basic family longevity remained consistent for over 1000 years.
My great great great grandfather was born at the start of the potato famine, married at 40, emigrated to Australia during the american civil war and passed away in 1901 aged 81. Incidentally the majority of my ancestors main occupation was 'farmer' and my father tells me that my great great great grandfathers longevity was due to the fact that the soil on his farm wasn't suitable for growing potatoes so the family ate other vegetables that would be considered pig food by people in lowland areas where potatoes could be grown.
Also being a 'farmer' doesn't necessarily exclude you from being educated as we have tracked down Irish Catholic leases (31 years or 1 English life) held by 2 brothers of a direct ancestor in 1791 and both signed their names (not with an X).
So basic averages (like my recent NEO posts) may give rough generic data but there can be exceptions that vary greatly from these generic averages due to certain conditions in certain places in certain times and it is more likely that these exceptions are the families most likely to have consistent longevity/occupation 'links' going back to 1600 i.e. they are the exception rather than the norm.
Edited by LaurieAG, 04 March 2018 - 06:02 AM.