Life expectancy is one of the key statistics in human wellbeing. However, we know surprisingly little about life expectancy prior to the systematic recording of births, deaths, and marriages, which began in England in 1538 with the establishment of parish registers. Many other countries started recording this data, but later in the 16th Century (or even later).
So, I was really interested to read this 2017 article by Neil Cummins (London School of Economics and Political Science), published in the Journal of Economic History (ungated earlier version here). They use family tree data on the European elite across multiple countries collected by the LDS church. As Cummins explains:
The church has been at the frontier of the application of information technology to genealogy and has digitized a multitude of historical records. Today they make their research available online at familysearch.org. The records number in the billions. The source of the family trees used here are the online databases at histfam.familysearch.org, a collaboration between the LDS church (familysearch) and individual genealogical experts.
The sample size is large:
The family tree records used here contain 402,204 unique date descriptions... Of the 1,329,466 individual records, 167,266 have a birth year between 800 and 1800 with an associated age at death. Of those, 115,650 have an age at death over 20 and 76,403 have a specific date of death.
Cummins uses the data to estimate the length of life of the European elite, after dealing with some tricky data issues (such as 'heaping' of dates in years that end in '0'). The resulting dataset does a good job of picking up changes in lifespan resulting from plague years and from violent battle deaths. On those points:
First, plague, which afflicted Europe 1348-1700, killed nobles at a much lower rate than it did the general population. Second there were significant declines in the proportion of male deaths from battle violence, mostly before 1550... Before 1550, 30 percent of noble men died in battle. After 1550, it was less than 5 percent.
However, more interesting is the trends in lifespan over time, where Cummins finds that:
...there was a common upwards trend in the adult lifespan of nobles even before 1800. But this improvement was concentrated in two periods. Around 1400, and then again around 1650, there were relatively sudden upwards movements in longevity.
Those changes are captured in panel (a) of Figure 8 from the article:
The figure plots average life expectancy in 50-year bins. Life expectancy hovered around 50 years (or slightly higher) from 800 to 1350 C.E., then jumped up to about 52 years in 1400 C.E., then to over 55 years in 1700 C.E. Cummins isn't able to offer a reason as to why those increases happened at those times, and notes that:
No conclusions can be drawn as to why adult noble lifespan increased so much after 1400. No known medical innovations in Europe before 1500 could be responsible... Nutrition, in terms of calories consumed, also cannot explain this rise. These elites could be expected to have always filled their bellies.
Finally, Cummins shows a clear geographical gradient in lifespan:
I find that there were regional differences in elite adult lifespan favoring Northwest Europe, that emerged around 1000 AD. While average lifespan in England in 1400 was 54, in Southern Europe, as well as in Central and Eastern Europe, it was only 50. The cause of this geographic “effect” is unknown.
So, while interesting, this paper leaves a lot to explore in terms of the reasons for changes in the lifespan of the European elite over this time period. There are also open questions about the lifespan differences between the elite and the rest of the population, as Cummins' results imply that the Black Death had a much lower impact on the elite than the rest of the population, which differs from the conclusions of much past research. As I've noted before, we need to understand more about lifespan inequality. Clearly, there is more work necessary in this area.
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