Confusion over Life Expectancy

A week or so ago I went to an excellent presentation at Gateshead Central Library entitled Jane Austen’s Ladies of a Certain Age by a York-based outfit called The History Wardrobe. The presenter, Lucy Adlington, a talented actress, really knew her subject, and she entertained and educated us in equal measure – with, for me, one exception. That exception was the old chestnut of Life Expectancy – she mentioned that Jane died at 41, but implied that this was normal for the period because life expectancy was very low! I felt my hackles rise as I knew this to be misleading in the extreme! This is a trap which catches out many people, even eminent historians, and, quite frankly, they should be ashamed of themselves.

Coincidentally I’d read something similar just a few days earlier, also in the context of Jane Austen’s life. This was in a piece for schools from the Jane Austen’s House Museum entitled The Manners and Customs of life in Jane Austen’s time:

She began serious writing in the 1790s at a time where at least half the nation of Great Britain was under twenty one years of age. Life expectancy back then was about thirty seven years. Although Jane Austen’s one sister and six brothers all lived surprisingly long lives, into their fifties and well beyond, she herself lived only four years longer than the life expectancy for the period, reaching just forty one years of age at the time of her death.

Here again the author is implying that Jane’s life-span was normal for the time, while her siblings had “surprisingly long lives”. Misleading, to put it kindly.

The confusion stems from three factors.

  1. “Life expectancy” is the mean (average) age at death of a population.
  2. A lot of children died in the 19th century.
  3. “Life expectancy” is not a fixed quantity; it varies with age.

Life Expectancy in the early 19th century may well have been 37 years, but that doesn’t mean that everyone expected to die at the age of 37 or shortly thereafter. There would, of course, be a range of ages at death, possibly a wide range, some lower than 37 and some higher. All we know is that when all those ages were added together, and that sum divided by the number of people, the result was around 37.

Now take into account the fact that a high proportion of children died before they reached their first birthday, many others failed to reach the age of 5, and a significant number died before they reached 16. With all those very young deaths, there must have been an awful lot of elderly deaths to bring the average age at death up to 37 .

That brings us to the idea that Life Expectancy varies with age. The term “Life Expectancy”, as normally used, is short for “Life Expectancy at Birth”. When Jane was born, her Life Expectancy was indeed 37 years, but once she’d reached adulthood, all those mean-reducing child deaths ceased to be part of the equation,  and her Life Expectancy was consequently very much higher. Indeed, at 21, she  could have expected, on average, another 40 years. By the time she reached 30, she could have expected, on average, another 35 years, taking her life expectancy up to 65.

All these figures, once again, are averages, and we’d expect a wide spread of ages either side.  Jane died at 41, her brother Francis at 91 – roughly 25 years above and below the mean for anyone who reached adulthood. Nothing unusual about either – just the low and high ends of a normal range.  The most unusual thing about the Austen family was the fact that none of them died as children.

For those who survived childhood, early 19th century Life Expectancy was not much different from that of 100 years later – or indeed a hundred or a thousand years before – or even earlier. Don’t forget that, according to Psalms 90:10 (written about 2500 years ago), “The days of our years are three score years and ten”.

Of course, life expectancy at any given time was affected by many factors.  Epidemics and wars would bring the numbers down temporarily, social changes such as the move from the countryside to towns had more lasting, but still temporary, effects. On the whole, however, little changed changed from prehistoric times until quite recently, with those who survived childhood having a life expectancy in the 60s with a considerable number surviving into their 70s and 80s or more.

Childhood deaths remained quite common until the 1930s when medical advances began to remove most of the causes of early death. Now childhood deaths are, thankfully, very rare indeed, and, as a result, Life Expectancy at 21 is now not much different from Life Expectancy at Birth.  That’s probably why many find the early 19th century situation so non-intuitive.  Back then they were very different, and consequently you simply cannot take a 19th  Life Expectancy at Birth figure and apply it to adults of the period.

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