Friday, January 9, 2015

What others have to say about Life Expectancy through history - and my take on that

1) Φιλολoγικά/Philologica : "in a time when most people died at an average age of 35" ; 2) What others have to say about Life Expectancy through history - and my take on that ; 3) Longevity in Selected Ancestry and Inlaws of Eleanor of Montfort ; 4) Tudor Times Demographical Stats ; 5) How Many Hours are we Talking About, and How Heavy? ; 6) New blog on the kid : When "Answers" Paint Middle Ages Black ; 7) Creation vs. Evolution : CMI Provided some Lifespans of the Past ; 8)Other list from CMI of lifespans ; 9) Φιλολoγικά/Philologica : Medieval and Early Modern Lifespans, Again: Berkeleys and Related ; 10) Story of a Cardinal's Title with Pre-Industrial Demographics

[Will start off with a look at:] Wiki: Life expectancy

As is to be expected from such an error fraught discipline, and Wikipedia favouring the common level of culture in any field and language, with this topic as one of the worst as to English language users’ general culture, this article is not per se to be trusted.

I will return to why the following table is skewed. Meanwhile I have improved it by adding links to its sources, as taken from footnotes:

EraLife expectancy at birth (years)Life expectancy at older age
Upper Paleolithic32This is the earliest time period of fully modern (both anatomically and behaviorally) humans. Based on the data from recent hunter-gatherer populations, it is estimated that at age 15, life expectancy was an additional 39 years (total age 54).
source aDeevey, Edward S. (1960). "The Human Population". Scientific American.
source bHillard Kaplan, Kim Hill, Jane Lancaster, and A. Magdalena Hurtado (2000). "A Theory of Human Life History Evolution: Diet, Intelligence and Longevity". Evolutionary Anthropology 9 (4): 156–185. doi:10.1002/1520-6505(2000)9:4<156::AID-EVAN5>3.0.CO;2-7. Retrieved September 12, 2010.
linklink to source b
linkother link to source b
sourceGalor, Oded & Moav, Omer (2007). "The Neolithic Revolution and Contemporary Variations in Life Expectancy". Brown University Working Paper. Retrieved September 12, 2010.
Bronze Age and Iron Age26
Classical Greece28
sourceMortality". Retrieved November 4, 2010.
linkhere(100 of 159 words preview, Classical Greece not yet mentioned)
Classical Rome20–30At age 10, life expectancy was an additional 35 to 37 years (total age 45 to 47).
sourceFrier, Bruce W. (2001). "More is worse: some observations on the population of the Roman empire". In Scheidel, Walter. Debating Roman Demography. Leiden: Brill. pp. 144–145. ISBN 9789004115255.
Pre-Columbian North America25–30 (correct to "probably between 25 - 35")
sourcePre-European Exploration, Prehistory through 1540". October 5, 2010. Retrieved November 4, 2010.
Medieval Islamic Caliphate35+
sourceConrad, Lawrence I. (2006). The Western Medical Tradition. Cambridge University Press. p. 137. ISBN 0-521-47564-3.
Medieval Britain30At age 21, life expectancy was an additional 43 years (total age 64).
source"Time traveller's guide to Medieval Britain". Retrieved November 4, 2010.
linklink no longer directs to programme
source"A millennium of health improvement". BBC News. December 27, 1998. Retrieved November 4, 2010.
source"Expectations of Life" by H.O. Lancaster (page 8)
Early Modern Britain25–40
Early 20th Century31
source"PowerPoint Presentation" (PDF). Retrieved November 4, 2010.
sourceOur Special Place in History
linkshould have been here (not found either on link or by search function)
2010 world average67.2
sourceCIA—The World Factbook—Rank Order—Life expectancy at birth

The last estimate is probably pretty correct – 67.2 years world wide in 2010. By CIA. When I look at link I get to another page of stats – for 2014, estimates. Life expectancy at birth ranges from 1 Monaco 89.57 years to 223 Chad 49.44 years. I have no means to make the medium but the median is 112 Bulgaria 74.33.

So, the “statisticians of the past” want us to believe Middle Ages were worse off than Chad today? Perhaps slightly possibly if life expectancy at birth (medium life length) is taken into account and abortions (as in the work of CIA) not counted as very short human lives.

When it comes to the past, we can evaluate each according to our principles how likely it is that a story (with claims to have happened, i. e. not an entertainment fiction) is true, what source we have, what general credibility it has, how many we have, how well secondary sources evaluated primary ones like eye-witnesses, how credibility is affected by miracles or by partiality etc.

But for a time when statistics were not made, or those that were are not preserved, we cannot reconstruct the real statistics. Besides, if they vary so much now depending on where you live, why should “bronze age” have had a uniformly low one?

And how can we guarantee the life expectancy of Amerindians in North America as observed today those with traditional lifestyles in US and Canada have not been adversely affected by oppression? And by fact most places where a palaeolothic population would move for better food when times get worse are often taken by whites. Why should Palaeolithic in Dordogne have been exactly like that for life expectancy?

The wikipedian source for Roman Empire life expectancy is a discussion from an essay by one of several demographists. One thing he claims is that Montesquieu was wrong about how populated Gaul was in Roman times – why would we trust the ideology saying Roman populations can’t have been as high as Montesquieu claimed? He would however be somewhat likelier to know whether Montesquieu underestimated his own time. He – the demographist – also claims density of population made for “higher mortality”, i. e. for lower life expectancy at birth.

But for Middle Ages we have three sources. First is now missing. Second is from a BBC article, which I find unreliable:

"Lack of sanitation meant germs that are now easily dealt with lived everywhere.

Thatch roofs were common in the countryside (where 85-90% of the population lived) and they attracted insects and rodents.

They carried bacteria, which they deposited either on the inhabitants or the food they would eat."

I have seen thatched roofs in Dragør in use, and I gather they are there in Hungary too. In countryside not so many bacteria were available to use insects and rodents as vehicles towards destruction of humans, and those that were are likely to have strengthened immunity systems (except for oldies). In cities where bacteria were more dangerous, like bubonic plague, etc. thatched roofs were not so common. Duh!

Besides, fumigation of thatched roofs was a known technique of avoiding germs.

Of course, during the bubonic plague, a village with thatch roofs would not be the safest place, once a single plague case had arrived. Whether in man or in rat or in flea. But Middle Ages were about a thousand years and plague of 1348 was about two of them.

The third source actually does admit there is a problem as to knowledge of how long people lived outside the classes in the limelight of posterity. Wikipedia reproduces its table for English aristocracy, but omits the diversity of the basis – ranging from 7 male aristocrats between 1200 and 1300 to 800 something 1700 to 1745.

Citing wiki: Life expectancy increases with age as the individual survives the higher mortality rates associated with childhood. For instance, the table above listed the life expectancy at birth in Medieval Britain at 30. Having survived until the age of 21, a male member of the English aristocracy in this period could expect to live:

Citing source, p. 8 of Expectations of Life: A Study in the Demography, Statistics, and History of World Mortality by H.O. Lancaster: (I add ages in parentheses)

TimeNumber of males observedLife expectancy at 21
1200-13007 43.14 (age 64)
1300-1400 924.44 (age 45)*
1400-1500 2348.11 (age 69)
1500-1550 52 50.27 (age 71)
1550-1600 10047.25 (age 68)
1600-1650192 42.95 (age 64)
1650-1700 346 41.40 (age 62)
1700-1745 81243.13 (age 64)

* The low figure in 1300-1400 reflects the effects of the Black Death.
From Guy.
Explanatory note: Guy (1845) gave “expectation of life at birth” as expectation of life at 25 + 25 years that is 0e0 = 0e25 + 25, which is not admissible.

Admissible or not, what Guy tried to do was to correct the skewing of medium age of death due to infant mortality. Same thing that Lancaster does by giving expected remaining years at age 21.

As you can imagine, English aristocrats of 1200 are easier to observe than English peasants back then. They were less exposed to dirt and fatiguing toil of drudgery type and more exposed to death in battle or from battle wounds or to contamination due to wide sphere of social contacts. Which of the two was worse for life expectancy? We don’t know. We do know that hereditary sovereigns excluding those dead in battle or by poisoning and excluding obviously Charles I too, have a LOWER life expectancy than English aristocrats of these times.

As to peasantry, supposing they did live shorter lives, we still need not suppose it was like between Monaco and Chad.

So, if you base any calculus about Ancient Egypt on known Pharaonic life lengths, adding that they lived materially best and therefore longest, think again. Scribes probably lived longer than Pharaos, and we don’t know how much longer they lived than peasants.

Another lesson from the table of CIA is, you can’t take the demographics of one country and apply them to another one. Supposing there was a thing like a reasonable case for Egypt having had a life expectancy at birth of 35 years. Supposing there was also a case this was contemporary to such and such a time in Israel – that would not be a reason to just transfer the numeral across the border. Some small areas can have higher life expectancy. Japan was third from top while China was #100. If Greece was only #30, this may be because Athens has a lower life expectancy than parts of countryside. Notably Crete – unless the Cretan who told me that was a liar, as a poet said and as St Paul quoted.

The first table of Wikipedia is nearly worthless, because so many of the life expectancies are just guesses that are likely to be bad. Definitely not a reason to compare Caliphate favourably with Medieval Europe, since such a portion of our intellectuals are pro-Medieval Islam and anti-Medieval Christendom. This bias is likely to have influenced the diverse round figures up or down. On top of that, Wikipedians may have chosen low estimates for Middle Ages and high ones for Caliphate.

I am not sure if Lancaster gives an overall table anywhere like this first one. But if he does, I don’t think his numbers would agree. What he does is enumerating an impressive amount of studies right from the start.

Now, here is one - outside Lancaster's book - taking on the “they died before 40 in 9 out of 10 cases”:

By Tim Lambert

Citing in its turn for that one nearly verbatim:

By Tim Lambert

I’ll cite the more detailed latter link:

Life Expectancy before the Industrial Revolution

We do not know exactly what average life expectancy at birth was in the past (before the 19th century we can only give rough estimates). However historians think it was about 35 years in the Middle Ages or the 16th Century. (So 50% of the people born reached that age). However that does not mean that people dropped dead when they reached 35! Average life expectancy at birth was around 35 but a great many of the people born died in childhood. We don't know exactly what percentage died but if we say about 25% of people died before they were 5 years old we are probably not wide of the mark. Perhaps as many as 40% died before they reached adulthood. However if you could survive childhood and your teenage years you had a good chance of living to your 50s or your early 60s and even in the Middle Ages in Western Europe there were some people who lived to 70 or 80.

Things improved in the 18th century in Britain. Life expectancy at birth rose to about 40 by the late 18th century. Nobody is sure why. Plague died out, which must have helped. (The last outbreak of plague in Western Europe was in Marseilles in 1720). Furthermore in the 18th century eating potatoes became common, which probably improved nutrition. Improvements in 18th century agriculture may also have helped.

Tim also takes on a myth about washing in the Middle Ages, will cite both his words on that first page and his link to specific topic:

In fact there is considerable evidence that most Medieval people tried to keep themselves clean. The evidence also suggests that most people washed and changed their clothes quite frequently. They also tried to keep their houses clean. The idea that people were filthy and stunk is a myth.

The myth may have arisen because people rarely took baths. Before the 19th century it was difficult to heat a large amount of water in one go Suppose you heated a cauldron of water and poured it into a tub. By the time you had heated a second lot of water the first lot would already be cold. The Romans solved this problem by having public baths, which could be heated from underneath.

However, after the fall of Rome it was much easier to have a strip wash. In hot weather people bathed in rivers. There is also evidence that people washed their clothes quite often.

By Tim Lambert

I will highlight one source of error: Before the 19th century it was difficult to heat a large amount of water in one go Suppose you heated a cauldron of water and poured it into a tub. By the time you had heated a second lot of water the first lot would already be cold. Would depend on how large the cauldron and how narrow the tub, and how many were helping each other, wouldn't it?

Then he links to this:

Baths in the Middle Ages

In the Middle Ages there were bathhouses in many towns were people could pay to have a bath. Furthermore in Northern Europe in the Middle Ages people took sweat baths.

In the 14th century Edward III installed a bathroom in the Palace of Westminster. Other people made do with wooden tubs in their bedrooms.

Furthermore in the Middle Ages there was an important soap making industry in England (although many people made their own soap at home). In the Middle Ages people used combs and tweezers. They also used toothpicks and mouthwashes.

In the Middle Ages in monasteries streams provided clean water. Dirty water was used to clear toilets, which were in a separate room. Monks also had a room called a laver where they washed their hands before meals.

By Tim Lambert

Getting back to first table, the wikipedian one: the low life expectancy at birth is given as 31 for Britain at early 20th C. And as 30 for Middle Ages … could it be the 31 years expectancy at birth was correct (source is Thomson Prentice from WHO and Britain at 1900 was well studied) but that it had been higher in the Middle Ages? But that someone’s could not buy this and set it a year lower just to show some progress.

Actually I take a look at the source for the 31 years figure:

In 1900, global average lifespan was just 31 years, and below 50 years in even the richest countries

Oh, so it was NOT Britain in 1900 which had 31 years, but world wide! Britain then would have been like Chad now.

That means the 31 years global may reflect colonialist estimates of non-colonised populations, among other sources of error.

Lesson : when using wikipedia, unless just checking something already known, check other language versions or sources or both. ALSO: when it comes to Middle Ages or other parts of the past, do not rely on statistics unless you are sure they are no constructs, it is better to rely on texts.

Hans Georg Lundahl
Nanterre University Library
Sts Julian and Basilissa

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