FW: FW: fourscore...

[Frank Abate]

In a reply to Ed K re infant mortality, A, Murie said:

>>
The corollary would seem to be that since the infant mortality has dropped
so greatly, the average lifespan "ought" to be even more greatly extended.
If ancient and remote societies  had many examples of people surviving into
their eighth, ninth & tenth decades, it suggests that modern urban
societies must have signigficant life-shortening elements, since we do not
see such huge gains.
<<

Statistically this would not pan out.  Infant mortality rates, while a good
measure of the effectiveness of a given health care system, do not have a
large effect on overall life expectancy, as the vast majority of infants do
live past their first year (if we can define that as infancy).  So even a
doubling or halving of infant mortality would have only a slight effect on
the overall life expectancy for a given population, as the number of
individuals involved in infant mortality is relatively small.

So the reason that ancient societies had many examples of people living into
quite old age is that people did and always have, in urban and more settled
environments.  What really effects the overall life expectancy is childhood
diseases (that is the big factor that has changed; see below), death from
violence and accidents (accidents on the farm or in the factory, wars,
falls, etc.), and death from various "adult" diseases.

Childhood diseases, which used to claim the lives of a high percentage of
children born, overall, in colonial and early US America, are now hugely
reduced thanks to vaccinations, inoculations, antibiotics, and other such
medical discoveries, all within the last 150 years or so.  Before that,
death between the ages of, say, 5 and 16 was quite common and not at all
surprising, even though a cause for grief in the family.  A look at colonial
and early American family records, or a walk through a cemetery with graves
from the 1700s and 1800s, would show that pretty quickly.

Another factor that has largely been eliminated in its lethal importance is
influenza, which claimed millions of lives in the US as recently as 1918 (a
major epidemic year), but which now is a relatively minor factor, re
mortality rates.  In older days a big factor was plague, but modern
sanitation systems eliminated that.  Note that whenever there is a major
interruption of sanitary systems owing to earthquakes, floods, or other
natural disasters, the big early problem is cholera, dysentery, and other
sanitation-related diseases.  Control those and you make a big dent in
mortality rates.  Control that as well as influenza and childhood diseases
and general nutrition, and you see the life expectancy, as an average, climb
meteorically.

But it remains true that if you survive to adulthood, and are not working in
a dangerous or very physically challenging job, you have a very good chance
(save for accidents and wars) of making it into your 70s, 80s, or beyond.
This has long been the case, since ancient times.

Frank