Engineering Ethics Blog: Technology, Demography, and Destiny


Most people, including most engineers, suspect there is some
relationship between the advances in transportation, communications,
sanitation, and health care brought about by modern science-based engineering
on the one hand, and the tremendous and rapid growth in world population that
has taken place since 1800 on the other hand, when there were only an estimated
1 billion people worldwide.  Now there
are about 7 billion.  Something happened
beginning a couple of hundred years ago that had never happened before in the
history of the world, and the effect was to make population soar at an
unprecedented rate. 


Whatever your opinion on whether this is a good thing or
not, demographer Paul Morland has done us all a favor by writing The Human
Tide:  How Population Shaped the Modern
.  The job of a demographer is
to study the details of human population statistics:  birth rates, death rates, migration, and
their effects and causes in relation to economics, politics, and the rest of
life.  So far, so dull, you think?  Not in Morland’s hands. 


It turns out that no matter what nation or ethnic group
you’re talking about, the encounter with modernity (which mainly means modern
methods of transportation, communication, etc.) gives rise to what Morland and
his colleagues call the first type of “demographic transition.”  For most of human history, population was
limited both by the scarcity of food and the brevity of human life due to disease
and starvation.  In Biblical times, for
example, nearly everyone lived on a farm, and married women typically had four or
more children so that enough of them would live long enough to become useful
farm hands.  Everyone lived in what
Morland calls “the Malthusian trap,” named after the English cleric
and scholar Thomas Malthus (1766-1834).  Malthus
said that any increase in the food supply will only tempt people to have more children,
and the increased number of mouths to feed more than makes up for the original
increase, meaning that near-starvation will be the typical lot of humanity into
the indefinite future.


But Malthus had no way to tell that the coming century would
bring with it technological improvements in agriculture (steam and gasoline
tractors), transportation (railroads, automobiles), public sanitation (clean
water, sanitary sewers), and health care (improved pediatric and geriatric
medicine), all of which enabled first England, then parts of Europe, the U. S.,
and other countries to escape the Malthusian trap.  And it turns out that everybody escapes more
or less the same way, although the timing varies from place to place.


First, falling infant mortality and increasing lifespans
lead to a tremendous boom in population, as women keep having those four or six
children they’ve always had, but most or all of them now survive to adulthood
and live much longer lives, into their fifties or sixties.  After a generation or so, especially if the
cultural setting encourages literacy and advanced educational opportunities for
women, they stop having such large families. 
The means by which this happens is something of a mystery, as it
involves decisions and behavior that are not easily observed on a mass
scale.  But in culture after culture,
country after country, even in religions as different as Christianity and
Buddhism, the first demographic transition works more or less the same way.


Once the average family size comes down to replacement level
(typically about two and a fraction children), some countries move on to what
Morland calls the second demographic transition:  a further reduction in the birth rate below
the replacement level.  This does not
immediately result in an overall population decline, because large numbers of
young women may still be growing into childbearing age, immigration into the
region may be significant, and many other factors can intervene as well. 


But in some cases such as Japan, the birth rate is extremely
low, the overall population is declining, the median age is among the highest
in the world, and it is estimated that up to 30,000 elderly Japanese die alone
in their homes every year, giving rise to a whole industry that specializes in
removing abandoned bodies. 


This is not necessarily the fate that all modern
industrialized countries face.  Some
countries such as Sri Lanka seem to have stabilized themselves at a comfortable
balance with replacement-level birth rates, reasonably long lifetimes, and a
fairly constant population figure.  But
every country that encounters modern technology eventually goes through at
least the first demographic transition.


The book also made me wonder what relationship should obtain
between the way large groups of people behave on average, almost regardless of
culture or faith, and the ideals of certain faiths, particularly
Christianity.  Morland points out that
the universality of demographic transitions happens because nearly everybody (a)
would rather live longer than die young, and (b) wants the same for their
children, however many there are.  So
when the technical means become available to achieve these ends, a society
adopts them, and eventually quits having six or eight kids per family unless
there are extremely strong cultural or religious reasons to keep doing so.  Morland does mention exceptions such as the
Jewish Haredim ultra-orthodox sects and Christian groups such as the Amish, who
tend to have large families whatever their circumstances are.  But unless such convictions become widespread
in the general population, it’s unlikely that large families will become the
norm in modern industrialized countries.


Is that a moral failing? 
Admittedly, there is a wide spectrum of opinion or conviction even
within Christianity, ranging from liberal groups that favor abortion rights to
conservative elements of the Roman Catholic Church that look not only upon abortion,
but on any form of birth control other than “natural family planning”
(formerly known as the rhythm method) as sinful.  So in one sense, it depends on who you ask.


What Morland taught me is that while demography isn’t all of
destiny, it does have a lot to say about the histories and trajectories of
regions, countries, and even continents. 
Sub-Saharan Africa, for instance, is the only place where the majority
of countries are still undergoing their first demographic transition, with
extremely fast population growth that has not yet been dampened by that
mysterious collective decision to have fewer children per mother.  Whether countries such as Nigeria end up
managing their transition well and stabilizing like Sri Lanka, or whether they
get mired in the chaos and civil strife that seems to accompany having lots of
young unemployed men in your population, is a question that remains to be


But when the answer comes, people like Paul Morland will
have helped us understand how the invisible hand of demography contributes to
history in general, and the history of technology too.


Sources:  Paul Morland’s The Human Tide:  How Population Shaped the Modern World
was published in 2019 by Public Affairs Publishing, New York.

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