April 1, 2010

David Cahill
Marvin Brown Building
Room No 330
School of History and Philosophy
University of New South Wales
Sydney, NSW 2052

Dear David Cahill:
I have always liked the Incas better than the Aztecs.  Of course as a child I and my friends were always on the side of the Indians and against the Spanish.  Ponce de Leon was considered a bit of a charming clown and Hernando de Soto won gruding respect from us.  After all, he had managed to march through Florida, and living in Florida we recognized that this was no mean feat.  Geronimo was able to do it once, but it wrecked him.  The rest we considered pretty much to be monsters. 

The Aztecs were hated by the locals.  My understanding is that the “conquest” was largely a revolution rather than an invasion, at least at first.  I suspect the Aztecs are hated still.  I was once in a private apartment in Tiajuana and noticed a print prominently displayed.  It was a heroic scene at the pinnacle of an Aztec pyramid.  A muscular young man, muscles bulging and tribal ornaments flashing, stood with maiden in one arm whilst the other arm raised a hideous weapon in preparation for doing something permanent to an Aztec priest. 

So I warmed up to your chapter “Advanced Andeans and Backward Europeans” in Questioning Collapse

I have my own take on collapse.  I have never doubted it happened because when I was growing up in Gainesville, it was quite evident to an inquisitive child that the society about me was resting on the ruins of a far richer and more numerous society that had vanished or at least collapsed not many decades before. 

My thumbnail definition of a civilization is a large group of people (more than a few hundred thus excluding bands of hunter gatherers) who are spending their lives cooperating and getting along without being part of a larger society (thus excluding things like monasteries and armies).  By this definition my observation is that once a civilization starts it will collapse in 300 years.  Of course things are more complex.  Civilization like those in Mesopotamia may consists of thousands of urban specialists while dominating an enormous number of primary providers.  Then it will be the rulers that collapse, not necessarily the people as a whole. 

The reason for this metronome like timing is quite simple.  Any large random mating population of humans will suffer a demographic collapse after three hundred years.  If it is a civilization there will not be enough capable people to maintain it.  Simply said, less easy to prove.

There are a few exceptions.  The Greeks on one occasion had a society that lasted a bit longer, but they invested a lot of power in the demes or little local communities.  Also they secluded their women so mating was not unfettered.  The Egyptians broke the rule three times, but the upper Nile is so narrow with no social prospects to east or west that the mating pool size is small for a population lacking bicycles or better.  England is a special case I can go into if you like.

The cause seems to be purely genetic.  I presented my evidence at a genetics conference last month buttonholing maybe two dozen professionals.  I was challenged by a few, but not one could find a real problem with what I had to say except that it was unexpected.  If you wish to see the evidence, go to nobabies.net and check the March 25, 2010 posting. 

The web site has other evidence, other lines of reasoning and correspondence like this if you are interested.  It reminds me of an old Uncle Scrooge comic book in which a chasm was discovered under the money bin.  Bearded scientists were called in to study it.  One remarked, “I dropped my glasses ten minutes ago and they haven’t hit bottom yet.”  I mean this is a really big hole under our present assumptions. 

So when you point out that Spanish colonial rule lasted 300 years I say, “Not surprising.”  When you say that the Spanish conquest took centuries, I think I”t took that long for all the societies they were overrunning to reach the end of their mortal span.”  When you say that the primary Inca producers lived in little hamlets of 10 families I think, “Yes.  That would probably work.”  And at each level up the hierarchy the social horizon was probably also just about 10 families. 

I appreciate the fact that you give due consideration to the question of the impact of epidemic diseases on the natives.  For most people it seems just to be a “gimme.”  They died of infections because they did not have thousands of years of exposure to them.  But that really won’t wash.  It makes sense in the first generation, but after that it is a level playing field.  Everyone gets a chance to be exposed in childhood.  I know of nobody who has seriously proposed that native Americans today have a poor immune system.  (They do have a lot of tuberculosis, but that is probably because of how they live.  And there may indeed be a genetic predisposition to gallstones, but I have never seen that invoked as a historical force.) 

Please let me know what you think.


M. Linton Herbert MD 

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