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Chapter 1: What is Civilization?

Civilization is one of those terms that have gone into disfavor recently.  There are a few good reasons for that.  The underlying concept is rather abstract, it’s tricky to define precisely, and it’s been used as a prop for politically-minded propagandists for thousands of years.  So, the temptation, in this postmodern age, is to recoil from the term as old-fashioned and unnecessarily judgmental.  Society X wasn’t “less civilized” than society Y, they were just “differently civilized”.  Or, even better, the entire concept privileges some dominant narrative, which proves that the user of the term is incorrigibly racist, sexist, ageist, time-ist, or whatever X-ist is the flavor of the week in academic circles.

As the reader may be able to tell, I find these sorts of political debates tiresome in the extreme.  And, for my purposes, I believe that the concept of civilization is referring to something real and important.  I need it in order to make progress toward resolving my conundrum.  Therefore, for the purposes of this essay, I define civilization as follows:

Civilization (n.): A set of social structures that, taken together, makes it possible for people to live persistently in functional cities.

I like to consider this the “video game” definition of civilization, after Sid Meier’s popular series of games by the same name, since it’s entirely instrumental.  Civilization, here, can be measured by somewhat objective, cross-cultural metrics (such as city size and polity size) with some confidence, much like what you’d see in the video game if you pull up the civilization comparison screen.

Starting with this definition, let’s see what it implies by first investigating the archaeological evidence of the Neolithic Era.  The Neolithic (est. 10,000 BC – 4,000 BC) is when the first cities were built in the Middle East, and examining them gives some clues as to the base, inviolable requirements that are needed in order to support city life.

Minimally, in order to have a city worthy of the name, you need to have a collection of stationary dwellings that are occupied continuously for a long period of time.  This means that, first and foremost, the food problem must be solved.  Traditional hunter-gathering is almost always insufficient for this purpose.  A dense, stationary population of humans tends to drive out calorie-rich prey animals relatively quickly, forcing the remaining gathering efforts to grow more and more intensive to make up for picking the previous rounds of literal low-hanging fruit.  Foragers generally solve this problem by following the food when the pickings become slim, but our requirement for permanent settlement rules that out.

At the technological level of the people who built the first cities, there are only two ways around the problem.  One option is to build the city up around harvesting the bounty of the sea.  Permanent, exclusive fishing settlements can thrive on the right bodies of water, but the fishing effort must be steady, systematic, and not exceed the carrying capacity of the underlying fish population in order to support a permanent settlement.  An excellent example of this pattern is the indigenous people of the Pacific Northwest, who were able to support a substantial population largely on the strength of the vast runs of salmon in their rivers.[1]

The more common solution is agriculture, largely because it scales better than the other approach.  Suitable farmland is much more readily available than dense fisheries.  With Neolithic agricultural techniques and good land, it is possible to yield a significant energy surplus.  A yield of 800 kg of wheat per year is a fairly conservative estimate of what one adult farmer could manage using this technology.  That’s 2.4 million kCal, which is enough to feed the farmer himself and at least two others for a whole year.[2]

But it’s almost impossible to overstate how arduous this process is, both physically and psychologically.  For a couple thousand years, before the invention of the plow or the domestication of draft animals, Neolithic farmers had to use sticks or hoes to disturb the ground and plant their seeds.  Then they had to carefully watch over the growing plants, ensuring that no other plants interfered with the months-long growing process, all the while hoping that circumstances beyond their control (such as weather fluctuations or plant diseases) didn’t bring all their hard work to ruin.

Next, when studying the evidence of the Neolithic, we see that cities of the era could house a thousand or more people.[3]  This is notable because humans don’t naturally congregate into groupings of that size.  It’s worth taking a moment to talk about why that is, and why cities exceeding that size imply something interesting is going on.

Physical anthropologists have reported that the size of primate tribes is correlated with individual brain size.  In the wild, it has been observed that when primate groups grow much beyond this Dunbar limit[4], they tend to split apart.  Given that tribe effectiveness in most activities appears to scale well, assuming sufficient accessible energy density in the environment, this implies that primate sociality is cognitively expensive.  In other words, the typical member of a primate group is likely spending most of his brainpower on maintaining the social fabric of his tribe (naively estimated as a complete graph traversal, which is an O(N^2) operation) and when this problem is no longer routinely solvable, the tribe can no longer function effectively.

The human Dunbar limit has been estimated to be between 100 and 250, with a number of 150 commonly offered up as the best estimate.  This number appears to coincide with the largest sizes of cohesive human tribes, such as nomadic hunter-gatherers and key military groupings (such as the ancient Roman maniple[5] and the modern company[6]).  For my purposes, the exact value of the Dunbar limit shouldn’t be terribly important.  But it is important to recognize that people have trouble forming intense bonds with groups over this number.  Therefore, any social structure that needs to scale past this point will necessarily have different characteristics than one that does not need to so scale.

In practice, for a particular person, I’ll refer to the set of people whose relationships are being mapped using this built-in human social hardware as in that person’s “Monkeysphere”, after a most excellent article written by David Wong:  If you have not encountered it before, I highly recommend you read the entire thing before continuing, as it will turn out to be something of a foundational text for this essay.

Finally, agriculture and sessile settlement implies that control over territory is more crucial for a civilized society.  The game theory behind this statement isn’t too difficult, so let’s try to establish it somewhat formally by walking through the scenario in more detail.

As a simplifying assumption, let’s claim that when two sides fight, the winner is the one that is willing to expend more energy (which is an abstraction over a willingness to risk more injuries, lives, etc., but that should sum up over time).  Let tribe “A” be the attackers and tribe “D” be the defenders.  Then, treating A’s energy expenditure as an independent variable unknown to D at the time of selecting D’s investment, let’s analyze what makes sense for D.

On the one hand, if D is a group of foragers, winning a battle to retain control of their territory means that they get to enjoy the fruits of the land for the next time period.  If they lose, then presumably they are forced to more marginal land, and are penalized the difference between the yields.

If D is a group of farmers, on the other hand, winning the same battle means that they preserve their current investment in the land.  They get to reap what they’ve sown.  Losing, on the other hand, probably means that they’re thrown back on foraging on marginal land, at an additional penalty since they’re not optimized for foraging.

For both groups, the maximum economically rational energy to spend defending is the difference between the “win” yield and the “lose” yield, since at that point your tribe is indifferent between winning and losing.  The asymmetry here comes largely from the fact that winning is so much more valuable to farmers than it is to foragers.  From an energy perspective, a harvest is a huge deal.  Therefore, since the opportunity cost is so much higher, farmers are rationally willing to fight much harder to defend their ground than foragers are.

However, there’s obviously no guarantee that individual people will act in accordance with what makes sense for the group as a whole.  That’s where our discussion of civilization comes in.  Social structures that get people to act in a way that’s more economically rational than their rivals – in this case, fight harder than seems justified naturally – yield better results that lead to propagation throughout time.  Group selection has proven to be a very weak force for genetic change on the individual level, but at a higher level of abstraction, it serves as a pretty good indicator for what sorts of groups (e.g. civilizations) tend to propagate themselves into the next generation.

That’s a lot of claims, which appear to be only somewhat connected!  But, to summarize, civilization as I’ve defined it must at least consist of a social structure that fosters the following three complex behaviors.  Note that none of them arise naturally from stock evolved human (forager) behavior.

  1. Agriculture, which demands much harder work at longer time horizons.
  2. Large City Size, which demands regular interaction with people outside one’s Monkeysphere.
  3. War for Territory, which demands a greater willingness to fight.

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