Civilization: diffusion and impact of culture

March 19, 2011 at 12:22 am (Civilization) (, , , , , )

This is part 2 of my Civilization series.

Diffusion and impact of culture

The reality of human interactions is that we fear and avoid what we don’t understand.  Most conscious thought about culture is about differences: “we” have this way of doing things, “they” do something else.  This affects all interactions in a fundamental way.  Similar cultures will mix more, trade more, share more than distant cultures.

But culture is more than a way of being – it affects the way people interact in and behave very deep ways.  Turchin’s theory of civilization says that Asibiya – the ability for group action – builds up exactly on the borders between cultures.  This is because the definition of “us” becomes very clear when contrasted to a very different “them”.  It’s a nasty fact of humanity that people can show great altruism and kindness to others, yet on an everyday level it is often nepotism – aggression towards people out of your group – that rules.  The origin of states arises from small tribes lies that form strong bonds –  which is precisely what Asibiya is designed to explain.

Culture and religion are integrally related, and religion is an aspect of culture that kingdoms have some reasonable control over.  Although switching between Christianity and Muslim faiths has been a long and painful process for many nations, religions can splinter off and yet remain fundamentally the same thing to the peasantry.  Protestantism appeared mostly as a response to Catholic domination and attempts to influence politics. Although almost the same faith, the differences create a strong “us and them” feeling in people – at least the nobles – that allows wars to be justified and alliances forged.  Yet both are “us” when compared to their more different neighbours – Muslims, or the Sikhs, or the Jews.

Differences in religion and culture in general control what is acceptable and unacceptable in war, whether the enemy is just an ally with the wrong king, or an inhuman devil.  What do the populace think of the king burning an enemy city?  If there is little shared culture with the city then people will be content, possibly even happy to see the influx of “free” goods and slaves.  But if people know people of the persecuted culture, trade there, visit there on pilgrimage or have a religious empathy for them, then they will object, strongly.  In ancient times, warfare often resulted in the burning of cities and the taking of slaves.  Conversely, during the late middle ages (and most civil wars) the European nobility fight each other – and people do die – but cities go on much as they always had because nobody would benefit from harming the people.

So how does cultural difference arise?  It seems natural to expect that prehistoric states varied greatly more than we see today – the same is certainly true of African, Papuan, American and other tribal societies, which also support a great deal more genetic diversity.  Culture goes back millions of years, to before our split with he great apes, and has perhaps appeared in limited form in many species. From this very diverse state, culture has “diffused“, so that ideas are shared.  Where some ideas lead to (or are simply associated with) success, they tend to dominate and spread to wide areas.  Because of this association with success, culture often spreads where people spread: farming, metal working, and other highly succesful strategies are clearly visible in the genetic record.

Since culture moves with people, and people do not move homogeneously but in waves, displacing those who have gone before them.  On the front of this wave is always a new technology or way of life, and with it associated a very different way of being from those on the other side of the divide.  Further (more historical) examples are the Roman expansion into the barbarian lands, the American conquest, the formation of Russia and of Australia, and of China (during multiple periods).  These waves do not grow forever, but they do leave cultural borders at which Asibiya can grow due to the added pressures of living in proximity to a strange and dangerous culture.

Living on a cultural border is both a very dangerous, and potentially very rewarding.  Almost all great empires are formed there, and the mixture of cultures allows each to take on a form very distinct from its origins.  Examples abound, and counterexamples are hard to find – Egypt, China, Greece, Rome, the Islamic empire, Russia, Britain, America – all were forged on the borders of the strongest empires of the previous era, and most often on the border at which the largest cultural differences occurred.

Culture is also important as a way of spreading change within established groups, not just in forming nations.  Money, writing, mapmaking, shipbuilding, architecture – all these and more ideas can be exported through the movement of people that use them.  It also shapes how people interact and function in everyday lives.  Successful ideas spread on the back of cultural diffusion, and to take them in, an empire must also import the aspects of culture associated with them.  Just look at how American business – and in parallel it’s culture – exported throughout the world today.

Relation to civilization

This leads to a clear dynamic for culture in civ interactions: the magnitude of trade and other agreements depends on the degree of similarity between the two cultures.  It really is better to be at war with distant heathens than your neighbours because of the lost revenue, and the disapproval of your subjects.

An important dynamic can be that the presence of a very different other on the border will unite people to a degree – they have more motivation to be united.  But the same force can quickly flip to work in reverse – if an empire is very large and unstable, then a  new and dynamic culture may form from the fusion of two very dissimilar ones, rebelling from their host empires and – if initially successful – able to gather momentum at a pace that will lead to their rapid ascension as the new power.

Cultures that interact will be exchanging people, culture and ideas, and will become similar according to how strongly this occurs.  The deliberate adoption of an imported technology will come at the cost of imported culture – a dynamic that enables cultural victory by exporting your nations ideas to the world.  And conversely, the collapse of an empire that has already exported much culture is not so catastrophic because in its ashes lie the shared cultural bonds that will enable the pieces to be picked up, and will find itself in a far more familiar world.

As before, this needs to be implemented as a genuine dynamic that can form part of a player’s strategy.  It will probably correspond to the creation of a new cultural group – the fusion between the two original groups – that can pick and choose the cultural traits that are most suitable for the current times.  In a sense, it is more likely that religion be created from such a succession than a religious movement will cause a succession to happen – the historical examples of Christianity and Islam both indicate that a lot of similar thought was around in the time period.  They both found success by exporting cultural values that were successful.

Essential reading for this section:

*P. Turchin: “Historical Dynamics :Why states rise and fall” (2003) (this is needed for all sections…)

Hamon & Loh 2010: “The Index of Cultural Diversity A New Quantitative Measure of Trends in the Status of the World’s Languages”.  Language Documentation & Conservation.

Battaglia et al 2009: “Y-chromosomal evidence of the cultural diffusion of agriculture in southeast Europe”.  European Journal of Human Genetics (2009) 17, 820–830.

Wen et al 2004: “Genetic evidence supports demic diffusion of Han culture”.  Nature 431, 302-305 (2004).

Byrne 2007: “Culture in great apes: using intricate complexity in feeding skills to trace the evolutionary origin of human technical prowess”. PRSB.

This series:

Back to “rise and fall”

Civilization index


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Rise and Fall of Civilization: Index

March 3, 2011 at 12:18 am (Civilization) (, , , , , , , , , )

I need to make two confessions.  Firstly, in my “youth” I have been just a little addicted to the “Sid Meier’s Civilization” series of games.  Secondly, I have since been thinking very deeply about history – deep enough that I have supervised a Master’s Project studying the processes that allow civilisations to rise, and fall.  Over the next few weeks, I’m going to write several posts distilling my thoughts, with each split into:

  1. Some aspect of history that has an interesting and dynamic pattern;
  2. How this might relate to “simulations of history”, i.e. civilization.  This part of the post will mostly only be of interest for those also needing a visit to Civilization Anonymous (after just one more turn!).

This is an introduction and index; I will update each topic below with the correct link when they are published.  The posts will start out well researched with academic references at the bottom and web links in the text; towards the end of the series my “expert knowledge” will wane.


It has been claimed that history is just “one damn thing after another“.  Certainly history is extremely complex, and there are almost  no examples where there is a simple cause and effect for large-scale events.  But that does not mean that there are no patterns to be found.  Broad generalisations about the human psyche are possible when modern experimental psychology, sociology, and human geography are combined with game theory, mathematical modelling* and computer simulation.  Resting only on the assumption that people everywhere, at all times, were just people – with the same set of biological drives –  we can hope to apply the full scientific method to the study of history.  Combined with quantified historical and archeological evidence, there is the glimmering of a new renaissance in the study of history.

Across the intellectual divide,  Civilization 4 (with some modifications) is the most complete simulation we have for the processes that have shaped history.  Although its remit is to be “just” a game, by exploring how the game unfolds we might learn something about how history itself could have unfolded. And we learn that we don’t understand all of the rules it followed.  It is of great interest to understand a simulation model for the world that replays history as accurately as we can manage, without having to add too many of the specifics ourselves.

I first discussed these ideas when I decided to take the plunge and do some real research on the subject.  Although I will link a lot to Wikipedia, most of the ideas are fully fleshed out in the references at the bottom.


  1. Rise and fall
  2. Diffusion of Impact and Culture

Essential reading for this section

A. Toynbee: “A Study of History (1961).

*P. Turchin: “Historical Dynamics :Why states rise and fall” (2003) (A must read!)

E. Rasmusen: “Games and Information: An Introduction to Game Theory” (2009). (or similar)

Fotheringham et al. “Quantitative geography: perspectives on spatial data analysis” (2000).  (or similar)

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Thinking through games.

January 4, 2009 at 11:57 pm (Articles, science) (, , , , )

Most games are idle distraction from reality. However, sometimes we can learn things from them. I think I’ve uncovered something very important playing Civilisation 4.

How, you might well ask? In the game, you control a civilisation from its origin through to the colonisation of another planet. Your civilisation grows from a small band of farmers to a world spanning empire. And here is the thing: it only ever gets bigger and better.

Can you think of another empire throughout history for which this is true? There isn’t one. The ancient Mesopotamian empires were very short lived. The Greeks were culturally powerful but soon lost their influence. The Romans controlled the basin of the modern world and an unmatched army yet fell within a few hundred years of their empire being established. China failed to capitalise on its huge cultural, scientific and organisational lead in the European dark ages, was repeatedly overtaken by barbarians, and later dominated by European merchants. Simply put: in history the powerful have always failed to keep their power.

Why is this – what is missing from the game? Civilisation is designed to be fun, not realistic – perhaps it misses out some key scientific knowledge. After a years worth of scientific reading, I can conclusively say – nobody knows! I find this shocking, and exciting. There is huge potential here for research – about a fundamental process that has shaped our world as much as religion, and will determine our future.

I don’t mean to say there is nothing known. There are several good books on the subject – “Historical Dynamics: Why States Rise and Fall” by Peter Turchin is a good place to start, as is “Guns, Germs and Steel” by Jared Diamond. There are three basic explanations offered:

  1. Internal economics. As a state gets powerful, it develops various methods for doing things. These might be successful initially but eventually they cause problems, and the society can’t change as fast as some other, weaker societies. Essentially: a strong society causes problems that bring about its decline.
  2. External events, such as barbarians and other empires.
  3. Environmental change. This can be either caused by the society (so is really internally caused) or natural changes such as mini ice-ages (and thus an external event).

Clearly, external events aren’t enough on their own to explain why a big empire falls, because bigger societies have more resources available to cope with the event than smaller ones. So there must be some internal explanation, and there is little agreement about how different societies cope with things so differently.

I’ll make another blog post another time to describe some things that cause societies to become weaker, and whether they mean dramatic changes for the future of our society. But in the current knowledge there is:

  • No causal understanding of what leads to societies weakening, nor when. (1)
  • No accepted way to interpret the evidence to support or reject explanations.

What does this mean, in terms of computer games? It means there are good set of ideas of how societies might get weaker, but no knowledge of how “game rules” can be made from these. And nobody really knows which rules influenced the decline of specific empires in history.

Both of the issues could be addressed through a mathematical framework for societal change (which the game of Civilisation actually is!). So, to get a more realistic game of civilisation, we need to do some fundamental research – maybe Firaxis Games will pay my wages?

Note (1): Turchin’s book is actually the first to try to address this by using mathematical models, but he focusses more on larger scale issues such as european versus eastern influence (which he calls “World Systems”). This sort of modelling is the only way to establish that a given mechanism is really causal of society weakening, and under which conditions.

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