Monday, 14 May 2012

What happened during the neolithic revolution?

Daron Acemoglu and James Robinson write,
The archaeologist Bruce Smith in his book The Emergence of Agriculture describes the transition which took place in the Middle East in the following way (page 79):
their inhabitants had clearly shifted to permanent year-round settlements as early as 12,500 years ago and invested considerable labor in constructing houses and storage facilities.

When people established sedentary settlements, their concepts of who owned resources likely became more restrictive as they strengthened their claim on the surrounding countryside, which they viewed more and more as being for their exclusive use. By 12,5000 BP, then, hunting and gathering societies began to adopt a way of life that set the logistic, economic, and organizational groundwork for the emergence of village farming communities…many of the basic elements of social organization essential to village life were already in place before the first experiments with cultivation…
In other words, the existing evidence, in contrast to what is presumed in Diamond’s argument and the conventional wisdom, is that institutional innovation did not follow transition to agriculture, but preceded it. In fact, it was this institutional innovation which allowed the technological changes at the heart of the Neolithic Revolution.

So most likely, the Neolithic Revolution is also not about geography but all about institutions.
What could lead to sedentary settlements and the related institutional developments? Trade?

Haim Ofek writes,
Modern humans stayed anatomically unchanged at least for the past 80,000 years. On the evolutionary level of organization, anatomically fixed things are expected to stay (nearly) fixed in behavior. Our (anatomically) modern ancestors lived up to this rule for the first half, or slightly more, of their tenure on earth. All hell broke loose in the second. The extraordinary changes in the archaeological record starting around 40,000 to 30,000 years ago, and carrying through the height of the last ice age to the onset of the Holocene (some 10,000 years ago), suggest remarkable refinements in behavioral structures unexpected of a morphologically fixed organism. Changes in the record further suggest a remarkable increase in regional and temporal diversity of material structures that up to that point varied little through time and space. The Middle to Upper Paleolithic transition, or the creative explosion as this episode has sometimes been labeled (e.g., Pfeiffer, 1982), is most vividly evident in wall paintings preserved in caves, in portable art, personal ornamentation, and in elaborate burials. More subtle are the sudden refinements in tools, and the rapid expansion into new geographic areas, indeed, into two new continents (Australia and the Americas). Underlying all ofthis is an authentic economic expansion reminiscent of various mercantile and industrial revolutions in recorded history.

The key question, from an evolutionary viewpoint, is how could such remarkable changes take place in functional behavior without apparent change in morphology. One possible explanation ascribes this turn of events to some neurological change that led to an evolution in behavior without an apparent change in anatomical form (e.g., Klein 1992), Alternatively, it has been argued that on this occasion "culturally organized behavior ... revolutionized our evolution in a way that may have been quite independent of genetic change" (Binford 1992).
Developments in trade and innovations in institutions fall into the second of these two categories.

About trade and innovation Matt Ridley writes,
Without trade, innovation just does not happen. Exchange is to technology as sex is to evolution. It stimulates novelty.
Ridley continues,
If you are not self-sufficient, but are working for other people, too, then it pays you to spend some time and effort to improve your technology and it pays you to specialise. Suppose, for example, that Adam lives in a grassy steppe where there are herds of reindeer in winter, but some days' walk away is a coast, where there are fish in summer. He could spend winter hunting, then migrate to the coast to go fishing. But that way he would not only waste time travelling, and probably run a huge risk crossing the territory of another tribe. He would also have to get good at two quite different things.

If, instead, Adam sticks to hunting and then gives some dried meat and reindeer antlers - ideal for fashioning hooks from - to Oz, a coastal fisherman, in exchange for fish, he has achieved the goal of varying his diet in a less tiring or dangerous way. He has also bought an insurance policy. And Oz would be better off, because he could now catch (and spare) more fish. Next Adam realises that instead of giving Oz raw antlers, he can give him pieces of antler already fashioned into hooks. These are easier to transport and fetch a better price in fish. He got the idea when he once went to the trading point and noticed others selling antlers that had already been cut up into easy segments. One day, Oz asks him to make barbed hooks. And Adam suggests that Oz dries or smokes his fish so it lasts longer. Soon Oz brings shells, too, which Adam buys to make jewellery for a young woman he fancies. After a while, depressed by the low price fetched by hooks of even high quality, Adam hits on the idea of tanning some extra hides and bringing those to the trading point, too. Now he finds he is better at making hides than hooks, so he specialises in hides, giving his antlers to somebody from his own tribe in exchange for his hides. And so on, and on and on.

Fanciful, maybe. And no doubt wrong in all sorts of details. But the point is how easy it is to envisage both opportunities for trade among hunter-gatherers - meat for plants, fish for leather, wood for stone, antler for shells - and how easy it is for Stone Age people to discover mutual gains from trade and then to enhance that effect by further specialising and further dividing labour. The extraordinary thing about exchange is that it breeds: the more of it you do, the more of it you can do. And it calls forth innovation.
Is it too fanciful to think that if Adam and Oz are trading regularly and meeting at a given trading point that someone would not settle down at that point and thus become somewhat more sedentary that before?

Ridley goes on to say,
Moreover, some ancient hunter-gatherer societies reached such a pitch of trade and prosperity as to live in dense, sophisticated hierarchical societies with much specialisation. Where the sea produced a rich bounty, it was possible to achieve a density of the kind that normally requires agriculture to support it - complete With chiefs, priests, merchants and conspicuous consumption. The Kwakiutl Americans, living off the salmon runs of the Pacific North West, had family property rights to streams and fishing spots, had enormous buildings richly decorated with sculptures and textiles, and engaged in bizarre rituals of conspicuous consumption such as the giving of rich copper gifts to each other, or the burning of candlefish oil, just for the prestige of being seen to be philanthropic. They also employed slaves. Yet they were strictly speaking hunter-gatherers. The Chumash of the Californian channel islands, well fed on sea food and seal meat, included specialist craftsmen who fashioned beads from abalone shells to use as currency in a sophisticated and long-range canoe trade. Trade with strangers, and the trust that underpins it, was a very early habit of modern human beings.
Thus trade may be part of the answer as to why we see sedentary settlements and the related institutional developments during the Neolithic Revolution.
  • Ofek, Haim (2001). Second Nature: Economic Origins of Human Evolution, Cambridge: Cambridge University Press.
  • Ridley, Matt (2010). The Rational Optimist: How Prosperity Evolves, New York: Harper.

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