Information Cascades That Kicked Off Ancient Empires
The diffusion of new technologies and innovations have defined the history of the human race, and are at the center of much historical research and debate. In particular, innovations in military technology starting approximately 3000 years ago spread from society to society and allowed for the rise of the first ancient empires. This era of innovation included the invention of the bit and bridle that allowed people to control horses, and the spread of iron-working techniques throughout Eurasia that in turn led to the invention of crossbows and catapults. In the article “The Horse Bit and Bridle Kicked Off Ancient Empires: A New Giant Dataset Tracks the Societal Factors that Drove Military Technology,” complexity scientist Peter Turchin and historian Dan Hoyer discuss their work to build and analyze a large database of past societies in order to identify what drove this cascade of technological innovation.
To trace the spread of technology, Turchin and Hoyer broke them down into six dimensions: hand-held weapons, projectiles, armor, fortifications, transport animals, and metallurgical advances. These six were then subdivided even further into a total of 46 variables. From there, they coded whether each historical society at certain points in time possessed these technologies; such as when crossbows were first recorded to appear in China (400 B.C.).
Through statistical analysis, the researchers found that the major drivers of innovation were the overall world population, increasing connectivity among large states, and a few specific technological advances that led to a cascade of other innovations. They discuss a specific example from around 1000 B.C., when nomadic herders in the steppes north of the Black Sea invented the bit and bridle to better control horses, and combined this invention with powerful bows and iron arrowheads. In the words of Turchin and Hoyer, “[h]orse archers became the weapon of mass destruction of the ancient world… Shortly after 1000 B.C., thousands of metal bits suddenly appeared and spread within the Eurasian steppes”.
As connections grew between societies, so did competition. New deadly inventions such as those of the nomadic herders forced other societies to either adopt them as well, or develop their own inventions to level the playing field; farming societies were forced to develop new armor and weapons. In this way, technological innovation diffused and spurred further innovation. Although there are of course many other factors and dynamics at play, this is an example of diffusion through networks, and diffusion through imitation. An individual, or in this case a certain society, chooses to adopt a technology or behavior based on whether or not their neighbors have adopted it. In the case of ancient empires, when one society adopted a new technology, their neighbors, and in turn their neighbors and so on, had to adopt new innovations as well in order to survive, causing a cascade of innovation.