Networks, Influence, and Diffusion
The distribution and transmission of culture and social systems across geographic areas, times, and generations are arguably the main engines of civilization. Culture’s “spread in area is generally called diffusion” whereas “internal handing on through time is called tradition” (Kroeber 1948, 411). We have evolved from hunting and gathering with primitive stone tools to our present high-tech society; from social systems based on small kin groups to national governments and international global systems. In the process, we have transmitted what we have learned—both the good and the bad—to the next generation through formal and informal systems. We have also spread disease through biological and social means. Networks are involved in all these transmissions. At a basic, subjective social level something may be transmitted or diffused through (1) contact that involves some form of influence, persuasion, or coercion—for example, someone teaches me something or influences me to do something, to think a certain way, or provide me with a new tool; (2) contact that involves some kind of emulation—e.g., my friend has an idea or a tool that I think it would be useful to have; or (3) adoption or emulation without direct social contact—for example, I hear or read about something that I like. These situations all involve a decision or an action on the part of the recipient of the transmission.
The diffusion of agriculture into Europe about 10,000 years ago could have occurred through the migration of a population that had already adopted the innovation, termed demic diffusion or through presumed imitation or adoption of what must have been