Trans-cultural Diffusion - Disputes

Disputes

While the concept of diffusion is well accepted in general, conjectures about the existence or the extent of diffusion in some specific contexts have been hotly disputed. An example of such disputes is the proposal by Thor Heyerdahl that similarities between the culture of Polynesia and the pre-Columbian civilizations of the Andes are due to diffusion from the latter to the former—a theory that currently has few supporters among professional anthropologists.

Attempts to explain similarities between two cultures by diffusion are often criticized for being ethnocentric, since they imply that the supposed "receptors" would not be capable of innovation. In fact, some authors made such claims explicitly—for example, to argue for pre-Columbian trans-oceanic contact as the "only possible explanation" for the origin of the great civilizations in the Andes and of Central America.

Those disputed are fueled in part by the overuse of cultural diffusion, starting in the late 19th century, as a blanket explanation for all similarities between widely dispersed cultures. The most famous proponent of this theory was Grafton Elliot Smith, who argued that civilization first formed in Ancient Egypt and then diffused to other places.

Diffusion theories also suffer from being inherently speculative and hard to prove or disprove; especially for relatively simple cultural items like "pyramid-shaped buildings", "solar deity", "row of standing stones", or "animal paintings in caves". After all, the act of diffusion proper is a purely mental (or at most verbal) phenomenon, that leaves no archaeological trace. Therefore, diffusion can be deduced with some certainty only when the similarities involve a relatively complex and partly arbitrary collection of items—such as a writing system, a complex myth, or a pantheon of several gods.

Another criticism that has been leveled at many diffusion proposals is the failure to explain why certain items were not diffused. For example, attempts to "explain" the New World civilizations by diffusion from Europe or Egypt should explain why basic concepts like wheeled vehicles or the potter's wheel did not cross the ocean, while writing and stone pyramids did.