It is the transmission of elements from one culture to another. Such elements are transmitted by agents using identifiable media and are subject to different barrier or filter effects. It is one of the processes of acculturation but may lack the close contact between peoples that acculturation presupposes. As a theoretical alternative to nineteenth century evolutionism, diffusionism stressed borrowing rather than internal development and identified centers of creations and secondary recipients, was consistent with the comparative spirit. From this view, cultural similarities are prioritized by ethnocentric attitudes concerning advancements and thus accordingly are stigmatized. The readily available patterns of culture dictated by diffusionist theory created the concept of the cultural area, whereby each cultural area would be comprised of essential traits of that particular area. This process of compiling vast amounts of data resulted in the ability to compare and contrast traits among various cultures.
Diffusionism refers to any learned hypothesis that posits an exogenous origin for most elements of a specific culture or cultural subset. An example is the proposition advanced by some nineteenth-century folklorists that most popular European story frames had been transmitted to Europe by Gypsies from India. The notion, however, that cultural evolutionists of the nineteenth century denied the significance of diffusion is not correct. Robert LOWIE in particular overemphasized the association of diffusion and historicism, independent invention, and evolutionism (Harris 1968: 173 6). The fallacy here is that evolutionists promoted independent invention not to defeat diffusionism but to demonstrate the Psychic Unity of Mankind.
Stimulus diffusion is a concept elaborated by A. L. KROEBER to describe the reinvention of an element transmitted across a social or cultural barrier to bring it into congruence with the values of the recipient culture. Popular diffusionism is the attribution, typically false or distorted, of certain cultural elements to foreign cultures, especially antecedent ones, such as the attribution by contemporary Europeans of anything old-looking to the Romans or Celts.
Recent diffusion research in anthropology, sociology, and geography has focused on the pattern of diffusion, producing convergent results. As far back as the end of the nineteenth century, Gabriel de Tarde (1903) noted that the rate at which innovations are adopted tends to follow an S-shaped curve. The curve is now conventionally divided into discrete phases associated with adopter categories (innovators, early adopters, early majority, late majority, and laggards), which have been used as ideal types to explain a range of behaviors with respect to innovation.