Diffusionism is a distinct theoretical approach in anthropology, and to a lesser extent, in sociology, that arose at the end of the 19th century as a reaction to the early theories of unilinear evolutionism. Diffusionism focuses on similarities of cultural patterns among cultures, hypothesizing that those similarities are the result of a process of diffusion, that is, the spread of cultural patterns from one culture to another. There are three types of diffusion theories: hyper-diffusionism, moderate diffusionism, and cultural circles (areas) approach.

The English anthropologists W. J. Perry and Elliot Smith devised hyper-diffusionism. They held that human culture originated in Egypt and that from about 4000 BC progressively diffused to all other cultures and civilizations all over the earth. This approach is, also, often called the” pan-Egyptian”, “heliolithic”, or “heliocentric” school.

German authors Fritz Graebner, Leo Frobenius, and Wilhelm Schmidt, who were members of the historical school in Germany, identified primeval culture complexes, or culture circles (kulturkreise). Their historicist approach postulated that critical aspects of cultures originated in a small number of geographically isolated societies. They also studied cultural archetypes and patterns in world history. American anthropologist Clark Wissler (1929), in a similar vein, identified, based on empirical evidence,  ten „culture areas“ that were created by cultural diffusion in North and South America and the Caribbean.

American anthropologists Franz Boas, Alfred Kroeber, and Robert Lowie developed a position called moderate diffusionism, that allowed for the coexistence of multiple mechanisms of cultural change and transfer. In addition to diffusion, there are also processes of independent invention, acculturation, and others.

At the same time, French sociologist Gabriel Tarde started studying the diffusion of innovations, not across societies and cultures, but in one society. Although Tarde didn’t use the term diffusion, he examined the role of innovation adopters and the social influence of the spread of innovations. Tarde, in lue of diffusion used the term imitaition. He extended the process of imitation to the whole of society and thus came to methodological individualism which serves as the basis for his macro-social theory. Tarde explains social phenomena by permanent, socially shaped, psychological predispositions. Innovations occur in certain social groups and then spread further through social groups, and then to the whole society. If there were no social barriers, innovation would spread quickly and evenly, but in real situations, there are always barriers. The speed and patterns of the spread of innovation depend on these social circumstances.

Individuals, themselves, are not able to resist this spread, but fall under the influence of social groups with which they are connected by interactions. There is a difference, between rural and urban areas, in the way innovations are spreading. In the city, innovations spread like fashion, and when they reach the countryside, innovations are maintained through imitation, which has the form of a habit. Tarde singles out pride, closeness, and racial and class prejudice as psychological barriers to the spread of innovation. Psychological barriers especially reflect social divisions and inequalities. Political power has a special influence, because individuals imitate those who have more power, and avoid imitating those less powerful than themselves. Social consensus is formed when the attitudes adopted by the elite are extended to the whole society. Once the process of spreading innovation begins, it spreads with geometric progression. The spread of social consensus to the whole society is limited by barriers in communication, as well as in situations in which a large number of people find themselves in a crowd because then people reject the views of the politically more powerful and accept the views of those like them.

Authors: Tarde, Gabriel. Frobenius, Leo; Graebner, Fritz; Schmidt, Wilhelm; Smith, G. Elioth.

Books:

Boas, Franz. The Limitations of the Comparative Method of Anthropology (1896);

Graebner, Fritz.  Methode der ethnologie (1911);

Kroeber, Alfred. ‘‘On the Principle of Order in Civilization as Exemplified by Changes of Fashion.’’ American Anthropologist (1919);

     -     Anthropology (1923);

Lowie, R.H. The History of Ethnological Theory (1937);

Schmidt, W. The Origin and Growth of Religion (1931);

     -     The Culture Historical Method of Ethnology: The Scientific Approach to the Racial Question (1939);

Smith, G. E. The Ancient Egyptians and the origin of civilization (Rev. ed.) (1915);

Smith, G.E., B.Malinowski, H.J.Spindler and A. Goldenweiser. Culture: The Diffusion Controversy (1927);

Tarde. Social Laws - an Outline of Sociology (1899, in French 1898);  

     -     The Laws of Imitation (2013, in French (1890).