In cultural anthropology and cultural geography, cultural diffusion, as conceptualized by Leo Frobenius in his 1897/98 publication Der westafrikanische Kulturkreis, is the spread of cultural items—such as ideas, styles, religions, technologies, languages etc.—between individuals, whether within a single culture or from one culture to another. It is distinct from the diffusion of innovations within a specific culture. Examples of diffusion include the spread of the war chariot and iron smelting in ancient times, and the use of automobiles and Western business suits in the 20th century.
Five major types of cultural diffusion have been defined:
- Expansion diffusion: an innovation or idea that develops in a source area and remains strong there, while also spreading outward to other areas. This can include hierarchical, stimulus, and contagious diffusion.
- Relocation diffusion: an idea or innovation that migrates into new areas, leaving behind its origin or source of the cultural trait.
- Hierarchical diffusion: an idea or innovation that spreads by moving from larger to smaller places, often with little regard to the distance between places, and often influenced by social elites.
- Contagious diffusion: an idea or innovation that spreads based on person-to-person contact within a given population.
- Stimulus diffusion: an idea or innovation that spreads based on its attachment to another concept.
Inter-cultural diffusion can happen in many ways. Migrating populations will carry their culture with them. Ideas can be carried by trans-cultural visitors, such as merchants, explorers, soldiers, diplomats, slaves, and hired artisans. Technology diffusion has often occurred by one society luring skilled scientists or workers by payments or other inducement. Trans-cultural marriages between two neighboring or interspersed cultures have also contributed. Among literate societies, diffusion can occur through letters, books, and, in modern times, through electronic media.
There are three categories of diffusion mechanisms:
- Direct diffusion occurs when two cultures are very close to each other, resulting in intermarriage, trade, and even warfare. An example of direct diffusion is between the United States and Canada, where the people living on the border of these two countries engage in hockey, which started in Canada, and baseball, which is popular in American culture.
- Forced diffusion occurs when one culture subjugates (conquers or enslaves) another culture and forces its own customs on the conquered people. An example would be the forced Christianization of the indigenous peoples of the Americas by the Spanish, French, English and Portuguese, or the forced Islamization of West African peoples by the Fula or of the Nuristanis by the Afghans.
- Indirect diffusion happens when traits are passed from one culture through a middleman to another culture, without the first and final cultures being in direct contact. An example could be the presence of Mexican food in Canada, since a large territory (the United States) lies between.
Direct diffusion was common in ancient times, when small groups of humans lived in adjoining settlements. Indirect diffusion is common in today's world because of the mass media and invention of the Internet. Also of interest is the work of American historian and critic Daniel J. Boorstin in his book The Discoverers, in which he provides an historical perspective on the role of explorers in the diffusion of innovations between civilizations.
The many models that have been proposed for inter-cultural diffusion are:
- Migrationism, the spread of cultural ideas by either gradual or sudden population movements;
- Culture circles diffusionism (Kulturkreise)—the theory that cultures originated from a small number of cultures;
- "Kulturkugel" (a German compound meaning "culture bullet", coined by J. P. Mallory), a mechanism suggested by Mallory to model the scale of invasion vs. gradual migration vs. diffusion. According to this model, local continuity of material culture and social organization is stronger than linguistic continuity, so that cultural contact or limited migration regularly leads to linguistic changes without affecting material culture or social organization.
- Hyperdiffusionism—the theory that all cultures originated from one culture;
- Evolutionary diffusionism—the theory that societies are influenced by others and that all humans share psychological traits that make them equally likely to innovate, resulting in development of similar innovations in isolation.
A concept that has often been mentioned in this regard, which may be framed in the evolutionary diffusionism model, is that of "an idea whose time has come" — whereby a new cultural item appears almost simultaneously and independently in several widely separated places, after certain prerequisite items have diffused across the respective communities. This concept was invoked with regard to the independent development of calculus by Newton and Leibnitz, and the inventions of the airplane and of the electronic computer.
Hyperdiffusionists deny that parallel evolution or independent invention took place to any great extent throughout history; they claim that all major inventions and all cultures can be traced back to a single culture.
Early theories of hyperdiffusionism can be traced to ideas about South America being the origin of mankind. Antonio de León Pinelo, a Spaniard who settled in Bolivia, claimed in his book Paraíso en el Nuevo Mundo that the Garden of Eden and the creation of man had occurred in present-day Bolivia and that the rest of the world was populated by migrations from there. Similar ideas were also held by Emeterio Villamil de Rada; in his book La Lengua de Adán he attempted to prove that Aymara was the original language of mankind and that humanity had originated in Sorata in the Bolivian Andes. The first scientific defence of humanity originating in South America came from the Argentine paleontologist Florentino Ameghino in 1880, who published his research in La antigüedad del hombre en el Plata.
The work of Grafton Elliot Smith fomented a revival of hyperdiffusionism in 1911; he asserted that copper–producing knowledge spread from Egypt to the rest of the world along with megalithic culture. Smith claimed that all major inventions had been made by the ancient Egyptians and were carried to the rest of the world by migrants and voyagers. His views became known as "Egyptocentric-Hyperdiffusionism". William James Perry elaborated on Smith's hypothesis by using ethnographic data. Another hyperdiffusionist was Lord Raglan; in his book How Came Civilization (1939) he wrote that instead of Egypt all culture and civilization had come from Mesopotamia. Hyperdiffusionism after this did not entirely disappear, but it was generally abandoned by mainstream academia.
Diffusion theory has been advanced as an explanation for the "European miracle", the adoption of technological innovation in medieval Europe which by the 17th century culminated in European technological achievement surpassing the Islamic world and China. Such technological import to medieval Europe include gunpowder, clock mechanisms, shipbuilding, paper and the windmill, however, in each of these cases Europeans not only adopted the technologies, but improved the manufacturing scale, inherent technology, and applications to a point clearly surpassing the evolution of the original invention in its country of origin.
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. Heyerdahl's theory of Polynesian origins has not gained acceptance among anthropologists.
Major contributors to inter-cultural diffusion research and theory include:
- Franz Boas
- James Burnett, Lord Monboddo
- Leo Frobenius
- Cyrus H. Gordon
- Fritz Graebner
- A. C. Haddon
- Stephen C. Jett
- Alice Beck Kehoe
- David H. Kelley
- A. L. Kroeber
- E. Lorges
- William James Perry
- Friedrich Ratzel
- W. H. R. Rivers
- Everett Rogers
- Wilhelm Schmidt
- Grafton Elliot Smith
- E. B. Tylor
- Clark Wissler
- Thomas Friedman
- Vinay Joseph
- In the context of Indo-Aryan migration; Mallory, "A European Perspective on Indo-Europeans in Asia". In The Bronze Age and Early Iron Age Peoples of Eastern and Central Asia. Ed. Mair. Washington D.C.: Institute for the Study of Man (1998)
- The term is a 'half-facetious' mechanical analogy, imagining a "bullet" of which the tip is material culture and the "charge" is language and social structure. Upon "intrusion" into a host culture, migrants will "shed" their material culture (the "tip") while possibly still maintaining their "charge" of language and, to a lesser extent, social customs (viz., the effect is a diaspora culture, which depending on the political situation may either form a substratum or a superstratum within the host culture);
- Legend and lore of the Americas before 1492: an encyclopedia of visitors, explorers, and immigrants, Ronald H. Fritze, 1993, p. 70
- Indians of the Andes: Aymaras and Quechuas, Harold Osborne, 2004, pp. 2–3
- The Routledge Dictionary of Anthropologists, Gérald Gaillard, 2004, p. 48
- Megaliths, Myths and Men: An Introduction to Astro-Archaeology, Peter Lancaster Brown, 2000, p. 267
- Sociocultural Evolution: Calculation and Contingency, Bruce G. Trigger, 1998, p. 101
- Carlo M. Cipolla, Before the Industrial revolution: European Society and Economy 1000–1700, W.W. Norton and Co., New York (1980) ISBN 0-393-95115-4
- Peter Jackson: The Mongols and the West, Pearson Longman 2005, p. 315
- Donald F. Lach: Asia in the Making of Europe. 3 volumes, Chicago, Illinois, 1965–93; I:1, pp. 82–83
- Robert Bartlett: The Making of Europe. Conquest, Colonization and Cultural Change 950–1350, Allen Lane, 1993
- Robert C. Suggs The Island Civilizations of Polynesia, New York: New American Library, pp. 212-224
- Kirch, P. (2000). On the Roads to the Wind: An archaeological history of the Pacific Islands before European contact. Berkeley: University of California Press, 2000
- Barnes, S.S.; et al. (2006). "Ancient DNA of the Pacific rat (Rattus exulans) from Rapa Nui (Easter Island)" (PDF). Journal of Archaeological Science. 33 (11): 1536. doi:10.1016/j.jas.2006.02.006.
- Physical and cultural evidence had long suggested that Polynesia was settled from west to east, migration having begun from the Asian mainland, not South America. In the late 1990s, genetic testing found that the mitochondrial DNA of the Polynesians is more similar to people from southeast Asia than to people from South America, showing that their ancestors most likely came from Asia.
- Friedlaender, J.S.; et al. (2008). "The genetic structure of Pacific Islanders". PLoS genetics. 4 (1): e19. doi:10.1371/journal.pgen.0040019. PMC 2211537. PMID 18208337.
- Frobenius, Leo. Der westafrikanische Kulturkreis. Petermanns Mitteilungen 43/44, 1897/98
- Kroeber, Alfred L. (1940). "Stimulus diffusion." American Anthropologist 42(1), Jan.–Mar., pp. 1–20
- Rogers, Everett (1962) Diffusion of innovations. New York: Free Press of Glencoe, Macmillan Company
- Sorenson, John L. & Carl L. Johannessen (2006) "Biological Evidence for Pre-Columbian Transoceanic Voyages." In: Contact and Exchange in the Ancient World. Ed. Victor H. Mair. University of Hawaii Press, pp. 238–297. ISBN 978-0-8248-2884-4; ISBN 0-8248-2884-4
- "Diffusionism and Acculturation" by Gail King and Meghan Wright, Anthropological Theories, M.D. Murphy (ed.), Department of Anthropology, College of Arts and Sciences, The University of Alabama.