Diffusion in the literal sense denotes a sense of transmission and dilution. In the Anthropological context, it is the transmission and modification of behaviour among the human population. The theoretical use of diffusion to study culture and cultural diversity is Diffusionism. Generally, these theories differ in the degree of importance assigned to Invention, Innovation and Duplication of behaviour.

Origin of Diffusionism

Early studies in cultural anthropology believed in the Psychic unity of humanity. All civilizations should follow the same developmental trajectory since all humans share the same psychological and biological components. The uni-lineal socio-cultural evolutionary studies sought to classify cultures based on the stage of their development with  Western European society considered the end product. This came to be known as evolutionism. Thus, the Evolutionary school saw invention as the supreme goal for cultural evolution, and it was only a matter of time before all cultures reached their pinnacle.

In contrast, Diffusionism opined that duplication of behaviour would have been much more accessible than independent invention. Therefore different cultures will not have the same developmental trajectory. The introduction of repetition and innovation further meant that communities could selectively choose behaviour that better suited their environment. Diffusionism rejected cultural hierarchy as considered by evolutionism. They instead advocated for cultural relativism. Cultural Relativism argued that ideas, customs, practices and technology are best studied from the culture where they are found.

Schools of Diffusionism

The Diffusionists disagreed on the importance of Invention and Duplication in the context of cultural development. Three schools of thought can be identified.

British School of Diffusionism

• W. J. Perry, G. E. Smith and, to a certain extent, W. H. R. Rivers are considered the pioneers
• Maintained that humans are inherently unimaginative and uninventive. The  Invention of behaviour was an extreme exception rather than a general norm and could be facilitated only in the right conditions
• Duplication of cultural traits through migration and colonisation is how culture was diffused across the population
• All cultures can be traced to a single invention point which G.E Smith identified as the Egyptian civilisation
• It is the most extreme form of diffusionism and is also known as hyper diffusionism
• It did not hold for long because of its fundamental incapability to independent invention and innovation

German School of Diffusionism

• Major proponents include Fritz Graebner and Wilhelm Schmidt
• Rather than a single innovation centre, this school calls for a limited number of centres through which cultural traits are diffused over time and space
• Also maintained that invention and innovation are an exception, and duplication is the norm
• Invention occurred in limited culture centres and diffused outwards. The diffusion of cultural traits is not isolated but occurs as a complete transmission of culture due to migration and contact
• A cultural circle or Kulturkreis (german for culture circle or translated as a cultural field) can be made based on similar cultures. Hence, these cultural centres can be identified. In doing so, the entire cultural history can be discovered
• Lack of empirical success in identifying culture centres and its inability to explain independent inventions contributed to its demise. Furthermore, there is no explanation of the reason for diffusion

American School of Diffusionism

• Franz Boas and Clark Wissler proposed the key features
• Boas argued that culture has its unique history with traits duplicated and modified to suit the culture’s need that borrows it from the other. The origin of the quality might become obscure. Thus Cultures should be studied from the perspective of those who follow the same.
• Duplication and modification are both paramount to the study of culture
• Wissler identified culture areas as regions that have a relatively homogenous culture. Wissler argued that barriers to cultural spread are environmental and physical.  Moreover, societies adopt cultural traits based on their geographical environment
• By considering diffusion as an active interplay of duplication and innovation, the American school of thought surmounted both the criticisms of the earlier schools. It also rationalised diffusion as a means to socio-economic upliftment
• However, The American School of diffusionism is criticised as being too localised and constrictive to the study of global dynamics of culture. Also, what constitutes the boundary of a cultural area is open to debate

Types Of Diffusion

• Expansion diffusion: Cultural traits are spread while remaining strong at the point of their origin point. Examples include the spread of jeans made of denim cloth that is now popular across continents while still prevalent in the USA

• Relocation diffusion: Culture that is now located in a geographical area that was different from where they originated. The Parsi culture and the Parsi community are predominantly thriving in India, while their ancestors came from modern-day Iran

• Hierarchical diffusion: The top-down spread of culture occurs when a small but important group of people adopts a cultural feature and spreads it throughout society. The adoption of the English language by Indian elites led English to be the primary language on the Indian subcontinent

• Contagious diffusion: The spread of traits through direct contact between peoples of different cultures without regard to hierarchy.The modern phenomenon of viral challenges on social media platforms

• Stimulus diffusion: The cultural traits that are heavily modified from as compared to they were at the time of their origin. The features at the source may or may not be similar. The Talent shows organised in different countries have the same concept but are vastly different in their content and relatability

• Maladaptive Diffusion: These are those ideas that may not be well suited to the population that adopts them, yet these are endeared. Modern farming has made meat a staple diet in many countries with rich vegetation

Conclusion  

The advent of diffusionism as a reaction to the evolutionist study of culture has a defining influence on cultural anthropology. Diffusionism gave credibility to the idea of cultural relativism and inspired new tools to the empirical study of culture. The British School of Diffusionism solely focused on duplication, while the German School incorporated the invention of behaviour to a minimal degree.

The American School of Diffusionism represented a holistic view and used Invention, Innovation and duplication to varying degrees. However, Diffusionism on its own could not explain the stratification of culture. While the British School was considered too general, the American School seemed too local. Furthermore, the impact on existing cultural traits after new the introduction of new traits was not discussed. Thus towards the start of the 20th century, anthropologists turned their attention to Acculturation which is the study of how cultures change when they encounter alien civilisations.