Diffusionism

Diffusionism is the theory about the development of cultures and technologies, particularly in ancient history. The theory holds that a given innovation will have been initiated within a specific culture, but that it would then 'diffuse' by various means from this starting point. Thus a major innovation such as the invention of the wheel would be assumed to have been made in a particular time and place and then to have been passed on to nearby peoples through emulation, trade, military conquest or other means. The innovation thus slowly radiates out from its starting point. The theory may apply to artistic motifs, religious beliefs or indeed any aspect of human culture.

This method has been used to trace back innovations to presumed starting points, and thus to locate their origin within distinct cultures and map the history of their spread. However diffusionism is a problematic theory for various reasons. It is difficult to demonstrate that an innovation must have had a single starting point. Many inventions and cultural ideas may well have been discovered or have evolved independently from one another. Adaptations to human and social needs might easily take similar forms in diverse cultures, if these are the best availible solutions to similar problems. For example pyramids appear in Egypt and Meso-America. But despite the efforts to prove otherwise by diffusionists such as Thor Heyerdahl, the evidence is that they developed quite separately.

Nevertheless cultural and technological diffusion is an undoubted fact of both ancient and modern history. The diffusion hypothesis is often the best model to explain and link archaeological data.