expansionsdiffusion

Expansion diffusion is a pattern of diffusion in which a cultural trait, idea, or innovation spreads outward from a source while maintaining a strong presence at its origin. This contrasts with relocation diffusion, where people move and bring traits to new locations, often leaving the original source weaker.

Within expansion diffusion, several modes describe how spread occurs. Contagious diffusion involves rapid, widespread transfer through close contact or proximity, as seen with fashion trends, memes, or illnesses. Hierarchical diffusion starts in prominent, highly connected places and moves to smaller or less connected areas, often passing through influential individuals, organizations, or urban centers before reaching the periphery. Stimulus diffusion occurs when the underlying principle or idea spreads, but the receiving area adopts a modified or different form rather than reproducing the original trait exactly.

Empirical studies of expansion diffusion focus on how innovations, practices, or cultural elements propagate over time and space. Researchers examine factors such as distance, population density, communication networks, social influence, and economic ties to explain the speed and pattern of spread. The framework helps distinguish whether a phenomenon remains concentrated near its source or expands outward in a measurable way.

Examples commonly cited include the spread of fashion and technology through contagious and hierarchical diffusion, or the diffusion of ideas and institutional reforms through stimulus diffusion. Understanding expansion diffusion provides insight into how cultural landscapes evolve, how trends gain traction across regions, and how local contexts modify incoming traits while the core concept continues to diffuse.