Diffusion of Innovation

Diffusion of innovation is the process through which new ideas, practices, and technologies spread through a population or social system over time via communication channels. Everett Rogers’s Diffusion of Innovations synthesized earlier research and described adopter categories, including innovators, early adopters, the early and late majority, and laggards, as well as the characteristics that affect adoption, such as relative advantage, compatibility, complexity, trialability, and observability. Gabriel Tarde’s laws of imitation anticipated the field, and Bryce Ryan and Neal Gross’s study of hybrid corn adoption among Iowa farmers became a classic. Paul Lazarsfeld and Elihu Katz’s work on personal influence and the two-step flow of communication highlighted the role of opinion leaders, while James Coleman, Elihu Katz, and Herbert Menzel studied the spread of a new drug among physicians through social networks. Mark Granovetter’s strength of weak ties and Thomas Valente’s network models explain how structure shapes diffusion. William Ogburn examined the cumulative nature of invention. Critics note that the model has a pro-innovation bias and can overlook inequality in access. Diffusion of innovation remains central to research on technology, health, marketing, development, and social change.