The Diffusion of Innovations

One kind of uncertainty is generated by an innovation, defined as an idea, practice, or object that is perceived as new by an individual or another unit of adoption. An innovation presents an individual or an organization with a new alternative or alternatives, as well as new means of solving problems. However, the probability that the new idea is superior to previous practice is not initially known with certainty by individual problem solvers. Thus, individuals are motivated to seek further information about the innovation in order to cope with the uncertainty that it creates.

-Everett Rogers, Diffusion of Innovations, 5th Edition.

No one can pretend to a comprehensive understanding of human social systems until they have read the latest edition of Everett Rogers’ Diffusion of Innovations, or familiarized themselves with the literature it surveys by some other means. This is not to say that you will achieve perfect knowledge of such systems upon completing the book, nor would Rogers have made such a claim. What Rogers provides is a sense of how much has been accomplished in the young field he helped to create, and how many unanswered questions still remain.

The Basics

Image from UNODC

Rogers is relentless in his categorization and definition of concepts in the diffusion model, but some basic notions can be spelled out without resorting to his level of detail.

The contribution of the diffusion literature that has itself diffused widely beyond the field is the concept of the early adopter. Rogers lays out several categories of adopter, including a stage before the earlier adopter, which he calls the “innovator”. Counterintuitively, the innovator is not actually the one who comes up with the innovation, but is simply the very first to adopt it. Then comes the early adopters, followed by the early majority, the late majority, and the laggards.

Studies conducted in different disciplines across a broad range of subjects over a course of decades have consistently found that adoption, plotted over time, looks like the S-shaped curve pictured above. The initial adoption period, during which only the innovators and the early adopters are adopting, begins relatively slowly. The middle period, when the early majority and then the late majority adopt, occurs extremely quickly. Finally, the laggards are the last to the party and even after everyone else has adopted their adoption is quite slow.

The part of the diffusion curve from about 10 percent adoption to 20 percent adoption is the heart of the diffusion process. After that point, it is often impossible to stop the further diffusion of a new idea, even if one wished to do so.

Heterogeneity and homogeneity are crucial components of the social system in which innovations spread. Innovators are standalone individuals who are so different from the rest of the people in the social system that their adoption does nothing to encourage other individuals to adopt the innovation. I used to think that Robert Scoble was the quintessential early adopter, but by Rogers’ terminology I think he is actually an innovator. He tries out absolutely everything, often years before anyone else does. The way he uses the innovations he adopts is often very different from how much later adopters will end up using it. I think few people actually adopt something because the Robert Scobles of the world did it first.

On the other hand, early adopters are different enough that they are more likely to adopt an innovation than the majority, but similar enough to the majority that they are much more likely to follow suit eventually.

Early adopters are a more integrated part of the local social system than are innovators. Whereas innovators are cosmopolites, early adopters are localites.

In spite of what many early 20th century communications thinkers believed, mass media has an insignificant effect on our behavior compared to our peers. Once adoption reaches the “majority”–which Rogers claims accounts for about 68 percent of a population–the adoption rate skyrockets, because the early and late majorities are comprised of a large number of highly homogeneous individuals who are looking to one another for cues about whether the innovation is worth the effort of adopting.

The laggards are the last group to adopt, and their rate of adoption remains quite slow relative to the big upsurge in the middle period of diffusion. One interesting thing I had not realized before reading Diffusion of Innovations is that there usually exists a big socioeconomic gap between early adopters and laggards. This makes a certain sense–the downside risk is smaller for a relatively wealthier person taking on the costs of adopting an untested innovation than it is for a relatively poorer one. The difference between the two categories isn’t always one of wealth, though, but the gap usually does exist in some form of social status.

There is much, much more to it than this basic picture. An enormous amount of work has been done studying the various communication channels through which innovations spread, and the social systems that provide the institutions and context the adopters interpret the innovations from, and just about every aspect of the innovation-generation, diffusion, and implementation processes.

The Book and Its Author

Diffusion of Innovations is an interesting book with an interesting history. I don’t know if it’s really accurate to call what I read the 5th edition, as I get the sense that it is so radically different from the first as to be almost an entirely distinct book. The first edition was published in 1962, with the express intention of unifying the research efforts conducted in disparate academic disciplines and providing a common theoretical framework. The 5th edition was published in 2003 and is just as concerned with criticizing and exposing the flaws in what Rogers calls “the classical diffusion model”–the one he himself was instrumental in formalizing!–as it is with introducing the basics to newcomers.

Rare is the scholar who introduces a theoretical model that becomes the foundation for an entire line of academic research. Rarer still is the scholar who is able to see various critiques and contradictions to his model, accept them, and work to improve the model! Rogers was exceptionally open minded and well read. On the latter count, every theoretical concept introduced in the book is immediately followed up with specific case studies to demonstrate what they mean in practice. He was there at the very beginning of diffusion research and has lived to see it evolve.

My only regret where the book is concerned is that it was not written more recently–at the time it was published, Rogers’ most recent source of information on Internet adoption showed that there were a little over 500 million computers connected to it in the world. Today, over 800 million people are active on Facebook alone! From his Wikipedia page I see that Rogers passed away in 2004–this is truly tragic, as I would have loved to read what he thought about what has transpired on the web in the 9 or so years since the 5th edition was published.

Any scholar of human nature who isn’t familiar with this literature owes it to themselves to read this book.

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Adam Gurri

Adam Gurri works in digital advertising and writes for pleasure on his spare time.