Damon Centola is director of the Network Dynamics Group and a Sociology professor at the University of Pennsylvania and has conducted a great deal of research into how networks operate and how ideas and movements are spread. I often read such contemporary books in fields related to sociology, culture, and such despite being skeptical of many academic ideas. Very often, ideas are wrapped up into newish sounding definitions without really offering any original insights.
While Centola does toot his own horn a bit, he does present some compelling arguments for his conclusions. His main point is that commonly held notions about movements spreading “virally” are misguided. On a similar note, he rejects the assumption that the best way to give a new idea traction is to have influencers spread it.
The Strength of Weak Ties
A great deal of Change: How to Make Big Things Happen is devoted to refuting an assumption that has been popular among sociologists since the 1970s, based on research by Mark Granovetter: that weak ties are the most important factor for spreading new ideas, information, and viewpoints. Weak ties, of course, refer to connections between people who aren’t close. Although the idea predates the internet (at least as a widely used network) by several decades, Twitter provides millions of examples of how weak ties work. You see a tweet that you find interesting or amusing and retweet it. If enough people do this, it “goes viral,” spreading exactly like a literal virus. According to Centola, this does work sometimes, but only for certain types of content.
Centola claims that we need to understand a crucial distinction between simple and complex contagions. A simple contagion follows the course of a literal virus, spreading from person to person from one population or community to another. Popular hashtags on Twitter often follow this model, as do viral YouTube videos and other cultural creations.
More complex ideas follow a different pattern. Complex contagions, which often challenge commonly held traditions and biases, are not so easily spread. Simply seeing or hearing about these new ideas won’t necessarily cause anyone to adopt them. For this, Centola claims, people need to be convinced by others close to them.
Bridges Narrow and Wide
A related concept is the distinction between narrow and wide bridges. Simple contagions are spread easily via narrow bridges that reach across long distances or pass through many communities. Narrow bridges are spread via weak ties, meaning between people who don’t know each other well. A narrow bridge might consist of a single person sending another person a link to a photo, article, or video.
Wide bridges, on the other hand, require a greater number of connections and stronger ties. An example would be receiving the same link from 5 people. As Centola points out, redundancy is powerful when it comes to persuading someone to try something new (or consider an alternative point of view).
Centola gives quite a few examples of complex contagions that only spread because wide bridges were present, either deliberately or accidentally built. These include Black Lives Matter, the Arab Spring, the introduction of contraception in Korea, and getting Depression-era farmers in the United States to use hybrid corn. In these and other cases, it wasn’t enough to simply expose people to the new ideas. Even having a very well-connected person in the community (what we now call influencers) isn’t enough. The messages need to be reinforced by redundant messages from people in their own network.
In the case of the U.S. farmers, extensive advertising campaigns did not get the farmers to use the hybrid corn. They would only use it if they saw their neighbors using it, which creates a Catch-22 dilemma. The solution was to create a “social cluster” of farmers who experimented with the new corn. As they saw positive results, the practice began to spread.
In the example of Korea, the problem was that birth control ran counter to traditional values. When the government attempted to popularize contraception, the results were a strange mix of successes and failures. As Centola explains, the same information passed along to people from the same culture, produced markedly different results depending on how networks and social clusters were impacted.
To succeed, the new ideas had to be spread via “wide bridges” – which meant people received redundant messages from people they knew and trusted. If people only heard the message from a single source, it was not effective. A similar situation was recorded in Kenya.
As you read these points, especially when summarized and lacking the details and data supplied in the book, it may sound rather obvious. In fact, it’s related to the online marketing principle of providing social proof of your product. Social proof is usually understood to be testimonials and reviews of customers rather than influencers. However, Centola makes a convincing case that wide bridges and strong ties are fundamental to not only selling products but also spreading social movements and getting people to adopt new ideas and behaviors.
Memes and Viruses
I found it interesting that Centola in Change never mentions Richard Dawkins, who coined the term meme. Dawkins’ definition of a meme is “the cultural equivalent of a gene.” Of course, today the popular definition is far narrower and refers to internet images. The idea of memes is closely related to the notion that ideas and movements spread like viruses, something Centola is undermining in this work.
Influence and Propaganda
I have my own agenda when reviewing books like this for the Cultoid website. I often look at things from a contrarian viewpoint that questions the intentions of policy makers and marketers. In that regard, it’s useful to observe the tactics “they” use to influence people.
On social media, it’s well known that there are all kinds of bots and paid shills who attempt to sway public opinion. Centola relates how movements such as BLM spread on Twitter, not from high profile influencers, but from people in the streets connecting with their own networks and expanding outwards.
You could argue that much of this research is common sense. After all, the whole notion of weak ties being all powerful is a relatively recent theory discovered by social scientists. Many of the book’s points could be simplified into a statement such as “peer pressure is more powerful than what you hear from famous people.”
Centola reveals how influence can easily turn into propaganda when he talks about the Chinese government’s policy of using paid agents on Weibo (the nation’s largest social media site) to distract people from controversial topics. What’s most interesting is how China was completely open about its policy. Even knowing what was happening didn’t lessen its effectiveness as social media users were duly diverted from independent thinking.
All of this is useful to know whether you want to influence people yourself or want to be aware of how you’re being influenced. It’s worth paying attention to how you react when “everyone,” whether in your inner circle or “weak ties” is saying or doing something.