CHIBE Q&A: Damon Centola, PhD

Damon Centola, PhD, is Professor of Communication, Sociology and Engineering at the University of Pennsylvania, where he directs the Network Dynamics Group. Dr. Centola is also a Senior Fellow at LDI and affiliated faculty member with the Center for Health Incentives & Behavioral Economics (CHIBE). He just published a book called Change: How to Make Big Things Happen, which you can learn more about on his website. Learn more about Dr. Centola in our Q&A below.

What made you want to write Change: How to Make Big Things Happen?

I am a sociologist who studies the way that beliefs and new ideas and movements spread through our networks and our society. The last decade in the science of networks has been very exciting. New data has allowed us to see how change actually spreads. These new insights into social change overturn many of our existing beliefs about what makes change happen. I wrote this book to share these breakthroughs with everyone. And, to share this new way of understanding the social change unfolding all around us, and hopefully to help people to create the change they want to see.

Can you share one or two strategies for building an infrastructure that promotes change or the spread of new ideas?

One of the key network strategies for building an infrastructure to spread change is to reduce centralization. In my book, I show why ideas and beliefs that reinforce existing biases spread easily in centralized networks, and why innovative ideas that challenge our biases and improve our thinking benefit from egalitarian networks in which everyone has an equal voice. Egalitarian networks allow new ideas and opinions to emerge from anywhere in the community and spread to everyone without being blocked by a powerful social star at the center of the network.

Your book talks about how new behaviors and ideas do not spread like a virus; changes in behavior actually follow certain rules. Could you tell us a bit more about this?

The myth of virality is that everything spreads like a virus. The main thing about a virus, particularly a highly infectious one like the novel coronavirus, is that it may only require contact with a single infected person to transmit it. You don’t even need to know or remember that person in order to for them to transmit the disease to you. This is why COVID-19 is so scary.

A single infected person with lots of random contacts can spread COVID-19 to lots of people. In epidemiology, highly connected people like this are known as “super spreaders” because, left unchecked, they can spread the disease far and wide.

But, behavior change is different. Behavior change is not like a virus, spreading through casual contact. In my book, I show how change does in fact follow rules – and you’ll see how these rules explain the worldwide expansion of new movements like Black Lives Matter. But, learning these rules takes us far beyond the spread of diseases, to reveal a process that is deeper, more mysterious – and much more interesting.

Here is an example: One of the key discoveries that I’ve made in my research is that there are two things about social networks that enable a new behavior to expand from a few early supporters, to the vast majority of a population: The first one, is that one contact is rarely enough.  Social confirmation from multiple peers is typically required, which helps to establish the credibility and legitimacy of a new idea.

The second thing that matters is people receive confirmation from relevant peers. Relevance means that it’s not just how much social confirmation you get for an idea, but also who that confirmation comes from.

This seems simple enough.  Most of us understand that when you’re trying to decide whether an innovative idea or product is right for you, you look to see what people like you are doing. For example, if you’re deciding on a political candidate, you tend to look to people who have similar values as you to see what they will do.

This is also true for fitness programs. People tend to be more influenced by peers who are like them – even if they are overweight – than the fitness icons whose bodies they’re supposed to be emulating.

It’s even true for a board of directors deciding whether or not to adopt a new corporate governance strategy – these people look to their peers at similar institutions to see what strategies they’re adopting.

Surprisingly, it’s even true when we consider taking advice from physicians. Physically fit physicians who lecture their obese patients about the merits of exercise tend to stir up feelings of resentment rather than aspiration. The same thing happens with pediatricians. When pediatricians give advice to parents about vaccination, they are often more effective if they give their advice as fellow parents, rather than as medical experts.

Similarity can often be quite effective for creating relevance. But it’s not always effective.

Sometimes, in fact, the key to relevance is not similarity but diversity. That’s surprising at first, but it makes sense once you realize that sometimes people’s resistance to a new idea is not because they are evaluating whether it’s right for them personally, but because they’re worried about whether it will be perceived as socially acceptable.

A great example of this is the movement to support same-sex marriage. In 2013, the US Supreme Court was hearing two cases that would decide the fate of same-sex marriage. In the weeks leading up to the Supreme Court’s decision, a nonprofit organization initiated a Facebook campaign to encourage citizens to show support for marriage equality by changing their Facebook profiles to a red and pink “equals sign.”

It was stunningly effective. Within a week, nearly 3 million people had joined the campaign. In fact, it’s the most successful campaign in Facebook’s history. The key to its enormous success was people receiving social reinforcement from relevant contacts. But shockingly, the most relevant contacts were not people who were similar to the potential adopters, but rather who were different from them.

The reason for this is that showing support for same-sex marriage was a socially risky thing to do.

On Facebook in 2013, people were connected to their grandparents, their neighbors, their college friends, their colleagues, and their children’s soccer coaches. Everyone was connected to a wide range of social contacts, many of whom had political and social commitments that might differ from their own.

Showing strong support for same-sex marriage was a risky thing to do. It could start an argument on your Facebook page, or create the opportunity for uncivil or even offensive commentary from friends and acquaintances. So, given these challenges, how did the campaign spread so effectively?

The answer is that people typically waited to adopt until they saw several people adopt who were different from themselves, and different from each other. This is because diversity among adopters signaled that the campaign had broad legitimacy.

For example, if people saw that their grandparents had adopted, and also that their colleagues at work had adopted, too, and that even their child’s soccer coach had adopted, then the differences among these adopters was enough to convince them that the movement was widely accepted. This did two things. It not only reduced the social risk of adopting, but also encouraged people to want to be part of the movement that everyone was supporting.

This means that if you want to use the principle of relevance to spread change, you have to know what kind of social proof people are looking for.

If people are looking for confirmation that an innovation is right them – like a fitness routine – then similarity is the key to establishing relevance. But, if they’re looking for confirmation that an innovation is widely accepted and socially legitimate, then diversity is the best way to create social relevance.

The spread of COVID-19 does not require social reinforcement from relevant people. Those factors are irrelevant for the spread of the disease. However, they are important for spreading new behaviors (like wearing facemasks and getting vaccinated) that can prevent COVID-19 from infecting more people. We’ve all seen how face masks and vaccination efforts have not spread nearly as effectively as the disease itself. The myth of virality is a dangerous sand trap for disease prevention efforts during the pandemic. There are, in fact, strategies that we can use to help promote vaccination and face-mask-wearing.  But, they are based on different rules than the ones that viruses follow.