Q: Is there an issue that has shaped all of your work?
I am a network scientist. When I look at the world, I see patterns of social interaction and social networks. I’ve spent the first two decades of my career documenting social epidemics using advanced, computational analytics.
Contagion processes—infectious diseases, for example—are often modeled through social networks. I study phenomena that spread not through a biological mechanism but through social contagion.
Whether it’s the rapid increase in autism cases, mental health medication use, or opioid use disorder, these phenomena, despite having radically different contexts, exhibit very similar patterns—a rapid increase in cases and a huge amount of geographic variation. Those two things are the signature of social epidemics. My work has been trying to understand how these rapid increases arise from individual-level behavior.
Q: How did you decide to become a network scholar?
I think we study and teach what we need. At many points in my life, I have struggled with social anxiety and social interaction. Growing up, I felt like I didn’t get the playbook on how this all works, so I wanted to decode it.
As a sophomore at Reed College, I took an introduction to social movements class. We had an assignment to go and see a social movement. I went to the WTO protest in Seattle. I saw how when you put a collection of individuals who are interested in the environment together with union members fighting for a livable wage, the chemistry of networks coming together created the potential for transformation at a societal level. Immediately, that had me; I’ve been studying it ever since.
I find it exciting to understand what’s happening under our skin, at the molecular level, when we are in social connection, and how the pieces fit together into the dynamics of large-scale social phenomena. Networks are one of the best pathways to connect micro-level behavior to large-scale social outcomes.
Q: A lot of your work focuses on healthcare. Where does that come from?
Initially, I was drawn to healthcare because of the richness of the data. Studying network processes is fundamentally an analytic, data-driven enterprise. But I expect to be studying healthcare for the rest of my life, because it’s such a thorny complex problem. And answering questions has profound social implications for patients’ ability to live healthy and meaningful lives.
Early in my career I studied social movements—the anti-slavery movement and the agrarian cooperative movement in the 1930s. I have a huge regard for historical work and I love it, but I’ve moved to just studying contemporary problems because it’s critical to feel my work is engaging with public policy in a way that has a positive impact on society.
Q: Your new book, Social Chemistry, is aimed at a wide audience.
After years of documenting problem after problem that all fundamentally arise from a lack of social connection, with Social Chemistry I decided to shift to looking at solutions.
“I hope that by starting to understand social networks, we have the ability to address many of the largest social issues of our time—loneliness, issues around race, socioeconomic inequality, environmental issues.”
What I hope is that by starting to understand social networks, we have the ability to address many of the largest social issues of our time, whether it’s loneliness and a lack of social connection, issues around race, socioeconomic inequality, or environmental issues. Any process or problem that’s social in nature—and as a sociologist, I would say that’s everything—requires us to think about social solutions.
We all have networks. Our networks are fundamentally just the traces of social interaction that we have on a day-to-day basis, whether that’s bumping into a barista when getting a coffee in the morning or the more enduring relationships with our closest friends and family members.
We can think of those connections—our networks—as a map of where we’ve been in the past. That map of where we’ve been inevitably has important implications for where we’re headed.
If we want to understand how personal relationships, organizations, or societies work, we need to understand human interaction. If I need more social support, how do I go about getting it? If my company needs more innovation, how do I strengthen the human interactions that lead to innovation? If we want to address political polarization, how do we harness social processes to bring that about? The beauty of networks is that we can craft and change them.
Our relationships are among the most sacred things we have. The idea of being intentional about them is oftentimes morally off-putting. But what I hope to do in my book is call attention to the fact that being thoughtful, purposeful, and intentional about them can transform us as individuals and let us be better citizens and community members.
Q: Are all relationships the same on some level, whether it’s family or work?
My relationship with my husband is fundamentally different than my relationships with my colleagues, but the social structures that underlie them are the same. By starting to understand the rules that govern social behavior, it allows me to have a more meaningful conversation at the end of the night with my kids or my husband. The same understanding allows me to design an organization that has greater racial inclusivity.
The tools are powerful. Students in my classes take things I teach and immediately translate them into positive changes in all sorts of organizations. For instance, Dr. Rohit Sangal is in the MBA for Executives program and works in the Yale Department of Emergency Medicine, which has been hit hard by the scale of COVID. He applied discussions we’d had in class to implement strategies that promote teams, which in turn reduce stress and burnout in the department.
Q: How do you choose topics to look at?
I think of myself as a tool person. I look for problems that have fingerprints suggesting a network framework might help explain the underlying dynamics. My work and my way of seeing the world are fundamentally interdisciplinary in nature. One of the joys of the approach is that I get to collaborate with people in a wide range of disciplines. They have expertise in a given problem; I have a set of tools for analyzing systems and social networks.
Studying large-scale systems with computational approaches is an analytic framework. It’s necessarily lacking a psychological perspective. One of the benefits of being at Yale SOM is that not only do I have other colleagues using computational approaches, I also have colleagues who are psychologists. Being able to sit in seminars with people who are thinking about things like emotion, being able to ask colleagues questions like, what does trust really mean?, being in the classroom where students want to understand how to bridge the different perspectives—all of that has added layers to my work.
And I have been able to be a broker between different worlds that normally wouldn’t speak to each other. That has arisen from the commitment of our group at SOM to taking a multidisciplinary perspective.
Q: What do we know about the shape of people’s social networks?
We know from close to three decades of research in the social sciences that most people’s networks can be categorized as one of three types: expansionist, convener, or broker. Expansionists have extraordinarily large networks; if you ask them how many people they know named Emily or Adam, they’ll tell you two or more, which is a way that we can characterize how large someone’s network is. Most of us know around 650 people; expansionists know magnitudes of order more. Because of that, they have a lot of visibility, power, and influence.
Conveners often have lived in the same place and worked at the same job for a long period of time. Conveners tend to be friends with one another. They’re really invested in maintaining and strengthening relationships and because of that their networks are imbued with a lot of trust, reciprocity, and social support. Convening networks are good at guarding against loneliness and mental health disorders.
Brokers’ real strength is the innovation and recombination. Brokers tend to be in the idea import-export business. They have that chameleon aspect of being able to talk to different groups, which allows them to effectively bridge social worlds that wouldn’t normally come together.
There’s no one best network, but by understanding these fundamental social structures, we can improve outcomes.
Q: What’s an example?
New creations, whether they are ideas or products, are oftentimes essentially the recombination of existing ideas or products. One of my favorite examples is the printing press. While it seems radically new, it’s simply a coin punch and a wine press put together.
We spend most of our days talking to people who think like us and see the world like us. That inhibits the ability to recombine new ideas and new information in ways that spur innovation and creativity. From a social network perspective, if we want creativity and innovation, what we need to do is structure interactions where people who normally wouldn’t talk to one another come into conversation.
Q: You mentioned watching a social movement at the WTO protests in Seattle. How do social movements work from a network perspective?
Social movements catalyze different social connections of brokers, conveners, and expansionists. They tap conveners to spread ideas within a cohesive network. Brokers then bridge groups that wouldn’t normally connect, say, from lower income groups to wealthier groups. And expansionists add extraordinary reach and a degree of spontaneity and uncertainty that allow for really rapid spread.
Many decades ago, Stanley Milgram came up with this notion that we’re all connected within six degrees of separation. That’s known in the literature as the small-world effect. Even though there are now billions more people than when Milgram did his work, there are still just six degrees of separation between any two people. That has been re-documented by Duncan Watts and his collaborators.
We’re all already connected. Social movements figure out how to tap into the connections in a way that allows an idea or behavior to spread quickly and endure. If I want something to truly cascade at a global level, the trick becomes spreading a message along a pathway that is most likely to ensure that when it gets to someone they’re going to embrace the behavior or idea.
Q: How does gender play into social networks?
Gender is a core social variable. Men and women naturally build networks that look very different, in part due to predisposition, in part due to social constraints. The implications are huge, and play out in work-life balance, pay, promotion, and job retention.
Women tend to maintain and strengthen social connection through conversation; men to tend to build and maintain their relationships by doing things together. During the pandemic, men’s networks have shrunk by close to 30%; women’s networks have hardly shrunk at all.
Women tend to have social networks in which their home and social lives are differentiated from their work lives. That gives them more work-life balance, but it also means that they’re essentially maintaining two networks. They have to network harder than men to get the same outcomes.
However, women are better at reading social networks. People who are lacking in power are far better at reading social networks and understanding social structure. That’s because without power, having greater empathy and reading social structures effectively is critical to getting things done.
One of the pieces that I hope to call attention to in my work is how often we fall victim to a set of common cognitive biases that allow us to misread social systems. People in power are at great risk of doing that. Even though they have the greatest ability to change systems and promote propagation in a network, they often intervene in ways that are disadvantageous.
We are not going to be able to address systemic inequalities without understanding social capital, which is really just networks. We know, for instance, that getting a job through a network is beneficial to everyone. But Black job seekers have to network twice as hard to have the same chance of landing a job as a White job seeker.
If we don’t start thinking about providing early access to organizations or designing internship programs and networks that level the field, we’re not going to be able to address economic or racial inequality, because those are fundamentally social issues.
Q: Is your own field shaped by gender?
To say the field is predominantly male is an understatement. It’s very rare to see a female network scientist. The values that come from my experiences as a mother, as a woman navigating academia, are reflected in Social Chemistry. Even the cover of my book—there was a lot of discussion around it—has a feminine aspect and a softness. How I present and talk about this work was very important to me. At the same time, I’m a scientist. What was most important to me was that the science in the book had to be right.
Q: Where do you see the field going?
“Even five years ago, data and computational constraints meant we simply couldn’t analyze human connection in the way that we can now. The field is changing so quickly.”
We’ve been a part of this social system since the beginning of modern social history, but we’ve only had the ability to study it in a real way in the past 10 years.
I study how the intersection of how large-scale social networks impact our behavior on a moment-to-moment basis, using wearable sensors. Before the advent of the sensors, that work wasn’t possible. Even five years ago, data and computational constraints meant we simply couldn’t analyze human connection in the way that we can now. The field is changing so quickly. It’s amazing.