James Fowler explains how smoking, obesity, and happiness can be contagious.
In their pioneering research, James Fowler and Nicholas Christakis have shown how happiness, obesity, and smoking travel through our social networks. Their work has captured the media's attention. In September, The New York Times Magazine devoted a cover article to their research called "Are Your Friends Making You Fat?" and Oprah chose their book Connected: The Surprising Power of Our Social Networks and How They Shape Our Lives for her fall reading guide. GOOD talked to Fowler about how our friends influence us, why there's a sweet spot for diversity, and the difference between Facebook and real-world social networks.GOOD:How did you come to study how social networks influence us?JAMES FOWLER: I had these crazy ideas in graduate school about how political action is really a result not of independent decision-making but of our connections to other people. For a long time, for 50 years, we've been asking this question "Why do people vote?" There are millions of people out there and even in our closest political election, the result is decided by thousands of people. If any one of those 1,000 people didn't vote, the result would have been exactly the same. [But] that's the wrong way to think about it. Voting is about influencing other people. When one person votes, it increases the likelihood that their friends will vote.I did some research on this, and at the same time, Nicholas Christakis had been studying his own big social science problem: the widower effect. It's the idea that in a spousal couple, when one partner dies, the other person has a significant increase in the risk of dying themselves. As with voting, we knew a lot about how one person affected another, not about what happens after that. It's almost like we had been studying a bunch of dominoes on their sides, and we looked to see what happens when the first domino fell into the second domino, and then we walked away.G: One of your findings that's received a lot of attention is that obesity spreads from person to person. Do good health behaviors spread too?JF: When we focus on obesity what we're really looking at is weight gain and weight loss. The effects are symmetric. In a medical journal we often express this in terms of the standard thing people care about. That's why we emphasized weight gain. But weight loss spreads just as strongly as weight gain as far as we can tell. The one thing that we found asymmetry for was happiness. We found that happiness spreads more reliably than unhappiness. Each happy friend you have increases the likelihood that you'll be happy by 9 percent and each unhappy friend decreases it by 7 percent.G:Are there certain kinds of people who transmit these behaviors or emotions more than other people?JF: We find that same-gender relationships tend to be more influential than opposite gender relationships, which explains why friends tend to influence people's weight outcomes more than spouses. Another thing we found in the smoking study was that people who were more educated were more likely to influence and more like to be influenced by other people to either start or stop smoking.G:Wow. What's the explanation for that effect?JF: I don't know. But I think part of the function of education is to help people to adopt norms and to promote norms. It's part of making us more similar. So because of that I think it's easier to spread ideas between those kinds of people.G:I guess education might in a way make people more flexible, too.JF: I don't know if that's true, though. In politics, for example, the more educated people are, the more extreme they tend to be and the less likely they are to be influenced by people with opposing points of view. It's funny, because I'm a professor, and I have a lot of education, so I have a bias. I want to think that education is good thing, but in some ways education might actually be a little limiting.G:How has coming to these conclusions influenced how you go about your own life, or has it?JF: Oh, it absolutely has. After I concluded the obesity study, I lost five pounds and I kept it off. I realized: If I do this to myself I'm not just doing it to myself I'm doing it to my friends and my family, and to their friends and their family. After the happiness study, I became much more sensitive to putting myself in a good mood before I come home at the end of the day because if I make my son happy, there's a good chance I'm making his best friend happy and his best friend's mom happy.G:What do these results say about the merits of diversity in a community? Is a place with lots of diversity like Manhattan better than a homogeneous small town?JF: My guess is that diversity in ideas is a good thing. Although too much diversity in ideas could be a bad thing because if you can't talk to any other person because their ideas are so different, then you're never going to be able to cooperate and get things done. There's this sweet spot in terms of how embedded people are in [social] networks, and a sweet spot for diversity that's going to encourage maximum creativity and provide maximum ability for us to realize our potential.G:Do we know whether habits and attitudes are transmitted through digital social networks like Facebook or Twitter in the same way as real-world social networks? JF: These online networks are the same but different. Health behaviors spread between deep social contacts. We shouldn't expect our 110 Facebook friends to have as strong an influence on us as our five or six closest friends. But we've started looked at the structure of the networks of in terms of who's smiling in profile pictures as opposed to who's not smiling. If you just look at Facebook friends, there's no pattern. But if you restrict that network to picture friends-and by "picture friends" I mean people who've tagged you in a photo and whom you've tagged in a photo-suddenly we're back down to an average of five or six people, just like the five or six close social contacts in real life, and suddenly we do find associations in the profile pictures that people put up for themselves. We're going to be collecting a lot of data from Facebook. But you have to figure out who someone's real friends are.G:Are there any lessons I should take about how I choose my friends or the responsibility I have for other people's health?JF: One thing people think about is, "If I'm being affected by all these people out there then what happens to free will?" I'm just a piece of flotsam floating on these waves. I tell them that just as they influence you, you influence them. If you tell someone that they don't influence anybody they're not going to take any responsibility for their actions. But if you tell them that they influence 1,000 people, I think it suddenly changes the way they see the world.Photo by flickr user (cc) saneboy