Jonah Berger, a professor of marketing at Wharton, has spent more than 15 years investigating social influence. In his 2013 book, Contagious: Why Things Catch On, he explains how and why certain products and ideas become massively popular. In his new book, Invisible Influence: The Hidden Forces the Shape Behavior, Berger focuses on the immense sway others have over the choices we make—whether we’re imitating or differentiating from them—often in ways we aren’t aware of. Berger and I spoke by phone about the often surprising findings he draws on in the book, the tension between fitting in and standing out, and how social influence can best be wielded. Jessica Gross writes ..
How did you first become interested in studying social influence?
I’m from the D.C. area originally, and have a friend who’s a lawyer there. I was talking to him, and he was complaining that all D.C. lawyers drive BMWs—when they make it, they go out and buy a BMW. He said, “Look at how D.C. lawyers are all conformists.” I pointed out that he had actually himself just bought a BMW. And he said, “No, no, but I bought a blue one. Everyone else buys gray ones.”
What I thought was really interesting about that story was a few things. One, he saw everyone else as influenced, but not himself. Sometimes we recognize that social influence is out there, but we think only other people do it. We don’t see it in our own lives. And yet, here was a great, amazing, powerful example of someone’s own life being shaped by what others are doing.
But also, influence isn’t a simple thing. It’s not just doing the same thing as others. Often, when we think about influence, we think, “If someone else jumped off a bridge, would you jump off a bridge?” But influence is actually much more complicated than that. Influence is actually like a magnet: sometimes it attracts and leads us to do the same thing as others; other times it repels and leads us to do the opposite thing. And sometimes, like with this example of the BMW, it actually leads us to be similar and different at the same time, so that we’re optimally distinct. We end up being similar on one dimension and different on another.
And so what I wonder is, when do these different things happen? When does influence lead us to be the same? When does influence lead us to be different? When does it lead us to go along with the group? When does it lead us to be more independent? How do others motivate us? How do others de-motivate us? And how can we use all this science to live happier and healthier lives?
You mentioned just now, and describe in the book, that we’re not aware of how influenced we all are by those around us. I found this curious and surprising, since I’m heavily influenced by those around me—and I know it! For example, is it possible your friend with the BMW was being defensive about how much he wanted to fit in, but deep down, he was well aware of it?
Well, there are a couple reasons that we don’t see ourselves as influenced. So one, as you already pointed out, at least in American culture, is that we tend to think about influence as a negative thing. You know, “Don’t be just a sheep, don’t go along with the herd. Be an individualist. Be a special, different person.” We have a whole day about being independent in the United States, Independence Day. And so being different than others is a cultural value.
And so you might say, “Well, since being different is valued, if I’m in American culture, I don’t want to see myself as influenced.” And that’s definitely true. There are some times where we don’t want to see ourselves as influenced because we see influence as a bad thing. But it’s not just that. Even in situations where influence is a good thing, we still don’t think we do it. And so it’s not just that it’s a bad thing, it’s that often we’re unaware it occurs.
So, you know, I just bought a new pair of sneakers. And I think I bought them because I like the color and I like the way they fit. But what I don’t realize is that I might have seen a bunch of other people wearing similar shoes recently, and that’s why I bought these shoes. I may not have realized that those people were wearing the shoes, or even if I didn’t realize that they were wearing them, I may not have been aware of the link between them doing it and me doing it.
Influence often happens unconsciously or below our awareness. Because we can’t see it, or when we look to our minds, we don’t see any evidence of it occurring, we think it doesn’t affect us. But just because we’re unaware that it affects us doesn’t mean it actually doesn’t.
And in the example I gave, my friend focused on how the color of their car that was different. They’re driving pretty much the same car but they focus on how the color is a different one than someone else’s. And so even when we do very similar things, we tend to focus on ways that we’re different because we don’t want to see ourselves as influenced by others.
You include some fascinating studies and findings in this book, which I hoped we could get into. Could you start by walking me through the study that asked college students in a lecture class to rate various women’s attractiveness?
Imagine you’re a college student and you’re in a psychology class all semester long at the University of Pittsburgh. Class meets a few times a week, and it’s a large lecture class, lots of people. Towards the end of the class, the professor says, “Hey, for part of class we need you to do a survey for us.”
Part of that survey is they show you images of different women and ask you to rate how much you like them and how attractive you think they are. Pretty easy, right? You look at one woman. She’s about the same age as you, she has brunette hair, or whatever it may be. You look at another woman, she has blond hair. You rate them based on how attractive you find them. Okay. Nothing surprising here.
What was interesting is that this was actually part of an elaborate experiment. The women looked like regular students, but they were actually what psychologists call confederates, or sort of stooges for the experimenter. The professor manipulated how frequently these people—these individuals that seemed like other students—came to class over the course of the semester. One woman came to class 15 times over the course of the semester, another woman came 10 times, a different one came five times, and the fourth woman came no times. The professor was interested in how the number of times the students came to class affected whether other people thought they were attractive.
Stepping back for a second, you would think, “Well, why does how frequently I see someone matter in terms of how attractive I find them? Certain people like certain types, other people like other types. Why should it matter how many times you see the person?”
And indeed, what I think is particularly interesting about this is if you ask someone who’s in a relationship why they like their partner, they’ll give you a long list of reasons. “They’re so funny, they’re so attractive, I like their personality, there are so many reasons why I like them, so many reasons that this person is the only one for me. I couldn’t imagine being with anyone else.” There’s this notion in our culture that there’s just one other person for us, that we’re two peas in a pod—you know, “You complete me.”
That makes sense, except for one important fact. Most people meet the person they end up marrying at one of two places: at work or at school. That, by itself, isn’t surprising. We spend a lot of time at work and we spend a lot of time at school. But what’s unusual about that is if there’s just one other person out there in the world for us, what’s the chance that that person happened to work at the same office, or happened to go to the same college we did and happened to take the same class we did, where we met them? Could we really be that lucky?
So, in this study, they averaged all the ratings. They looked across people, and sure enough, some folks preferred blondes, other folks preferred brunettes. Some people preferred redheads. But when they looked at the data, how frequently someone came to class impacted how attractive that person seemed. The person who came to class 15 times was seen as more attractive than the person that came 10 times, who was seen as more attractive than the person who came five times, who was seen as more attractive than the person who came zero. And it wasn’t that these people were more attractive to begin with—if you showed these same photos to a set of people who had never seen any of them before, they would have been equally attractive. The mere fact they had come to class more times made them seem more attractive.
But what’s so interesting about this is that if you asked the students rating the women why they found them attractive, they would have given the usual litany of reasons. “They look a certain way, they have a certain glint in their eye.” They never would have said, “Oh, it’s because I saw them more times.”
The more we see something, or in this case a person, the more we like it. Often, this happens without us realizing it. So even with something so important, like who we marry or who we spend our life with, it isn’t just our own personal preferences—whether we like brunettes or blondes, whether we like our men tall, dark and handsome or short, stubby and less handsome, whatever it may be. It depends on these social influence factors: how many times we’ve seen them, whether they happen to be in the same environment as us.
Correct me if I’m wrong, but I believe that you and your wife met at a conference, which would seem to be an exception to this rule. So how do you think about that?
Well, in fact, the story of me and my wife actually goes very much along the lines of what we just talked about. Everyone likes to see falling in love as a magical process—the first time you saw them, you just knew. And indeed, I would like to see my own relationship that way.
But if I’m being honest, if I’m looking at this as a social scientist, it wasn’t like the first time that I met my wife, stars went off in my head and I fainted and I knew. It was much more of a slow, deliberate, gradual process. After time, I got to know her, and finally I said, “Wow, this is really great.” But I didn’t know that the first time I met her or the first time I saw her. The more times I saw her, the more I got to know her and the more I liked her. And so again, I think we like to see our lives as driven by our own personal preferences, but social influence often plays a big role, too.
Romantic components aside, when I read about the experiment with the women in the lecture course, I was reminded of what happened to me when I started seeing Ugg boots. When I first saw them—it must have been in high school or college—I remember thinking, “Those are the most hideous pieces of clothing I’ve ever seen.” I was extremely dismayed to find that, over time, the more Uggs I saw, the less repulsive I found them. One day I even found myself thinking, “Those aren’t bad—maybe I’ll get a pair!” I felt like a sheep who had no personal taste. So can you talk about the adaptive purpose of this tendency to like something that we become familiar over time?
Sure. So imagine that every time we saw something, we had to figure out whether it was good or not. Every time we saw a person, every time we saw an item of food, every time we saw anything, we had to figure out: it is safe or is it not safe? Is it poisonous or is it edible? Is it dangerous or is it good? Imagine if a baby, for example, had to figure out, “Okay, is this figure that comes and picks me up every morning and puts me to bed at night, is it going to take care of me or is it going to kill me? Is it helping my life or is it hurting my life?”
It would be extremely effortful if every time we saw something, we had to figure out whether it was good or not, even if it was the second or third time we saw it. And so, one, that’s why we have memory. But second and more importantly, we start to form associations with things we’ve seen before. We say, “Well, okay, if I’ve seen this a number of times before and it hasn’t hurt me in the past, it must be pretty good. If this caregiver I’m seeing all the time is around a bunch and it hasn’t hurt me, it must be good.” That helps children bond with their parents. It helps us figure out the world around us and interact with that world in a simpler way than might happen otherwise.
So it really has some biological or neurological basis in helping our lives. But it can be applied even in cases that don’t make as much sense, like how, as we’re talking about, merely seeing someone more makes us find them more attractive. But if you think about it from an old evolutionary basis and old sort of tribal basis, if someone’s in your tribe and they’ve been good to you, you see them a bunch of times, you know that they’re good and so liking them is not a bad thing.
One bit of research that fascinated me was that spouses’ faces become increasingly similar over time, if they’re a good couple, because they mimic each other’s facial expressions and thus get wrinkles in the same spots.
Right. Not only do we like things, products, or people that we’ve seen more often, but we also tend to mimic or imitate the people that we spend time with. So whether consciously or not—and it often happens unconsciously—if you’re sitting in a meeting and you’re crossing your arms, someone else may cross their arms. If you scratch your cheek, someone else may scratch their cheek. The mere fact that that we engage in a certain behavior, use a certain accent, or say a certain word increases the chance that others around us do the same thing.
This even applies, as you noted, to spouses. If you look at the data, spouses actually look more similar to each other than you might predict by chance. And you could argue that of course this makes sense because people don’t marry random others, they marry other people who are a similar age as them, and from a similar demographic group. So maybe we marry people who already look like us to begin with. And that’s definitely true, but it’s not the only thing going on. Because if you look at married couples when they begin and they get married, versus later on in their lives, the longer they’ve been together, the more similar they look.
And it’s not just that you eat the same food or hang out in same environment, like Florida, so you both get wrinkles from hanging out in the Florida sun. What it ends up being is that we mimic those others around us. If your spouse comes home and tells a story about how angry they are, you get angry. If your spouse tells a funny joke and they’re smiling and laughing, you start smiling and laughing. The fact that we engage in the same emotional expressions at similar times means that we start to make the same expressions. Just as two pieces of paper folded again and again in the same way get creases that are the same, making smiles or frowns at the same time together puts that pattern into our faces.
Can you talk about the relationship between how empathetic a person is and how much they practice this physical mimicry?
Part of mimicry is driven by empathy. You know, empathy is really paying attention to others, being aware of others and noticing others in the environment around us. The more empathetic we are, the more we tend to mimic. And so if we’re really paying attention to the people around us and what they’re doing and how they’re acting, we’re more likely to notice what they’re doing. It’s more observable to us. And as a result, we’re more likely to imitate it.
You describe the delicate balance between when and how much we want to imitate others, and when and how much we want to differentiate ourselves. Your study of the relationship between hurricanes and baby names seems to really encapsulate this tension.
If you ask people why they picked the baby names they did, again, they’ll give you the usual personal story: “I picked this name because it ran in the family.” “I picked this name because I liked the way that it sounded.” “I picked this name because it was a fusion of my husband’s name and my own name.” We all think that individual reasons drive our choices. Yet if you look at the data, there are some interesting patterns. Many kids, for example, get to kindergarten or first grade and there are three or four other Katelyns or Bobbys. If we’re all making these individual choices, based on our own likes and dislikes, how do we all end up making similar choices at the end of the day?
We looked at over a hundred years of baby names—the number of children given every name, every year. We were interested in how what names had been popular might shape what names are going to be popular. Were there patterns in how what was popular last year shapes what becomes popular this year? We also wondered how factors in the environment would shape baby names, so we looked at hurricanes, thinking that maybe people avoid names that are associated with hurricanes.
Interestingly, we found that when something like Hurricane Katrina happens, people don’t choose the name Katrina, but more babies are born with K names. That is, people pick other names that sound similar. And indeed, when we looked at the rest of the data, we found the same pattern. If, for example, Laura is popular one year, Laura may or may not be popular the next year, but other L names are more likely to be popular.
So people aren’t picking the exact same name that’s been popular. And that makes sense, right? They don’t want their child to get the same name as everybody else. Jack’s a really popular name, so they say, “Well, that’s too popular, I don’t want to name my child Jack.” Yet they end up picking a similar name even without being aware of it. They end up picking another name that starts with that J sound because they heard Jack more often and because of that, that J sounds more familiar, which makes it sound better, and makes people more likely to give that name to their child.
And so when we’re picking these baby names, we’re trying to be similar and different at the same time. I talked about the idea of being optimally distinct. We don’t want the same thing as everybody else. Yet we also don’t end up picking something completely different.
Can you talk about applying this knowledge to influence people to make positive societal change?
I think it’s really important to think about, if people follow others, how we can use that to live happier and healthier lives, and to make the world a better place? Part of it is not just thinking about the functional reasons for doing something, but also what it signals to others.
For example, I talk about some really interesting research in the book that has found that one reason women are underrepresented in science, technology, engineering and math, is not just because of bias, which certainly exists, or issues with the right classes and the right places, but also the fact that women don’t see those careers as something associated with them. They think about science, technology, engineering and math—they think about geeky guys in Star Trek T-shirts. And so part of the reason they’re avoiding these careers is because of the identity they associate with that.
Or similarly, I was working at a project recently with a group of conservatives that wanted to get clean energy to catch on among conservatives. You would think clean energy would be a clear, conservative value, something conservatives would support. Clean energy saves money; it reduces our reliance on oil, which helps national security; it even allows people to be independent, which creates smaller government rather than larger government. So you would think conservatives would love clean energy. But they don’t like it.
If you ask any prominent conservative politicians why they don’t support clean energy—one of them said, and I think they put it really well, “Well, I learned that Al Gore was for it, and if Al Gore supports it, it’s probably not the right thing for me.” What’s really interesting about that is it’s not just about what clean energy is, it’s about what it signals, or what it communicates.
And so as we’re thinking about non-profits, as we’re thinking about important causes, we need to think about not just those values that those causes have, but what do they signal or communicate to others to support? What does it say, for example, to engage in a certain behavior, or to give money to a certain cause? What does it say to support one political candidate rather than another, and how can we change the signals associated with these behaviors or these ideas to encourage people to do the right thing?
There’s also a dark underbelly to social influence, which is propaganda. At a museum exhibit recently I saw money that the Nazis had printed with anti-Semitic messaging. Can you talk about the potential for this knowledge of how social influence function to be used for social ill?
I often describe what you just talked about as identity hijacking, or associating a particular person or idea with something that is negative in order to sink that person or idea. Going back to Al Gore, he was framed as a liar—even though it wasn’t clear he was a liar—which really sunk his political career and aspirations as a President.
I think what’s important to remember is that social influence is a tool just like any other. It can be used for good and it can be used for evil. It’s not that social influence itself is bad. You know, sometimes we think that following others is a bad thing. Just as often, following others can be a good thing. Think about if we couldn’t rely on online reviews to pick stuff, if we had to figure out what restaurant to go to all by ourselves, we could never ask anyone else. It would be a lot of work. Not only would it not be very fun, but it would be exhausting. We could never go to a new restaurant because it would take so much work.
Relying on others, using others as a signal of information, is a valuable tool that makes our lives better. Sure enough, yes, social influence can also lead us astray. It can lead us to make worse decisions in groups and it can lead us to make bad decisions in our personal lives. What I talk about is how we can take advantage of its upsides and avoid its downsides, how when we understand how influence works, we can choose our own influence and use that to live better lives and help others do the same.
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Jessica Gross is a writer based in New York City.