Jonah Berger needed a new pair of jeans, and it took an excruciatingly long time to conduct the research. He wanted something dark blue. Something not too tapered. He went online and scanned different styles. He went to several stores and tried pairs on. He narrowed his options down. Then he started thinking about what the jeans said about him. He’s not a Diesel or Lucky guy. He’s not really a Banana Republic guy, either, but his last pair of jeans was from there, and so were the ones before. “It took two or three months,” he says, “but I finally thought, ‘I’m gonna go with these, and it’s gonna be okay.’”

Cause and effect: Berger and Zoe play catch at home.

Cause and effect: Berger and Zoe play catch at home.

He’s wearing the jeans now. “They’re Banana Republic,” he says, before a deliberate pause. “Yeah. They’re not magic.”

If there’s a lesson to be learned from this, it’s that you shouldn’t go shopping with Jonah Berger. But the bigger lesson, really, is that any decision, even one we don’t agonize over, gets made because of dozens, even hundreds of influences and triggers. Berger is wearing a colorful, casual button-up instead of a t-shirt because the collar conveys at least a bit of the formality of being a professor. His wife, Jordan Etkin, is an associate marketing professor at Duke University. So he came here to an old service station turned-coffee shop in a gentrifying section of Durham, North Carolina, because it was dog-friendly for his pit bull terrier, Zoe, who’s sitting next to him at a picnic table, getting occasional rubs behind the ears. “What I find great about dogs is, whatever breed you have, they’re great,” he says, and even that statement sounds like Berger has given it a lot of thought.

Berger, just 36 years old, is now finishing his 10th year as a marketing professor at the Wharton School. He’s published two New York Times bestselling books: Contagious: Why Things Catch On, and, most recently, Invisible Influence: The Hidden Forces That Shape Behavior, published last year. He’s conducted hundreds of social science experiments and published dozens of papers. He’s consulted with a slew of companies big and small—helping launch Google’s new phone, providing input on a new Facebook product, crafting development messaging for the Gates Foundation. He has given a multitude of talks and is a popular guest on television, radio, and podcasts.

If you’re lucky enough to catch him out of the classroom or the media circuit, in person, Berger speaks enthusiastically, using his hands to make bigger points. He answers questions without an “uh” or “um,” jumping in quickly, usually starting with an interesting anecdote that illustrates his larger point; after he’s finished, you can’t help thinking he was given the question weeks in advance. He doesn’t speculate. What he says comes from some sort of research or science, and if he doesn’t have a fact-based answer, he admits it. A conversation with Berger is rapid-fire. His replies are both thorough and succinct and often come with the perfect analogy. When you talk with him, you can learn a lot in a short amount of time.

And even as he talks, his mind is always churning. It’s a sunny day with constant wind, and from time to time, 40 mile-per-hour gusts blow dust, leaves, and small bits of gravel up the street and into people’s eyes and faces. In the midst of this swirling air, a man gets out of a pickup truck next door, fires up a leaf blower, and starts a futile 20-minute effort to clear off the parking lot.

Berger can’t help but look at this. “Why is he blowing leaves in the wind?” he says. “Why is this windy day the day to blow leaves?” The answer doesn’t come. The man eventually gets back into his truck and drives off, but you can tell Berger knows that as improbable as it seems, there has to be a reason for the man’s behavior. “There’s always,” he says, “a richer answer to anything.” He’s constantly searching for those answers, whether he’s working or not.

Jonah Berger was born in suburban Washington, D.C. His mother, Diane Arkin, is the senior lecturer at the National Gallery of Art and uses simple language to help visitors and docents understand complex paintings and sculptures. His father, Jeffrey Berger, is a detail oriented retired labor lawyer. When Berger was born, Jeffrey bought a book, Total Baby Development, written by a Czech author who insisted that movement and exercise in infants lead to better cognitive development. So Jeffrey threw his new son in the air and rolled him on exercise balls. “I don’t know if it had any influence on him,” he says, “but we sure had fun.”

At nine months old, Berger sang “Happy Birthday” to his father. At three years old, he couldn’t read, but he’d memorized the books his parents read to him and could recite them from memory. When he was in preschool, one of his teachers worried that he had concentration issues, since he’d look upward during storytime. She was less worried when, after she’d ask a question about the book, Berger’s hand would shoot up—and he’d have the correct answer. One time, she caught him counting out numbers, somewhere up in the 5,000s, while he stared at the ceiling. He was counting the dots on the tiles. As a teenager, he kept his room messy. That was okay—the more complex things were to him, his father says, the more interesting. He was drawn more to Super Bowl ads than to the game. He wore Nikes because he loved their commercials. His grandmother ran her own research company that conducted focus groups. Berger was fascinated by them.

At Stanford, Berger wanted to be an environmental engineer until he read a paper that caught his eye. It argued that the design of our homes influences our kids: In individual houses, kids play in the yard, where we can see them, but in high-rises there is no yard, and kids are less likely to play with the neighborhood children, which affects how they interact later in life. That was social science, he discovered, and he quickly realized that studying it was what he was really interested in.

By the time he earned his doctorate in marketing from Stanford in 2007, he was in demand. “From the beginning, we believed he was the star,” says Eric Bradlow, chair of the Wharton Marketing Department. The school didn’t have an open position, so it created one. Bradlow was interested in Berger’s ideas and research but also in his enthusiasm. “The minute you talk to him,” Bradlow says, “you share in that energy.”

The first class Berger taught at Wharton, at age 27, was his own creation. Contagious: How Products, Ideas, and Behaviors Catch On was all about how ideas spread, why certain things stick in the memory, what people imitate, what people avoid, and what was happening in the burgeoning field of social media studies. Not only were the topics fascinating; so was the way Berger discussed them. “He was excited to share with us this new way of looking at things,” says Keri Taub C12, who credits Berger for igniting her interest in a career in business. “A class like this hadn’t existed before.”

Taub, now a student at Columbia Business School, started applying Berger’s ideas in another course. One class project was an exercise in which students were given a list of fictional people who needed organ transplants. Each group had to pick one, then try to convince others that its candidate should get the transplant. Other groups relied mostly on data. Berger’s course had taught Taub that statistics are important, but that logical, reasoned arguments aren’t always as persuasive as emotional appeals. So one member of her group played the candidate’s mother. Other members pretended to cry. “We won by a landslide,” Taub says.

A few students from the class became research assistants for Berger’s first book, Contagious: Why Things Catch On, published in 2013. He had been inspired by Malcolm Gladwell’s The Tipping Point and wanted to write something similar that was grounded in science and research. The resulting book became a best-seller and is the equivalent, says Berger, of “a day or two of the course.” Even the color of the cover was meticulously researched. He knew that a bright shade would make the book stand out on bookshelves in stores or while people read it in public. Berger consulted color experts, who told him orange was both bright and active. (Blue, by contrast, is a passive color.) So orange it was.

The ideas behind the book had deep roots in marketing, where trying to figure out word of mouth and virality had occupied companies for decades. But by 2012, the internet and social networks had brought those issues to the forefront. Ideas, videos, and memes became huge hits in ways people hadn’t conceived of before. When people wanted to know why, they sought out someone who’d been doing research for years and could explain it in a way that was easy to understand. Thanks to both the book and Wharton, they found Berger.

Information can spread more quickly now, he says, but most of it still travels in old-fashioned ways. Most people think 50 to 70 percent of word of mouth happens online; in reality, it’s closer to seven to 10 percent. That figure may be slightly higher among younger people, but the majority of influence still happens offline. “Why are we so focused on social media?” Berger asks. “Because we can see it.”

Social media has changed us at the margins, he says, but not at our core. Anyone can create and share content now, but we share content for the same reasons we’ve always shared stories: We want other people to like us, or to think we’re interesting or clever. Social media has just made a game out of it, one where victory is often measured in likes, retweets, and pins. “Some of the basic principles are the same,” Berger says. “You’re motivated to win. The closer you are to winning, the more competitive you get.”

Most recently, social media has been dominated by a man who argues that we don’t win anymore. Berger thinks the rise of Donald Trump may have something to do with the amount of information we receive now. “The model before was that someone said something and that was on the record,” Berger says. Presidential hopefuls Al Gore and John Kerry were both undone by perceptions that they were “flip-floppers” who changed their minds on key issues. Yet Trump’s shifts on a variety of positions seemed to have little impact on last November’s election. “There’s so much more information now that so much less attention is paid to any one piece,” Berger says. It’s not so much about staying on message—it’s about getting your message through to a public that’s bombarded by so much stuff.

Trump’s style and message are the polar opposite of his predecessor’s, but both men touched on something that made their messages effective. Berger’s research has shown that content evoking one of three emotions—anger, anxiety, or awe—is more likely to be shared. Depending on your viewpoint, Obama and Trump inspire at least one or two of those factors. Trump has also hit on something else: brevity, which is effective in an era in which people scan and share stories based on the headlines, not the articles beneath them. Berger doesn’t expand on Trump’s ideas other than to wonder whether he ran his campaign this way on purpose or just got lucky. He’s more interested in why Trump’s message worked than in its content. “We’ve elected a president who fits with the way we are now,” he says, “with the way we transmit information, for better or worse.”

What sets Berger apart, everyone seems to agree, is his voluminous memory, his quick recall, and an ability to see connections that others can’t. He’s direct. (“He’s answering your question,” says his dad, who has a house in the D.C. area. “Where I live, no one answers anything.”) He also uses his research to communicate his ideas effectively. That can bleed over even into personal conversations. Sometimes Berger begins his answers to his dad’s questions with, “The studies say… ”

“That’s fine,” Jeffrey will reply, “but what do you think?”

Berger is data-driven, but he’s not a robot. His studies show that making a human connection, striking a nerve, and opening up personally are all important in getting your point across. “He’s very clear for a reason,” says Ezgi Akpinar, a marketing professor at MEF University in Istanbul who co-authored two research papers with Berger. “He really puts those principles into practice.” Berger likes to collaborate, and only a few of his papers don’t have any co-authors. He often listens first, then provides feedback before asking for another opinion. “Most of the time,” Akpinar says, “he understands what I’m thinking more than I do.”

Berger’s second book, Invisible Influence, opens by arguing this point: We’re good at seeing how others are influenced, but we have a big blind spot—ourselves. We think we’re independent, free-thinking. And yet we succumb to social pressure just like everyone else. We say soda, pop, or Coke, depending on what part of the country we live in. We follow others when deciding what music to listen to or what clothes to wear. We mimic each other, and with good reason: Research shows that negotiators are five times more successful when they mimic the person they’re negotiating with. After a short conversation with Berger, I find myself talking with my hands, too.

Invisible Influence challenges assumptions, like the notion of individuality. Consider that you’re most likely to have met your spouse at work or school, because that’s where you spend the most time with similar people. People often discover new things online by scanning lists of what’s most downloaded, most read, or most popular. “There’s this idea that difference is the most important thing—that the more unique we are, the more successful we are,” Berger says. In reality, he argues, there’s a lot of value in seeking out sameness.

That perspective has a lot of people interested in what Berger has to say. “Why are people calling? The research,” says Bradlow, the marketing chair. As long as research is at the core of Berger’s work, “His success is certain.” It doesn’t hurt that the messenger—personal fashion conundrums aside—is so effective in translating his research to the masses.

Science is still at the core of what Berger does. Lately he’s been interested in textual analysis, and in pulling behavioral insight out of it. How can you predict whether a movie, a song, or an article will be a hit? What about the text makes something work? What story structure or length encourages people to keep reading? What sorts of lyrics keep people listening, and what kind of action or dialogue might make them tune in week after week? This, potentially, could be another book. Or not. The books were a challenge he wanted to take on, but he concedes that writing doesn’t come naturally to him.

Wharton_Spring2017_0405-168I’m selfishly intrigued, so I break the fourth wall and ask Berger a rather meta question: What would make this story about him go viral? “More controversial content is shared more,” he says. “Until it gets too controversial.” No luck on that point. He then directs me to a study he did on New York Times articles in 2012—one that factored into his first book, Contagious. Overall, viral stories tend to be more positive than negative, it showed; sadness kills virality. Berger says concrete examples work better than abstract ones. He suggests leading off with a surprising piece of information, something that opens up a mystery. “I have no idea what that is in my own story,” he concedes. The puzzle of the ill-timed leaf blower from earlier in the story? Maybe it’s a cliffhanger. Or it might only provide amusement to landscapers.

This much is positive and undeniable: Berger loves his work, and he lives it, too. He seems to know how to apply it to everything, even an interview. But it hasn’t streamlined his personal life. He self-analyzes all the time. When his tastes change, he wonders why. When he does something, he looks inward and outward. “I think it does make it a lot more complicated to make decisions,” he says. “It’s hard not to see everything.” And that’s the thing about Berger: He can step away from work, but he can’t shut off the curiosity.

Right now, he’s curious as to why his dog won’t listen. As we talk, Zoe gets up and idly walks around. Berger tugs on her leash, asking her several times to come back closer to him and sit. She lazily stands, not bothering anybody but not obeying, either. Finally, she lies down at Berger’s feet, soaking up the sun. “I enjoy seeing people puzzles in the world,” he says. “But sometimes, it would be simpler to be a dog.”

Jeremy Markovich is the senior writer at Our State magazine. He and his family live in Greensboro, N.C.

Published as “Inside the Mind of Jonah Berger” in the Spring/Summer 2017 issue of Wharton Magazine.