Why We Love Drunken Facebook Pics, Online Reviews and Gangnam Style

Wharton "viral science" prof Jonah Berger talks about his new book, Contagious: Why Things Catch On

Congratulations! Your new book, Contagious: Why Things Catch On, is really catching on.
Thanks. The Today Show just called and wants me for an interview.

You’re the only person I ever heard say you watch TV for the commercials, not the shows.
It’s true. I was watching with my family recently, and they had the commercials muted so they could talk. I asked them to turn them back on. When I was in college, I used to duct-tape ads I liked all over my dorm room’s walls.

In Contagious, you say that people share things that make them look good to others. So how do you explain drunken Facebook photos?
For some people, that’s the identity they want to show the world. For some of us, it’s catching a big fish, or posing with a fancy car. Some teens want to show they like to party.

The ex-CEO of J.C. Penney, Ron Johnson, clearly didn’t read your book. He’s the guy who had the bright idea of eliminating sales and discounts and just lowering prices for everything, all the time.
People love deals. We love getting something on special. It makes us feel compelled to buy; it’s a behavior trigger. But the CEO was right that something had to be done. Penney’s big problem was that there were so many deals. People start to realize: If every day is a deal, why should I buy now?

Your research shows that word-of-mouth guides half our purchasing decisions. Why are we willing to believe online reviews by people we don’t even know?
At least it’s someone who’s not the company. We know what the company is going to say: This product is the best thing ever. The reviews may be by strangers, but we trust that they’re not getting paid.

You did a fascinating study on how where a person votes affects how a person votes. People who vote in schools, for example, are more likely to vote for education funding. What would be the best place to have people vote?
The scientist’s answer would be a colorless box with no information in it. But if we could shift away from schools and churches to places with a less religious atmosphere, that would be better.

A lot of your research proves one thing: that humans aren’t rational creatures. We’re no different from birds attracted to shiny things, are we?
Our behavior may not be traditionally rational. But a lot of what our decision-making is built on can be analyzed psychologically.

What you’re really doing is helping businesses to manipulate our behavior in insidious ways. Have you no shame?
I’m not teaching how to manipulate consumers. A bad product isn’t going to get good word-of-mouth. It’s not about how to get bad products to be popular. It’s about how to get good products the attention they deserve.

How is user-generated content changing the world?
The hope is that it’s a democratizing process. It used to be that movie companies decided what movies would be hits. Record companies decided what songs would be hits. Political families decided who would win elections. The hope is that we’re democratizing choice.

One of your studies showed that even negative reviews in the New York Times sell books. Um. Your book didn’t get a very good review there.
I would have preferred a glowing review. Anyone would. But it’s gratifying just to be reviewed by the Times. And what I care about more is the fact that people are really finding the book useful. Academic research is lots of fun, but if nobody’s using it, it’s not as fun. The book is helping get good ideas out there.

So can you pretty much predict the future now?
If you had shown me the “Gangnam Style” dance and asked if it was likely to go viral, I would have said yes.