#32. A Summary of ‘Contagious: Why Things Catch On’ by Jonah Berger

contagious why things catch on by jonah berger

‘Contagious: Why Things Catch On By Jonah Berger (Simon and Schuster; March 5, 2013)

Table of Contents:

i. Introduction/Synopsis

1. An Introduction to Contagiousness

  • a. If You Want Your Message to Spread, You Need to Get People Talking, and Imitating
  • b. The STEPPS

2. Social Currency

  • a. On the Importance of Appearances
  • b. The Appeal of the Remarkable
  • c. Manufactured Remarkability

i. Snapple
ii. Blendtec

  • d. On the Importance of Status

i. Our Accomplishments
ii. What Distinguishes Us

3. Triggers

  • a. Top of Mind, Tip of Tongue
  • b. Indirect Triggers
  • c. Natural and Artificial Triggers

i. Wassup?

  • d. When Triggers Influence Behavior

i. Mars Bars, and the Planet Mars
ii. The Effect of Music on Wine Sales
iii. Kit Kat and Coffee

  • e. Diluted Triggers

4. Emotion

  • a. Awe
  • b. Sadness
  • c. Positive and Negative Emotions
  • d. Low Arousal and High Arousal Emotions
  • e. Focusing on Emotions

i. The ‘Three Whys’
5. Public

  • a. Monkey See, Monkey Do
  • b. Solving Binge-Drinking at American Universities
  • c. The Movember Movement
  • d. Livestrong and the Yellow Wrist-Band Campaign

6. Practical Value

  • a. What’s Useful Gets Spread
  • b. Giving Advice

7. Stories

  • a. People Love Stories
  • b. Stories in Advertising: Subway
  • c. Valuable Virality

8. Conclusion

i. Introduction/Synopsis

It is only recently, with the rise of the internet, that the term ‘viral’ has gone, well, viral. But the phenomenon of social pandemics—ideas, products and behaviors, that catch on and spread quickly and widely—has been around presumably as long as sociality itself. The phenomenon is interesting in its own right, for it says something meaningful about our psychology and how we interact. However, understanding how social pandemics work also holds great practical value, for when public service messages, charity campaigns or products and services go viral, the effect has a big impact on behavior and the bottom line.

On the mechanical side of things, understanding why something goes viral is straightforward enough: it must be something that has an impact, and that people are eager to talk about or imitate. But this just forces us to ask: what is it that makes something impactful, and ripe for sharing or imitating? We may think that our intuitions can carry us some way toward answering this. Nevertheless, getting something to go viral is certainly no easy task (as many a would-be influencer has come to find); and therefore, we may benefit from a more methodical, scientifically-minded attempt to understand the phenomenon. It is just such a project that Wharton marketing professor and writer Jonah Berger has been engaged in for much of his career, and in his new book Contagious: Why Things Catch On, Berger reports on his findings.

Berger’s research has revealed that there are 6 main factors that help explain social pandemics. They are 1. Social Currency; 2. Triggers; 3. Emotion; 4. Public;  5. Practical Value; and 6. Stories

When it comes to social currency, this refers to how good or important something makes us look for sharing it. We want to look bright, funny, entertaining, knowledgeable, prestigious etc. in the eyes of others; and therefore, we are more likely to mention those things that make us appear so. Certain talking points are naturally more interesting than others, just as certain characteristics are naturally more noteworthy; however, ideas, products and behaviors can all be presented or manipulated in certain ways to allow them to partake more of each (for example, a blender may not appear so interesting, but highlighting just how powerful it is by way of having it mash-up an iPod can make it appear a whole lot more interesting—and hence more worthy of sharing).

When it comes to triggers, this refers to stimuli in the environment that are associated with other phenomena, and that remind us of them. For example, peanut butter is highly associated with jelly, and so the mention of the former often ‘triggers’ the thought of the latter. Ideas, products and behaviors that are naturally associated with triggers that we encounter more often are more likely to be brought to mind than others, thus increasing the chances that they will be both talked about and influence our behavior, and hence spread. Natural associations often work best; however, associations between unrelated items can also be established through clever advertising campaigns (such as the Kit-Kat bar being associated with a coffee break).

When it comes to emotion, this refers to the fact that phenomena that evoke highly arousing emotions, both positive and negative (such as awe, excitement, anger and anxiety), are more likely to be shared, and hence spread; while phenomena that evoke less arousing emotions (such as sadness and contentment) are less likely to be shared. The share-ability of things that evoke highly arousing emotions helps explain why Susan Boyle went viral.

When it comes to public, this refers to how prevalent something is in the public eye. Things that are highly public and visible are more likely to be talked about and imitated than those that are more private. Nevertheless, there are ways to bring private phenomena into the public sphere. For example, donating to a charity tends to be a rather private affair. However, both the Movember movement in support of colon cancer (featuring the highly conspicuous mustache), and Lance Armstrong’s Livestrong campaign in support of cancer (featuring the yellow wrist-band), managed to bring charitable support into the public sphere, thus contributing to the success of these campaigns.

Practical value refers to the fact that people like to be helpful to others, and so anything that is particularly useful is more likely to be shared than that which is less so. This helps explain why so many articles on health and education matters are so widely shared, and also why an otherwise nondescript video about shucking corn (called ‘Clean Ears Everytime’) went viral on YouTube.

When it comes to stories, this refers to the fact that people tend to enjoy telling and hearing stories. Therefore, ideas, products and behaviors that are wrapped in narratives (and especially compelling narratives) are more likely to be shared than those that are just presented as information. Google’s ‘Parisian Love’ commercial, The Dove ‘Evolution’ commercial, and Panda’s ‘Never say no to Panda’ campaign are all good examples of products being wrapped in compelling narratives.

Here is Jonah Berger introducing his new book:

What follows is a full executive summary of Contagious: Why Things Catch On by Jonah Berger.

1. An Introduction to Contagiousness

a. If You Want Your Message to Spread, You Need to Get People Talking, and Imitating

What do politicians, advertisers, charity organizations and public health officials all have in common? They all want their message to catch on and spread (loc. 322). But how to achieve this? Advertising is the immediate answer, of course. You can’t get your message to spread unless you put it out there (loc. 120). But more and more it’s becoming clear that advertising alone just isn’t enough. Even high priced and aggressive ad campaigns can fail. And that’s because just getting a message out there doesn’t mean it’s going to catch on. For that to happen, you need to get people talking, sharing and imitating (loc. 338). Social influence via word of mouth and apeing.

As Berger explains, “social influence has a huge impact on whether products, ideas, and behaviors catch on. A word-of-mouth conversation by a new customer leads to an almost $200 increase in restaurant sales. A five-star review on Amazon.com leads to approximately twenty more books sold than a one-star review. Doctors are more likely to prescribe a new drug if other doctors they know have prescribed it. People are more likely to quit smoking if their friends quit and get fatter if their friends become obese. In fact while traditional advertising is still useful, word of mouth from everyday Joes and Janes is at least ten times more effective” (loc. 151).

So, just what gets us talking and influences our behavior? This is the very question that Berger has spent much of his career investigating (loc. 307). As the author explains, “I’ve spent the last ten years, most recently as a marketing professor at the Wharton School at the University of Pennsylvania, studying this and related questions. With an incredible array of collaborators I’ve examined things like *Why certain New York Times articles or YouTube videos go viral *Why some products get more word of mouth *Why certain political messages spread *When and why certain baby names catch on or die out *When negative publicity increases, versus decreases, sales… All with the goal of understanding social influence and what drives certain things to become popular” (loc. 317).


In the course of his research, Berger and his collaborators have identified 6 factors that emerge time and again in connection with things that have managed to catch on and spread. As Berger explains, “Just as recipes often call for sugar to make something sweet, we kept finding the same ingredients in ads that went viral, news articles that were shared, or products that received lots of word of mouth. After analyzing hundreds of contagious messages, products, and ideas, we noticed that the same six ‘ingredients,’ or principles, were often at work. Six key STEPPS, as I call them, that cause things to be talked about, shared, and imitated” (loc. 351).  As mentioned in the introduction, the factors that make up these STEPPS are 1. Social Currency; 2. Triggers; 3. Emotion; 4. Public;  5. Practical Value; and 6. Stories . Let us now explore each, one by one.

2. Social Currency

a. On the Importance of Appearances

One thing that we certainly like to talk about are things that make us look good or important in the eyes of others. Being the social creatures that we are, we want to be liked and thought highly of by those around us (loc. 573), and this fact often finds its way into what we talk about. As Berger notes, “what people talk about… affects what others think of them. Telling a funny joke at a party makes people think we’re witty. Knowing all the info about last night’s big game or celebrity dance-off makes us seem cool or in the know. So, not surprisingly, people prefer sharing things that make them seem entertaining rather than boring, clever rather than dumb, and hip rather than dull” (loc. 524). Just to illustrate this last point, “we talk about how we got a reservation at the hottest restaurant in town and skip the story about how the hotel we chose faced a parking lot” (loc. 528).

*For prospective buyers: To get a good indication of how this (and other) articles look before purchasing, I’ve made several of my past articles available for free. Each of my articles follows the same form and is similar in length (15-20 pages). The free articles are available here: Free Articles

10 thoughts on “#32. A Summary of ‘Contagious: Why Things Catch On’ by Jonah Berger

  1. Hi Aaron,
    thank you very much for another great summary. Just a small comment to your reference on the Movember movement. Yes, it is men’s thing but it is actually focused on prostate cancer rather than colon cancer.

    • Thanks. I’m glad you liked the article. Also, I apologize for the error and thank you for bringing it to my attention. I have since corrected my mistake.


    • I’ve considered making videos of Cris and I discussing the books, but that’s about all. What exactly did you have in mind?


      • Just thought it would make the summaries more accessible, hopefully more popular.

        You can post the videos on amazon reviews too.

      • I think you’re right, it would be nice to feature videos. I’ll think about it…


  2. Great review, thanks! I’ve signed up to get alerts about your future reviews too. I listen to a lot of audio books on my commute, including Contagious. One of the challenges with an audio book is that it does not work well as a reference for reviewing later. Your review of this book is a perfect resource for going back over everything I tried to take in listening to the full book. Some authors are starting to provide supporting material for audio books but not nearly enough. It would be great if every time I downloaded an Audible book I also got your review. Consider talking to Audible!!! I’d gladly be a reference for you if you do. Keep up the great work.

    • Thanks Brady. I’m glad you liked the review, and it’s great to hear that it nicely accompanied the book itself. I have in fact thought of going the Audible.com route. Stay tuned…


  3. You continue to provide great value to readers like myself and happy to be a supporter of your efforts. Keep up the great work!


    • Thanks Sandeep. I’m glad to hear you’re enjoying the articles, and I’ll be happy to keep up the hard work!!


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