Twitter has a tool that lets you turn off retweets from one person at a time. But I follow thousands of people, so my office mate, who happens to be a skilled programmer, wrote a script for me that turned off retweets from everybody. Retweets make up more than a quarter of all tweets. When they disappeared, my feed had less punch-the-button outrage. Fewer mean screenshots of somebody saying precisely the wrong thing. Less repetition of big, big news. Fewer memes I’d already seen a hundred times. Less breathlessness. And more of what the people I follow were actually thinking about, reading, and doing. It’s still not perfect, but it’s much better.

This experiment got me thinking about how social platforms work. Both Twitter and Facebook rely on an ethos of sharing; both use complex algorithms to organize and rank the content you see, basing the rankings in part on how many people (in your social circles or who are similar to you) have “liked,” shared, or otherwise interacted with a post. The more people “like” something, the farther it travels.

BuzzFeed’s Jonah Peretti famously used an equation from epidemiology to illustrate the “reproduction rate” of a post: R = ßz, where z is how many people initially see the post, and ß is how likely those people are to share it—how “viral” the post is. For a story to be seen by many people, it needs a decent-size z—the seed audience—but ß is where most social-media companies have concentrated. As they’ve created algorithms to show people what they’re most likely to engage with, Twitter and Facebook have ended up promoting lots of high-ß posts.

Every layer of the digital-media economy has been reconfigured to produce shareable stuff. Writers and video makers know they need ß. Just about every high-profile, born-in-the-21st-century media company is optimized to generate viral content. Popular social-media users gain followers because they’re sensitive to the mysterious element of ß.

Over time, this emphasis on shareability has created an enormous change in what all of us, not just social-media users, see on our screens. TV-news producers look to create viral segments. Benchwarmers on NBA teams plot shareable celebrations. Companies spend millions of dollars on advertisements they hope are weird enough to go viral. To take one telling example: The senior vice president of communications at Arby’s personally brought a bag of sandwiches (and a borrowed puppy) to the creator of the spoof Twitter account @nihilist_arbys. Why? The account is high-ß. The story of the meeting was then written up by Business Insider—and that was highly shareable, too, garnering half a million page views.

But what if viral content isn’t the best content? Two Wharton professors have found that anger tops the list of shareable emotions in the social-media world, and a study of the Chinese internet service Weibo found that rage spreads faster than joy, sadness, and disgust. In general, emotional appeals work well, as everyone in media has come to discover. Fundamentally small stories that have no lasting import can dominate Twitter for days: a doctor being dragged off an airplane, the killing of Harambe the gorilla, something Lena Dunham said.