Why Do Things Go Viral?

When something “goes viral,” it spreads to an enormous number of people online at lightning speed. Here is how it works: Someone posts a video on, say, YouTube. Other people like it and share it with their friends. Then those friends share it, and so on.

The phenomenon of going viral is relatively new. When your grandparents and even your parents were kids, people relied on newspapers, TV shows, magazines, or word of mouth to hear about things. That meant it could take a while for something to catch on—whether a fashion trend or a new dance.

It was not until the internet came along in the 1990s that everything began to change. For the first time, content could be shared with just a click—and that content could quickly reach people all over the world. By the early 2000s, social media had arrived, and content spread even faster. One of the first viral videos was “David After Dentist,” in 2009. The video showed a kid acting a bit loopy after getting a tooth pulled. His dad posted the video on YouTube on a Friday. By Sunday, it had more than 10,000 views. By Wednesday, it had 4 million. Soon, it was everywhere.

Today, going viral is not only possible, it’s also common. It seems something new is trending every day. Still, most posts don’t get much attention. Some are barely seen at all. So what is it about those mega-popular posts that sets them apart?

A lot of it comes down to emotion. We are more likely to share something that makes us feel positive emotions.* This explains why viral videos often make us laugh, smile, or gush with love. But in fact, anything that evokes strong feelings is more likely to go viral—even if those feelings are negative.

“It’s not just whether emotions are positive or negative but whether they fire us up to take action,” explains Jonah Berger, a professor at the University of Pennsylvania and author of Contagious: Why Things Catch On. “Things that fire us up lead us to share.”

We’re also inspired to share information that’s new. Humans are naturally curious, and we’re intrigued by content that teaches us something. Plus, it’s human nature to want to be seen as “in the know,” so if we see something new—whether it’s a baked feta pasta recipe or breaking news about a celebrity—we tend to share it quickly. The same goes for content that feels useful (think #lifehacks) or that’s easy to imitate (think TikTok dances).

But going viral isn’t only about how content makes us feel. It also has to do with something called an algorithm. An algorithm is a set of instructions that tell a computer what to do. Social media platforms all use algorithms to organize the content that people post. The main goal of these algorithms is to serve users with the posts that they most likely want to see and interact with.

For example, the “For You” page on TikTok is run by an algorithm. It analyzes what kinds of videos you’ve liked, commented on, or watched. If you often interact with cat videos, the algorithm is going to fill your “For You” page with cat videos.

On many platforms, content made by a person with a large following is pushed to the top of feeds. That’s because the algorithm “knows” that person creates posts lots of users want to see. This also means it can be even harder for people with small followings to get their content to go viral—even if that content is clever or creative or meaningful.

In this way, algorithms essentially control what we all see on social media.

So if you’ve ever created a video or meme that hasn’t racked up lots of likes or shares, it doesn’t mean it wasn’t special. And does it really matter how many likes or views we get anyway? Social media started out as a space for people to connect with each other, to be creative, to have fun. So maybe we should be measuring our success by how much we laughed while trying to create a TikTok dance or whether we put a smile on a friend’s face.

In other words, perhaps in the end what really matters isn’t going viral at all.

_{* “What Makes Online Content Viral?” by Jonah Berger and Katherine L . Milkman, Journal of Marketing Research, 2011}

^{This article was originally published in the March 2022 issue.}