51�Թ���

On Feb. 11, 2020, the World Health Organization put a name to the mysterious respiratory disease spreading with alarming speed around the globe: COVID-19.

Around the same time, two of the internet’s most popular communities for discussing this unfolding crisis began to drift apart—with one increasingly embracing racist language and conspiracy theories, while the other tended to avoid those topics.��

Now, researchers at the 51�Թ��� are exploring this tale of two online communities: the and discussion boards on the social media site Reddit.

Click to expand: Screenshots of activity on the r/China_flu community.

In a , the 51�Թ��� group discovered that some content moderation may go a long way.

After the r/Coronavirus subreddit began to enforce a set of rules around what users could and couldn’t post, some more radical Redditors seemed to drift to r/China_flu—where false information about the virus and anti-Asian sentiment became more common.

“We saw these two communities go in different directions,” said Jason Shuo Zhang, a graduate student in the Department of Computer Science and lead author of the new study.

The study, which is currently under peer review, comes at a time when many internet platforms are struggling to crack down on hate speech. On June 29, 2020, from its site, including one of the biggest platforms for supporters of President Donald Trump, r/The_Donald—a case study in how social media sites have become what study coauthor Brian Keegan calls “laboratories for democracy.”

“You’re seeing these online communities explore what works and what doesn’t work when it comes to different ways of doing governance,” said Keegan, an assistant professor in the Department of Information Science.��

The pandemic’s path

Keegan’s previous research has delved into how online communities reflect events in the world, including the He also coauthored a study examining the content used in 16 million comments on r/The_Donald.

“These breaking news events are opportunities to see how emergent social interactions coalesce into coherent and stable social structures,” he said.

He and his colleagues turned to Reddit to follow that process in real time. The site hosts more than 100,000 “subreddits” that give users a chance to post memes and news about their favorite topics from NBA teams to the collapse of human civilization. ��

As of June, two of Reddit’s most popular communities for discussing COVID-19 were r/Coronavirus, which boasted 2.2 million members, and r/China_flu, which had 112,000. In all, the group analyzed the language used in 312,000 posts and 7 million comments written in English on both sites from January through May 2020.

At the start of the outbreak, Zhang said, the content on the two subreddits didn’t differ much. Then on Feb.��17, that changed.

On that day, Reddit made r/Coronavirus the site’s official platform for all COVID-19 talk. Moderators on the platform also began to more carefully scrub information deemed to violate community rules, including potentially misleading public health guidance. r/China_flu moderators, in contrast, took��a less hands-on approach to comments.

“We observed this shift in policy when the platform decided to make r/Coronavirus the official subreddit, while more relaxed discussions could take place in r/China_flu,” Zhang said.��

As of May 18, only 5% of active members on r/Coronavirus also posted content to r/China_flu, down from more than 30% in mid-February.��

Word usage followed suit. At the end of March, r/Coronavirus members disproportionately used more neutral terms like “groceries” or “tests” in their comments. r/China_flu users, in contrast, more heavily relied on words like “communist,” “bat” and “lab”—perhaps a reference to a common conspiracy theory that the coronavirus had been designed in a lab in Wuhan, China.��

“When we go deep and compare their language usage, we find that r/China_flu users pay much more attention to China-related topics and have higher overlaps with other extreme communities on the Reddit platform,” Zhang said.

Online and offline

The case of the two subreddits shows how people’s offline life can spill into the online world—and vice-versa, said study coauthor Chenhao Tan, an assistant professor of computer science at 51�Թ���. The team found, for example, that the user activity on subreddits related to sports and travel plummeted in spring 2020.

“Far from being only online, social media has become deeply connected with everything we do offline,” Tan said.��

He and Keegan also recently responded to the pandemic. Wikipedia employs more aggressive strategies than Reddit to limit the participation of users engaged in bad behavior—and those strategies were reflected in the site’s largely accurate and timely health content.

Tan added that it’s too early to say whether strong content moderation should become the norm for the internet during times of crisis—when falsehoods can run rampant��on social media. But the study provides a deep look at a unique time in the history of human social interactions.��

“I think social media and Reddit provide a window into this period where people had to be in front of a computer or on their cellphones,” he said.��

The Reddit study also included coauthor Qin (Christine) Lv, an associate professor of computer science.