A new study by three MIT scholars has found that false news spreads more rapidly on Twitter than real news does—and by a substantial margin.

“We found that falsehood diffuses significantly farther, faster, deeper, and more broadly than the truth, in all categories of information, and in many cases by an order of magnitude,” says Sinan Aral, a professor at the MIT Sloan School of Management and coauthor of a paper detailing the results in Science.

“These findings shed new light on fundamental aspects of our online communication ecosystem,” says study coauthor Deb Roy, an associate professor of media arts and sciences at the MIT Media Lab and director of the Media Lab’s Laboratory for Social Machines (LSM). Roy, who served as Twitter’s chief media scientist from 2013 to 2017, adds that the researchers were “somewhere between surprised and stunned” at the different trajectories of true and false news on Twitter.

To conduct the study, the researchers tracked roughly 126,000 “cascades,” or unbroken retweet chains, of news stories cumulatively tweeted over 4.5 million times by about three million people from 2006 to 2017. To determine whether stories were true or false, they used the assessments of six fact-checking organizations.

The researchers found that false news stories are 70 percent more likely to be retweeted than true stories are. It also takes true stories about six times as long to reach 1,500 people as it does for false stories to reach the same number of people. And falsehoods reach a “cascade depth” of 10 about 20 times faster than real facts do.

Moreover, the scholars found, bots are not the principal reason inaccurate stories get around so much faster and farther than real news is able to manage. Instead, inaccurate news items spread faster around Twitter because people are retweeting them.

“When we removed all of the bots in our data set, [the] differences between the spread of false and true news stood,” says LSM postdoc and paper coauthor Soroush Vosoughi, whose PhD research with Roy on the spread of rumors led to the current study.

So why do falsehoods spread more quickly than the truth on Twitter? The scholars suggest the answer may reside in human psychology: we like new things, and false news is often accompanied by reactions of surprise.

“False news is more novel, and people are more likely to share novel information,” Aral says.