6 MIT News May/June 2018 www.technologyreview.com
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False news flies faster
On Twitter, falsehoods spread more quickly than the truth.
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
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
“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 accom-
panied by reactions of surprise.
“False news is more novel, and people are more likely to share
novel information,” Aral says. —Peter Dizikes S A