They also want structural changes that aim to prevent the spread of fake news, calling for an interdisciplinary research effort that involves various social media platforms.
"And on social networks, people can gain attention by being the first to share previously unknown (but possibly false) information".
If it seems like fake news is everywhere, that may be because it is. While the bots tweeted false information at a higher rate than humans, it wasn't that much of a difference, and even without bots, lies still spread faster and farther, Roy said.
According the biggest study to date into fake news, the truth takes six times longer to be seen by 1,500 people on Twitter than misinformation.
The study, highlighted this week in The Atlantic, surveyed the spread of 126,000 news stories, including both true accounts and false "rumor cascades", on Twitter between September 2006 and December 2016.
A study of 126,000 rumours and false news stories spread on Twitter over a period of 11 years found that they travelled faster and reached more people than the truth. And falsehoods are retweeted by unique users more broadly than true statements at every depth of cascade. They also used a broad definition of "news".
The researchers examined this "novelty hypothesis" in their research by taking a random subsample of Twitter users who propagated false stories, and analysing the content of the reactions to those stories.
The six fact-checking websites agreed with each other on classification at least 95 percent of the time, plus two outside researchers did some independent fact-checking to make sure everything was OK, said co-author Sinan Aral, an MIT management professor.
"The more odd and more sensational the story sounds, the more likely they are going to retweet", Kahan said. "[False] news spreads farther, faster, deeper, and more broadly than the truth because humans, not robots, are more likely to spread it". "Thus, people who share novel information are seen as being in the know", Aral said.
But don't forget about the bots, argue Filippo Menczer of Indiana University and colleagues.
The researchers looked at obvious bots - automated accounts - and took them out.
The term "fake news" has in recent times become part of the lexicon of many people, thanks in part to US President Donald Trump regularly using it - often when referring to reports that are accurate but critical of him or his administration.
Why do people fall for it, whether it's from a bot or a real friend?
"False news is more novel, and people are more likely to share novel information", Aral added, explaining why people tend to share more false news. Plus, people like to repeat information that seems to affirm their beliefs.
And fact-checking can backfire, they noted.
The indictment of 13 Russians in the operation of a "troll farm" that spread false information related to the 2016 USA presidential election has renewed the spotlight on the power of "fake news" to influence public opinion.
Intelligence agencies in the U.S. have accused Russian Federation of helping spread fake news stories during the 2016 United States presidential election with a view to helping Trump get elected, something the country has denied.