In recent weeks, the amount of online fake news that circulated during the final months of the presidential race is coming to light, a disturbing revelation that threatens to undermine the country’s democratic process. We’re already seeing some real-world consequences. After fake news stories implicated a Washington, D.C. pizza shop as the site of a Clinton-coordinated child sex ring, a man wielding an AR-15 assault rifle entered the store on Dec. 4 to “investigate” and fired shots.



Much of the analysis, however, has focused on the people who create these false articles – whether it’s teenagers in Macedonia or satirical news sites – and what Facebook and Google can do to prevent its dissemination.

But fake news wouldn’t be a problem if people didn’t fall for it and share it. Unless we understand the psychology of online news consumption, we won’t be able to find a cure for what The New York Times calls a “digital virus.”

Some have said that confirmation bias is the root of the problem – the idea that we selectively seek out information that confirms our beliefs, truth be damned. But this doesn’t explain why we fall for fake news about nonpartisan issues.

A more plausible explanation is our relative inattention to the credibility of the news source. I’ve been studying the psychology of online news consumption for over two decades, and one striking finding across several experiments is that online news readers don’t seem to really care about the importance of journalistic sourcing—what we in academia refer to as “professional gatekeeping.” This laissez-faire attitude, together with the difficulty of discerning online news sources, is at the root of why so many believe fake news.