Slanted media outlets are often blamed for growing polarization, but new research points to another consequence of consuming partisan news: an erosion of trust in the media.

A team of researchers combined computational social science techniques and experimentation to study the long-term effects of online partisan media on political opinions and trust.

Internet users were asked to change their default browser homepages to either the Huffington Post, a left-leaning news site, or Fox News, a more conservative outlet, during the 2018 U.S. midterm elections. As participants went about their daily activities, they allowed the researchers to survey them multiple times as well as to collect data on millions of web visits and their posts on Twitter.

After eight weeks, the participants’ trust in the media appeared to decrease, and this effect remained detectable nearly a year later for visitors to both partisan news sites. Increased exposure to partisan news led to an immediate — though short-lived — boost in the number of visits to both sites, as well as improved knowledge of recent events. However, these effects did not appear to translate to changes in political attitudes, opinions, or behaviors.