On social media, encountering opposing views can make people become even more wedded to their own.
During his appearance before Congress on Wednesday, Twitter’s chief executive, Jack Dorsey, repeatedly denied that Twitter’s algorithms are biased against conservative voices. His denials echoed recent statements he has made about the importance of exposing people to opposing political views. Indeed, he announced last month that Twitter was experimenting with new features that would actively expose people to such views.
The link between social media and political polarization, however, presents a classic chicken-or-egg question: Do the accounts we follow on platforms such as Twitter shape our political views, or do we mostly follow accounts that reflect our views? We cannot know whether social media is a cause or a symptom of our deeply divided politics, unless, of course, we conduct a controlled experiment.
In a study that was published last month in the journal Proceedings of the National Academy of Sciences, my colleagues and I did just that. We surveyed more than 1,200 Twitter-using Republicans and Democrats about their political views. Then we paid half of them to follow for one month a bot we created that retweeted messages from elected officials and other opinion leaders from the other political party.
Instead of reducing political polarization, being exposed to opposing ideas increased it. Republicans who followed a Democratic bot for one month expressed social policy views that were substantially more conservative at the conclusion of the study. Democrats who followed a Republican bot exhibited very slight increases in liberal attitudes about social issues, but those effects were not statistically significant.