Title: Exposure to opposing views on social media can increase political polarization | PNAS
Headings: Exposure to opposing views on social media can increase political polarization
Research Article
Exposure to opposing views on social media can increase political polarization
Significance
Abstract
Research Design
Results
Discussion and Conclusion
Materials and Methods
Acknowledgments
Footnotes
References

Content: These partisan divisions not only impede compromise in the design and implementation of social policies but also have far-reaching consequences for the effective function of democracy more broadly ( 11 ⇓⇓⇓ – 15 ). America’s cavernous partisan divides are often attributed to “echo chambers,” or patterns of information sharing that reinforce preexisting political beliefs by limiting exposure to opposing political views ( 16 ⇓⇓⇓ – 20 ). Concern about selective exposure to information and political polarization has increased in the age of social media ( 16, 21 ⇓ – 23 ). The vast majority of Americans now visit a social media site at least once each day, and a rapidly growing number of them list social media as their primary source of news ( 24 ). Despite initial optimism that social media might enable people to consume more heterogeneous sources of information about current events, there is growing concern that such forums exacerbate political polarization because of social network homophily, or the well-documented tendency of people to form social network ties to those who are similar to themselves ( 25, 26 ). The endogenous relationship between social network formation and political attitudes also creates formidable challenges for the study of social media echo chambers and political polarization, since it is notoriously difficult to establish whether social media networks shape political opinions, or vice versa ( 27 ⇓ – 29 ). Here, we report the results of a large field experiment designed to examine whether disrupting selective exposure to partisan information among Twitter users shapes their political attitudes. Our research is governed by three preregistered hypotheses. The first hypothesis is that disrupting selective exposure to partisan information will decrease political polarization because of intergroup contact effects. A vast literature indicates contact between opposing groups can challenge stereotypes that develop in the absence of positive interactions between them ( 30 ).