Social Media, News Consumption, and Polarization: Evidence from a Field Experiment

Facebook's algorithm at present appears to produce echo chambers in which people are less likely to see counterattitudinal content.

“Facebook’s algorithm at present appears to produce echo chambers in which people are less likely to see counterattitudinal content (Levy, 2021).”

It is neither clear what level of homophily in social networks is desirable or undesirable in a democratic society, nor clear how to interpret results of certain studies on polarization whose findings depend on whether one assumes social media increased or decreased exposure to opposing views relative to an offline benchmark.

“For instance, it is neither clear what level of homophily in social networks is desirable or undesirable in a democratic society, nor is it clear how to interpret the results of certain studies on polarization69,130, whose findings depend on whether one assumes that social media have increased or decreased exposure to opposing views relative to some offline benchmark.”

If exposure to opposing views is increased on social media, the conclusion of one study would be that it reduces polarization, but if exposure is decreased, one would come to the opposite conclusion.

“For example, if exposure to opposing views is increased on social media, the conclusion of one study130 would be that it reduces polarization, but if exposure is decreased, one would come to the opposite conclusion.”

In another experiment, thousands of Facebook users were randomly assigned to subscribe to liberal or conservative news outlets for at least two weeks; results confirmed that Facebook's algorithm limits exposure to counter-attitudinal news in general, but when participants were assigned to receive counter-attitudinal news they were willing to read and share it.

“In another experiment, thousands of Facebook users were randomly assigned to subscribe to liberal or conservative news outlets for at least two weeks259. Results of the study confirmed that Facebook’s algorithm limits exposure to counter-attitudinal news in general, but when participants were assigned to receive counter-attitudinal news they were willing to read and share it.”

Large-scale field experiments aimed at reducing polarization by intervening on the feed algorithm have found both a decrease and an increase in polarization.

“However, large-scale field experiments aimed at reducing polarization by intervening on the feed algorithm-for example, by increasing exposure to out-party content-have found both a decrease (35) and an increase (36) in polarization.”

In social networks, maximizing user engagement may be achieved by promoting content congruent with users' past engagement or ingroup attitudes, or content that humans inherently attend to, such as emotionally and morally charged content.

“In social networks, this may be achieved by promoting content congruent with users' past engagement or ingroup attitudes 134 , or content that humans inherently attend to, such as emotionally and morally charged content 135,136 .”