By making so much information so accessible, social media has drastically changed the way we consume information and form opinions in the modern era. The danger, however, is that social media creates an “echo chamber” that filters the information people receive so that it largely supports their existing opinions.

A recent study published in PNAS examines this phenomenon and finds that social-media users show marked focus in the types of news that interests them. These social-media participants tend to develop strong and well-defined communities around the news outlets they support, and they tend to make connections with like-minded people regardless of the geographic distance between them.

The PNAS study looked at the Facebook activity of a whopping 376 million English-speaking users. Its authors examined how these people interacted with English-speaking news sources on the platform in terms of their consumption of news, as well as their connectivity in terms of sharing, liking, and commenting on news-related items.