title: The spreading of misinformation online.
abstract: The wide availability of user-provided content in online social media facilitates the aggregation of people around common interests, worldviews, and narratives. However, the World Wide Web (WWW) also allows for the rapid dissemination of unsubstantiated rumors and conspiracy theories that often elicit rapid, large, but naive social responses such as the recent case of Jade Helm 15--where a simple military exercise turned out to be perceived as the beginning of a new civil war in the United States. In this work, we address the determinants governing misinformation spreading through a thorough quantitative analysis. In particular, we focus on how Facebook users consume information related to two distinct narratives: scientific and conspiracy news. We find that, although consumers of scientific and conspiracy stories present similar consumption patterns with respect to content, cascade dynamics differ. Selective exposure to content is the primary driver of content diffusion and generates the formation of homogeneous clusters, i.e., "echo chambers." Indeed, homogeneity appears to be the primary driver for the diffusion of contents and each echo chamber has its own cascade dynamics. Finally, we introduce a data-driven percolation model mimicking rumor spreading and we show that homogeneity and polarization are the main determinants for predicting cascades' size.
authors.affiliation: Laboratory of Computational Social Science, Networks Department, IMT Alti Studi Lucca, 55100 Lucca, Italy;
authors.forename: Michela
authors.initials: M
authors.lastname: Del Vicario
authors.affiliation: IUSS Institute for Advanced Study, 27100 Pavia, Italy;
authors.forename: Alessandro
authors.initials: A
authors.lastname: Bessi
authors.affiliation: Laboratory of Computational Social Science, Networks Department, IMT Alti Studi Lucca, 55100 Lucca, Italy;
authors.forename: Fabiana
authors.initials: F
authors.lastname: Zollo
authors.affiliation: Sapienza University, 00185 Rome, Italy;
authors.forename: Fabio
authors.initials: F
authors.lastname: Petroni
authors.affiliation: Laboratory of Computational Social Science, Networks Department, IMT Alti Studi Lucca, 55100 Lucca, Italy; ISC-CNR Uos "Sapienza," 00185 Rome, Italy;
authors.forename: Antonio
authors.identifier: http://orcid.org/0000-0002-3414-2686
authors.initials: A
authors.lastname: Scala
authors.affiliation: Laboratory of Computational Social Science, Networks Department, IMT Alti Studi Lucca, 55100 Lucca, Italy; ISC-CNR Uos "Sapienza," 00185 Rome, Italy;
authors.forename: Guido
authors.initials: G
authors.lastname: Caldarelli
authors.affiliation: Boston University, Boston, MA 02115.
authors.forename: H Eugene
authors.initials: HE
authors.lastname: Stanley
authors.affiliation: Laboratory of Computational Social Science, Networks Department, IMT Alti Studi Lucca, 55100 Lucca, Italy; walterquattrociocchi@gmail.com.
authors.forename: Walter
authors.initials: W
authors.lastname: Quattrociocchi
mesh_terms: D003142:Communication; D003198:Computer Simulation; D006801:Humans; D008962:Models, Theoretical; D012586:Science; D061108:Social Media
keywords: Facebook; cascades; misinformation; rumor spreading; virality