Ana Lucía Schmidt1, Fabiana Zollo2, Antonio Scala3, Cornelia Betsch4, Walter Quattrociocchi5. 1. Ca' Foscari University of Venice, Via Torino 155, 30172 Venice, Italy. Electronic address: analucia.schmidt@unive.it. 2. Ca' Foscari University of Venice, Via Torino 155, 30172 Venice, Italy. Electronic address: fabiana.zollo@unive.it. 3. ISC-CNR, SC-CNR, Sapienza University of Rome, Via dei Taurini 19, 00185 Rome, Italy. Electronic address: antonio.scala@phys.uniroma1.it. 4. University of Erfurt, Nordhäuserstr, 63, 9089 Erfurt, Germany. Electronic address: cornelia.betsch@uni-erfurt.de. 5. Ca' Foscari University of Venice, Via Torino 155, 30172 Venice, Italy. Electronic address: w.quattrociocchi@unive.it.
Abstract
BACKGROUND: Vaccine hesitancy has been recognized as a major global health threat. Having access to any type of information in social media has been suggested as a potential influence on the growth of anti-vaccination groups. Recent studies w.r.t. other topics than vaccination show that access to a wide amount of content through the Internet without intermediaries resolved into major segregation of the users in polarized groups. Users select information adhering to theirs system of beliefs and tend to ignore dissenting information. OBJECTIVES: The goal was to assess whether users' attitudes are polarized on the topic of vaccination on Facebook and how this polarization develops over time. METHODS: We perform a thorough quantitative analysis by studying the interaction of 2.6 M users with 298,018 Facebook posts over a time span of seven years and 5 months. We applied community detection algorithms to automatically detect the emergence of communities accounting for the users' activity on the pages. Also, we quantified the cohesiveness of these communities over time. RESULTS: Our findings show that the consumption of content about vaccines is dominated by the echo chamber effect and that polarization increased over the years. Well-segregated communities emerge from the users' consumption habits i.e., the majority of users consume information in favor or against vaccines, not both. CONCLUSION: The existence of echo chambers may explain why social-media campaigns that provide accurate information have limited reach and be effective only in sub-groups, even fomenting further opinion polarization. The introduction of dissenting information into a sub-group is disregarded and can produce a backfire effect, thus reinforcing the pre-existing opinions within the sub-group. Public health professionals should try to understand the contents of these echo chambers, for example by getting passively involved in such groups. Only then it will be possible to find effective ways of countering anti-vaccination thinking.
BACKGROUND: Vaccine hesitancy has been recognized as a major global health threat. Having access to any type of information in social media has been suggested as a potential influence on the growth of anti-vaccination groups. Recent studies w.r.t. other topics than vaccination show that access to a wide amount of content through the Internet without intermediaries resolved into major segregation of the users in polarized groups. Users select information adhering to theirs system of beliefs and tend to ignore dissenting information. OBJECTIVES: The goal was to assess whether users' attitudes are polarized on the topic of vaccination on Facebook and how this polarization develops over time. METHODS: We perform a thorough quantitative analysis by studying the interaction of 2.6 M users with 298,018 Facebook posts over a time span of seven years and 5 months. We applied community detection algorithms to automatically detect the emergence of communities accounting for the users' activity on the pages. Also, we quantified the cohesiveness of these communities over time. RESULTS: Our findings show that the consumption of content about vaccines is dominated by the echo chamber effect and that polarization increased over the years. Well-segregated communities emerge from the users' consumption habits i.e., the majority of users consume information in favor or against vaccines, not both. CONCLUSION: The existence of echo chambers may explain why social-media campaigns that provide accurate information have limited reach and be effective only in sub-groups, even fomenting further opinion polarization. The introduction of dissenting information into a sub-group is disregarded and can produce a backfire effect, thus reinforcing the pre-existing opinions within the sub-group. Public health professionals should try to understand the contents of these echo chambers, for example by getting passively involved in such groups. Only then it will be possible to find effective ways of countering anti-vaccination thinking.
Authors: Young Anna Argyris; Kafui Monu; Pang-Ning Tan; Colton Aarts; Fan Jiang; Kaleigh Anne Wiseley Journal: JMIR Public Health Surveill Date: 2021-06-24