Monitoring and Expressing Opinions on Social Networking Sites – Empirical Investigations based on the Spiral of Silence Theory Von der Fakultät für Ingenieurwissenschaften, Abteilung Informatik und Angewandte Kognitionswissenschaft der Universität Duisburg-Essen zur Erlangung des akademischen Grades Doktor der Philosophie (Dr. phil.) genehmigte Dissertation von German Neubaum aus Buenos Aires, Argentinien 1. Gutachterin: Prof. Dr. Nicole Krämer 2. Gutachter: Prof. Dr. Joseph Walther Tag der mündlichen Prüfung: 12. Mai 2016 3 Acknowledgments The present thesis is dedicated to all those who have accompanied and enriched my (PhD) journey during the last three and a half years. This journey has been full of ups and downs, joy and frustration, and without the professional and personal support of many people I would not have survived it so well. During my journey I was lucky enough to have two “doctoral parents” who guided my way, encouraged me to keep on going, and inspired me with their knowledge and devotion to empirical research. First, I would like to express my gratitude to my advisor Nicole Krämer, who supported and fostered my curiosity in psychological and communication research from the start. The “Krämer School” has taught me how to develop and pursue my own research ideas and questions, how to manage seemingly unmanageable challenges, and how to continuously believe in positive outcomes. Nicole, thank you for opening so many doors for me. I am sure that I will benefit from your advice and guidance throughout my professional career. Second, I wish to thank my second mentor, Joseph Walther, who made great efforts to enable me to visit and work with him in Singapore. I am so grateful that I had the chance to visit the “Walther School,” which substantially expanded my ways of thinking, teaching me how to critically question theoretical ideas and empirical approaches, and how to find joy in this scrutiny. Joe, thank you for your generosity in taking so much time to teach me these things and much more. Stephan Winter, thank you for the highest level of entertainment in and outside our office, enlightening discussions, sage advice, and for all the time and effort you invested in giving constructive feedback on this work. Our LE243 discussions and shared fascination for research have significantly inspired the present dissertation. Thank you, Laura Hoffmann and Leonie Rösner, for being my “doctoral sisters” sharing all the ups and downs of our journeys and for mutual encouragement. I also wish to thank Sabrina Eimler, Sabrina Sobieraj, and Tina Ganster for the pizzas, the parties, and the laughter as well as all past and current members of the social psychology family at the University of Duisburg-Essen for giving me such an enjoyable and instructive time. On the other side of the world, I want to express my gratitude to all those who accompanied my time at the Wee Kim Wee School of Communication and Information at the Nanyang Technological University in Asia’s Disneyland Singapore. Thank you, Shirley Ho, for sharing the enthusiasm for the spiral of silence theory and for collaborating with me in this exciting field. During my visit in Singapore, I learnt so much, not only about research but also about a new culture and different 4 ways of thinking and living, leading me to learn more about myself. A special thanks to the German Academic Exchange Service for making this learning experience possible. Outside the scientific world, there are so many people to whom I am indebted. First, I would like to thank my parents, Nora and Daniel, who have made incredible sacrifices to enable my sister and me to grow up in an environment where education is highly valued. Your selflessness combined with your strength, wisdom, and unconventional thinking make me so proud to be your son. Thank you for giving me so much without asking for anything in return. Thanks to my sister, Magdalena, for paving the way in so many respects and for believing in me. Furthermore, I wish to thank Rita, Anja, and in loving memory Volkmar for letting me be part of the family and for being there whenever needed. We made it through the darkest days and I learnt so much from your positivity. Thank you for encouraging and supporting me tirelessly! This work would not have been possible without living moments of lightheartedness. Martin, Laura, Ina, Lisa, Marius, Tina, Daniel P., Tessi, Jules, and Daniel N., thank you for being the craziest buddies and true companions – you always make light of any situation. Each and every one of you contributed to this work in his/her own way. Finally, I would like to thank my most significant other, Kathrin. From day one on, you have empowered me to undertake this adventure, knowing that it would require many compromises. But you taught me what really counts in life. Thank you for being my best friend and accompanying every single step of this journey, the easy and the tough ones, with boundless affection. Your contagious optimism and unconditional support made finishing this work possible. Now, I can’t wait to start a new chapter in our lives! 5 Parts of this dissertation have been presented in or accepted for talks and posters at conferences or have been published in peer-reviewed journals. Please refer to the following publications for more information: Study 1 Neubaum, G., & Krämer, N. C. (2015, September). Monitoring the opinion of the crowd – Psychological patterns of public opinion perceptions in social media. Paper presented at the 9th Conference of the Media Psychology Division of the DGPs (German Psychological Society), Tübingen, Germany. Neubaum, G. (2016, June). Monitoring the opinion of the crowd: Media and social psychological mechanisms underlying public opinion perceptions on social media. Paper presented at the annual meeting of ICA 2016 (International Communication Association), Fukuoka, Japan. Neubaum, G., & Krämer, N. C. (2016). Monitoring the opinion of the crowd: Psychological mechanisms underlying public opinion perceptions on social media. Media Psychology. Advance online publication. doi:10.1080/15213269.2016.1211539 Studies 2 & 3 Neubaum, G. (2015, May). What do we fear of? Expected sanctions for expressing minority opinions in offline and online communication. Paper presented at the annual meeting of ICA 2015 (International Communication Association), San Juan, Puerto Rico. Neubaum, G., & Krämer, N. C. (2016). What do we fear? Expected sanctions for expressing minority opinions in offline and online communication. Communication Research. Advance online publication. doi:10.1177/0093650215623837 Study 4 Neubaum, G., Ho, S. S., & Krämer, N. C. (2016, January). Der Öffentlichkeitseffekt: Wie der Grad der Öffentlichkeit auf sozialen Medien die Redebereitschaft beeinflusst [The publicness effect: How the level of publicness in social media influences the willingness to speak out]. Paper presented at the annual conference of the Audience and Reception Studies Division of the German Communication Association (DGPuK), Amsterdam, Netherlands. Neubaum, G., & Ho, S. S. (2016, June). For all eyes to see: A cross-cultural comparison of the effect of publicness on opinion expression in social media. Paper presented at the annual meeting of ICA 2016 (International Communication Association), Fukuoka, Japan. Study 5 Neubaum, G., (2015, July). How different audiences in social media affect people’s outspokenness on controversial issues. Poster presented at the international summer school “Living with Media” at the University of Cologne, Germany. 7 TABLE OF CONTENTS List of Tables ........................................................................................................................................ 10 List of Figures ...................................................................................................................................... 12 Abstract ................................................................................................................................................ 13 Zusammenfassung ............................................................................................................................... 15 I INTRODUCTION ............................................................................................................................ 17 II THEORETICAL FRAMEWORK ................................................................................................ 20 1 The Informational and Discursive Use of the Internet ............................................................. 20 1.1 Early Years of the Internet as a Forum for Public Deliberation .............................................. 20 1.2 Characterizing Social Media as a Venue for Information and Discussion .............................. 25 1.2.1 Social Media as a Source of Political and Societal Information ...................................... 29 1.2.2 Social Media as a Venue for the Exchange of Opinions .................................................. 32 2 The Formation of Public Opinion: A Social Psychological View ............................................. 37 2.1 Conceptualizations of Public Opinion ..................................................................................... 37 2.2 Pioneering Research on Social Influence Processes ................................................................ 41 2.3 The Spiral of Silence Theory ................................................................................................... 48 2.3.1 Theoretical Propositions and Empirical