UNIVERSITY OF CALIFORNIA, IRVINE THE LANGUAGE OF PARTISANSHIP: A LINGUISTIC EXPLORATION OF POLITICAL BLOGS DISSERTATION submitted in partial satisfaction of tHe requirements for the degree of DOCTOR OF PHILOSOPHY in Informatics by Justin Chung THesis Committee: Professor Gloria Mark, Chair Professor Gary Olson Professor PadHraic SmytH 2015 © 2015 Justin Chung ii DEDICATION To my mom and dad. ii TABLE OF CONTENTS LIST OF FIGURES ......................................................................................................... vi LIST OF TABLES .......................................................................................................... vii ACKNOWLEDGMENTS ............................................................................................... ix CURRICULUM VITAE ................................................................................................... x ABSTRACT OF THE DISSERTATION .................................................................... xiv Chapter 1 : Introduction .................................................................................................. 1 1.1 Background ............................................................................................................ 1 1.2 Motivation .............................................................................................................. 2 1.3 Political Ideology .................................................................................................. 8 1.3.1 Ideology .......................................................................................................... 8 1.3.2 Political Partisanship in the United States ...................................................... 9 1.3.3 Political Polarization in the United States .................................................... 11 1.3.4 Public Choice Theory ................................................................................... 14 1.3.5 Moral Foundations Model ............................................................................. 16 Chapter 2 : Textual Analysis of Political Writings ...................................................... 19 2.1 Background .......................................................................................................... 19 2.1.1 Digital social research ................................................................................... 21 2.1.2 Function Words ............................................................................................. 24 2.1.3 Politics and Textual Analysis ........................................................................ 26 2.2 Research Questions .............................................................................................. 28 2.3 Dissertation Outline ............................................................................................. 32 Chapter 3 : Methods ....................................................................................................... 34 3.1 Background .......................................................................................................... 34 3.2 Data Collection .................................................................................................... 34 3.2.1 Coding ........................................................................................................... 34 3.2.2 Scraping ........................................................................................................ 36 3.2.3 Summary ....................................................................................................... 38 3.3 Data Processing .................................................................................................... 39 3.3.1 Challenges to data processing ....................................................................... 39 3.4 Analysis................................................................................................................ 41 3.4.1 LIWC ............................................................................................................ 41 3.4.2 Generalized Linear Mixed Models ............................................................... 44 3.4.3 Tools ............................................................................................................. 46 Chapter 4 : Demographics and the Language of Political Orientation ..................... 48 4.1 Introduction .......................................................................................................... 48 4.2 Ideology and Language ........................................................................................ 49 4.2 Demographics and political ideology .................................................................. 54 4.2.1 Gender ........................................................................................................... 55 4.2.2 Age ................................................................................................................ 57 4.2.3 Social class .................................................................................................... 58 iii 4.3 Demographics and Language Use ....................................................................... 60 4.4 Hypothesis............................................................................................................ 62 4.5 Methods................................................................................................................ 64 4.6 Analysis................................................................................................................ 67 4.6.1 Age ................................................................................................................ 67 4.6.2 Social Class ................................................................................................... 68 4.6.3 Gender ........................................................................................................... 69 4.6.4 Controlling for Author Gender ..................................................................... 72 4.7 Discussion ............................................................................................................ 78 4.7.1 Limitations .................................................................................................... 80 4.7.2 Alternative Explanations ............................................................................... 81 4.7.3 Language, Gender, and Politics .................................................................... 83 Chapter 5 : Linguistic Style and Political Orientation ................................................ 89 5.1 Background .......................................................................................................... 89 5.2 Linguistic Style .................................................................................................... 90 5.2.1 Political Blogs ............................................................................................. 101 5.3 Linguistic Style Matching .................................................................................. 103 5.4 Liberal and Conservative Linguistic Styles ....................................................... 106 5.5 Methods.............................................................................................................. 109 5.6 Analysis.............................................................................................................. 111 5.7 Limitations ......................................................................................................... 115 5.8 Discussion .......................................................................................................... 117 Chapter 6 : Time Series Analysis of LIWC Measures ............................................... 123 6.1 Introduction ........................................................................................................ 123 6.1.1 Analysis of literary style ............................................................................. 123 6.1.2 Style and temporal factors .......................................................................... 126 6.2 Research Questions and Approach .................................................................... 129 6.2.1 Approach ..................................................................................................... 132 6.3 Methods.............................................................................................................. 135 6.3.1 Data Smoothing .......................................................................................... 137 6.3.2 Cross-Correlation Functions ....................................................................... 138 6.4 Results ................................................................................................................ 139 6.4.1 Function words............................................................................................ 140 6.4.2 Assent .......................................................................................................... 157 6.5 Discussion .......................................................................................................... 159 6.5.1 Smoothing ................................................................................................... 162 6.5.2 Interdependence .......................................................................................... 163 6.5.3