INFORMAL REASONING WITH AND WITHOUT THE INTERNET: AN INDIVIDUAL DIFFERENCES APPROACH A Dissertation Presented to The Academic Faculty By Victor J. Ellingsen In Partial Fulfillment Of the Requirements for the Degree Doctor of Philosophy in Psychology Georgia Institute of Technology May, 2017 Copyright © 2017 by Victor J. Ellingsen Informal Reasoning With and Without the Internet: An Individual Differences Approach Approved by: Dr. Phillip L. Ackerman, Advisor Dr. Rick P. Thomas School of Psychology School of Psychology Georgia Institute of Technology Georgia Institute of Technology Dr. Margaret E. Beier Dr. Paul Verhaeghen Department of Psychology School of Psychology Rice University Georgia Institute of Technology Dr. James S. Roberts School of Psychology Date Approved: March 29, 2017 Georgia Institute of Technology ACKNOWLEDGEMENTS I would like to thank my advisor, Dr. Phillip Ackerman, for his guidance on this project and over the course of my graduate school career. I also appreciate the advice provided by the other committee members during this project. I also would like to thank the many people whose support was perhaps less tangible, but just as important. Erin Marie Conklin, Samuel Posnock, and Charles Calderwood provided invaluable insight into how to follow in their footsteps. Elnora Kelly, Laura Barg-Walkow, Sadaf Kazi, Chelsea Vance, Mike Morrison, and Ilya Gokhman were with me to celebrate the highs and commiserate on the lows that are inevitably part of graduate school. Franklin Rea, Kyle Jones, and my exceptionally patient mother were always willing to listen despite not always knowing what I was talking about or why it seemed important. The many friends I met through Georgia Tech Hapkido and Black Knight Martial Arts were a wonderful and much-needed community outside of the lab. In particular, Dr. Brian Ritchie and Dr. Matthieu Bloch generously offered their views of grad school from the “other side,” which helped me keep things in perspective. I am also indebted to the 2017 federal hiring freeze, which left me with nothing to do for three months except to sit in New Hampshire and finish this dissertation. Finally, this project would not have been possible without assistance from Chelsea Vance, Andrew Helbling, Soundarya Kanthimathinathan, and Sadaf Kazi, who helped code the more than 10,000 arguments generated by participants in these two studies. iii TABLE OF CONTENTS ACKNOWLEDGEMENTS ............................................................................................... iii LIST OF TABLES ............................................................................................................. vi SUMMARY ..................................................................................................................... viii CHAPTER 1 ....................................................................................................................... 1 Measurement Approaches ............................................................................................... 5 Prompt types ................................................................................................................ 5 Tasks ............................................................................................................................ 8 Instructions .................................................................................................................... 15 Interim Summary and Theoretical Framework ............................................................. 16 Individual Differences in Informal Reasoning .............................................................. 19 Within-person consistency of informal reasoning performance ................................ 19 Cognitive ability ........................................................................................................ 20 Prior knowledge ......................................................................................................... 23 Prior opinion .............................................................................................................. 26 Non-ability factors ..................................................................................................... 28 Program of Research ..................................................................................................... 30 Study 1 ....................................................................................................................... 30 Study 2 ....................................................................................................................... 31 Interim Summary and Overview of Method ................................................................. 41 CHAPTER 2 ..................................................................................................................... 42 Method .......................................................................................................................... 42 Power analysis ........................................................................................................... 42 Sample ....................................................................................................................... 43 Measures .................................................................................................................... 44 Procedure ................................................................................................................... 49 Results ........................................................................................................................... 49 Assessments of abilities and non-ability factors ........................................................ 51 Argument generation task .......................................................................................... 51 Predictors of reasoning performance ......................................................................... 58 Discussion ..................................................................................................................... 67 CHAPTER 3 ..................................................................................................................... 73 Method .......................................................................................................................... 73 iv Power analysis ........................................................................................................... 74 Sample ....................................................................................................................... 74 Measures .................................................................................................................... 74 Procedure ................................................................................................................... 81 Results ........................................................................................................................... 82 Predictor variables ..................................................................................................... 83 Argument generation task .......................................................................................... 88 Missing data and adjusted analysis plan .................................................................... 89 Experimental manipulation results (Hypotheses 2 through 4) .................................. 91 Individual differences results (Hypotheses 5 through 8) ........................................... 96 Exploratory Analyses .............................................................................................. 101 Discussion ................................................................................................................... 112 CHAPTER 4 ................................................................................................................... 124 Predictors of Reasoning Performance ......................................................................... 124 Methodological Considerations................................................................................... 126 Limitations .................................................................................................................. 127 Conclusion ................................................................................................................... 128 APPENDIX A ................................................................................................................. 132 APPENDIX B ................................................................................................................. 133 APPENDIX C ................................................................................................................. 134 APPENDIX D ................................................................................................................. 135 REFERENCES ............................................................................................................... 139 v LIST OF TABLES Table 1: Argument Prompts ............................................................................................. 47 Table 2: Descriptive Statistics for Person-Level Predictors (Study 1) ............................. 52 Table 3: Correlations Between Person-level Predictors (Study 1) .................................. 52 Table 4: Descriptive Statistics for Reasoning Items (Study 1) ........................................ 54 Table 5: Myside