Copyright is owned by the Author of the thesis. Permission is given for a copy to be downloaded by an individual for the purpose of research and private study only. The thesis may not be reproduced elsewhere without the permission of the Author. Exploring Factors that Influence Judgements of Climate Change Statements A thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Psychology at Massey University, Manawatū, New Zealand. Vathsala Sagayadevan 2020 II Abstract This aim of the current study was to examine the effect of repetition (i.e., illusory truth effect) and non-probative photographs (i.e., truthiness effect) on mean truth ratings of climate change statements using a within-subjects design. A total of 80 participants were asked to provide truth ratings to climate change statements in two parts. At Time 1, half of the statements appeared with photographs and half without photographs, while at Time 2, repeated statements from the first part were intermingled with a set of new statements. None of the statements at Time 2 appeared with photographs. It was hypothesized that statements paired with photographs and repeated statements would receive higher truth ratings than statements not paired with photographs and new statements. Likewise, it was predicted that repeated statements that had been paired with photographs at Time 1 would receive higher truth ratings compared to repeated statements that were not paired with photographs. Three planned comparisons and a paired samples t-test were used to assess the effect of repetition and photographs on truth ratings. The only significant difference in truth ratings observed was between repeated and new statements, with repeated statements receiving higher mean truth ratings than new statements. No influence of photographs or a cumulative effect of both repetition and photographs was found. Exploratory analyses of the effect of the type of statement (true or false) on truth ratings showed that, true statements were perceived as truer, and false statements were perceived as less true when paired with photographs (as compared to when not paired with photographs). Implications of findings, limitations of the current study and future research are also discussed. Keywords: fluency, truthiness, illusory truth effect III Acknowledgements First and foremost, I would like to thank my supervisor Dr Stephen Hill for his consistent guidance and support. His positive comments motivated me to keep going and this thesis would not have been possible without him. Secondly, I would like to thank Dr Natasha Tassell-Matamua for taking time to listen to my study findings and in providing her input for this study. To my wonderful flatmate Debbie, your optimism and upbeat nature always made my day and helped me navigate through tough days when writing this thesis. Last but not least, I would like to thank my family for their unwavering support and faith in me. Thank you for being so understanding and being there for me when I needed the moral support. This project was evaluated and approved by the Massey University Human Ethics Committee: Southern B (refer to Appendix A for approval letter). IV Table of Contents Abstract .............................................................................................................................. II Acknowledgements ........................................................................................................... III List of Tables .................................................................................................................. VIII List of Figures ................................................................................................................... IX Chapter One ........................................................................................................................ 1 Introduction ........................................................................................................................ 1 Chapter Two ....................................................................................................................... 3 Literature Review ............................................................................................................... 3 The Illusory Truth Effect ................................................................................................ 3 Russiagate controversy and the vaccination-autism debate. ........................................... 3 Assessing the truth effect............................................................................................... 5 Mechanisms Underlying the Illusory Truth Effect ........................................................ 6 The memorial account. .................................................................................................. 6 Frequency explanation .................................................................................................. 8 Recognition explanation ................................................................................................ 8 Processing fluency ...................................................................................................... 10 Familiarity as a mediator ............................................................................................. 10 Source recollection, credibility, and dissociation. ........................................................ 11 Moderators of the Illusory Truth Effect ...................................................................... 14 Judgement context. ...................................................................................................... 15 Pre-existing knowledge. .............................................................................................. 17 The Truthiness Effect ................................................................................................... 19 Mechanisms Underlying the Truthiness effect ............................................................. 21 Fluency. ...................................................................................................................... 21 Confirmation bias. ....................................................................................................... 22 Moderators of the Truthiness Effect ............................................................................ 23 V Judgement context. ...................................................................................................... 23 Pre-existing knowledge. .............................................................................................. 25 Other Fluency Manipulations ....................................................................................... 28 Climate Change Communication ................................................................................. 30 Average knowledge and understanding of climate change. .......................................... 30 Factors influencing beliefs about climate change. ........................................................ 31 Use of Repetition in Climate Change Communication ................................................ 33 Fake news ................................................................................................................... 34 The Use of Photographs in Climate Change Communication ..................................... 35 Summary ....................................................................................................................... 37 Study Aims and Hypotheses ......................................................................................... 38 Chapter Three ................................................................................................................... 40 Method .............................................................................................................................. 40 Participants ................................................................................................................... 40 Pilot study. .................................................................................................................. 40 Main study. ................................................................................................................. 40 Measures ........................................................................................................................ 41 Demographic questions. .............................................................................................. 41 Climate change statements (pilot study). ..................................................................... 41 Climate change statements (main study). ..................................................................... 42 Climate change photographs. ....................................................................................... 44 Free-response questions............................................................................................... 46 Attention check questions ............................................................................................ 46 Sample Size Determination ........................................................................................... 47 Sample Demographics and Testing Location ............................................................... 47 Procedure .....................................................................................................................