Prior Belief Innuences on Reasoning and Judgment: A Multivariate Investigation of Individual Differences in Belief Bias Walter Cabral Sa A thesis submitted in conformity with the requirements for the degree of Doctor of Philosophy Graduate Department of Education University of Toronto O Copyright by Walter C.Si5 1999 National Library Bibliothèque nationaIe of Canada du Canada Acquisitions and Acquisitions et Bibliographic Services services bibliographiques 395 Wellington Street 395, rue WePington Ottawa ON K1A ON4 Ottawa ON KtA ON4 Canada Canada Your file Votre rëfërence Our fi& Notre réterence The author has granted a non- L'auteur a accordé une licence non exclusive Licence allowing the exclusive permettant à la National Libraq of Canada to Bibliothèque nationale du Canada de reproduce, loan, distribute or sell reproduire, prêter, distribuer ou copies of this thesis in microforni, vendre des copies de cette thèse sous paper or electronic formats. la forme de microfiche/film, de reproduction sur papier ou sur format électronique. The author retains ownership of the L'auteur conserve la propriété du copyright in this thesis. Neither the droit d'auteur qui protège cette thèse. thesis nor subçtantial extracts fi-om it Ni la thèse ni des extraits substantiels may be printed or otherwise de celle-ci ne doivent être imprimés reproduced without the author's ou autrement reproduits sans son permission. autorisation. Prior Belief Influences on Reasoning and Judgment: A Multivariate Investigation of Individual Differences in Belief Bias Doctor of Philosophy, 1999 Walter Cabral Sa Graduate Department of Education University of Toronto Belief bias occurs when reasoning or judgments are found to be overly infiuenced by prior belief at the expense of a normatively prescribed accommodation of dl the relevant data. The normative status and domain specifïcity / generality of belief bias was investigated in a muhivariate investigation. The research reported here also examined the role of cognitive capacity and thinking dispositions on belief bias. Cognitive capacity deals with those parameters of interest to traditional tests of psychometric intelligence whereas thinking dispositions captures those parameters that deal with what can be thought of as the goals of the reasoner-- how the capacities are put to use. A total of 124 participants recruited through an undergraduate university population participated in the study. Results suggested that belief bias is best interpreted as a nomormative tendency in human reasoning and judgment. Furthermore, some moderate correlations among indices of belief bias across domains as varied as deductive reasoning and perceptual judgment suggest belief bias has some degree of domain generality. Finally, the results also suggest that both cognitive capacity and thinking dispositions account for some unique variance in belief bias. The results for this last finding, however, was moderated by the type of reasoning or judgments participants were asked to make. Acknowledgements 1 thank my mother Maria, and my sisters Lama and Lesley for their personal support, encouragement, and love. Let me also thank here my father Albano, and my brother-in-law Robert. From my family 1 have learned to place great value on the the truly important things in Me. To the students in the Stanovich lab, both past and present, I offer my thanks. My thinking on matters of relevance to this work has no doubt benefited from discussions with Cindy Kaizer, Carol Kelley, Jason Riis, Robin Sidhu, Ron Stringer, and Maggie Toplak. I would particularly like to thank Maggie for taking the time to read this work and offering several helpfûl comments and suggestions for its defense. For similar reascris, 1 also thank several other students and faculty at the Department of Human Development and Applied Psychology, too many to name, but particularly Keith Oatley. To my cornmittee members Geofiey Fong, Chris Olsen, David Olson, and Uri Shafrir, a sincere thank you. Your engagement with this work has contributed enormously to my understanding and appreciation for the additional complexities involved in interpreting this body of data. To my supervisor Keith Stanovich, 1 offer my sincerest thanks. Nothing I can confine to a few lines here will express my full gratitude for Keith's extraordinary guidance, patience, and help. I simply could not have irnagined a better mentor. Intellectually, professionally, and personally, 1 have greatly benefited fkom Keith's efforts. Finally, to my loving wife Junko, I'd like to offer a heartfelt thank you. It pains me to think of the enormous sacrifices you have made in the last few years. Your love and support is something Y11 always cherish. 1 dedicate this thesis to you. Table of Contents Inbeoduction. .................................................................*......................-1 Belief Bias and the Normative Issue ................................................ 2 Bayes Theorem as a Normative Mode1 for Belief Revision ................... 3 Syllogistic Reasoning and the Normative Issue ...............................10 Normative Models as Justified Benchmarks for Optimal Reasoning.. i5 Addressing the Status of Normative Models.................................... 18 Ecological Validity and the Projection of Belief................................ 20 The Domain Specificity and Generdity of Belief Bias ........................22 Addressing the Domain Specificity and Generaliw Issue ................. 24 Predicting Belief Bias Using a Cognitive Capacitgr - Thinking Dispositions Frarnework ................................................ 27 The Research Strategy.................................................................. 34 Hypotheses ................................................................................. -35 Method................................................................................................ 37 Participants ................................................................................ 37 Prior Belief Reasoning and Judgment Tasks ..................................-38 Syllogistic Reasoning Test ...................................................-38 Height Judgment Tasks ...................................................... 39 Argument Evaluation Test .................................................. -42 Covariation Judgment Task ................................................. 45 Confounded Variable Task .................................................. -49 Social Perception Tasks ................................................................ 52 . .............................................................. Opinion Prediction. 52 Knowledge Prediction ........................................................33 General Cognitive Ability Me asures .............. .... .....................*..-55 Thinking Dispositions Questionnaire .............................................57 Flexible Thinking Scale ....................................................... 57 Counterfactual Thinking Scale ............................................. 58 Absolutism ........................................................................ 58 Dogmatism ........................................................................ 59 Belief Identification .............................................................59 Impulsiveness ....................................................................6û D eliber ation .......................................................................60 OpennessValues................................................................ 60 Openness-Ideas ................................................................. -61 Categorical Thinking .......................................................... 61 Need for Closure-................................................................ 61 .. Faith in Intuition ................................................................6l Head Over Heart ................................................................-62 Paranormal Beliefs .......... ...... ..., ...................................... -62 Superstitious Thinking........................................................ Q Consideration of Future Consequences Scale..................... .... 62 Concept of Luck .................................................................. 63 Response Bias and Effort Checks ................................................... 63 Impression Management...................................... L Effort Probe ........................................................................ 63 Demographic and Print Exposure Measures ................................... 63 Procedure .................................................................................. -64 Overview of the Methodological Approach....................................... 6û Redtsand Discussion ......................................................................... 70 Individual Differences in Prior Belief Task Performance .................. 70 The Correlates of Normative Responses on the Prior Belief Tasks .....-72 Consequences of Projecting Belief on the Accuracy of Tracking the Environment.............................................................................. -78 Exploring the Domain Specificity and Generality of Belief Bias ......... -82 Does Cognitive Ability Alone Provide the Underlying Mechanism for the Observed Degree of Domain Generality? ............................... 87 The Role of Thinking Dispositions on Prior Belief Task Performance ...............................................................................!X