Measurement Issues and the Role of Cognitive Biases

188 Pages·2014·1.11 MB·English

Measurement Issues and the Role of Cognitive Biases in
Conspiracist Ideation

Robert A. Brotherton

Department of Psychology
Goldsmiths, University of London

A thesis submitted for the degree of Doctor of Philosophy at Goldsmiths, University
of London in October 2013
Statement of Originality

This thesis represents my own original work towards this research degree and
contains no material which has been previously submitted for a degree at this
University or any other institution, except where due acknowledgement is made.

Robert A. Brotherton
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Acknowledgements

My sincerest thanks go to everyone who helped make this thesis what it is:

To my supervisors Chris French (not only the best mentor I could hope for,
but a good friend as well), Tomas Chamorro-Premuzic (for guiding the first half of
this research), and Alan Pickering (for coming on board later, but having no less
input for it). To Pam Heaton and Elisabeth Hill for deciding that this work might be
worth funding, and to the Economic and Social Research council for agreeing. To
Karen Douglas, who is responsible for my interest in the psychology of conspiracy
theories in the first place. To Mark Williams, James Moore, Adrian Furnham, Paul
Rogers, Patrick Leman, Rob Teszka, and various peer-reviewers for valuable help,
advice, and constructive criticism. Most of all, for unending support and
encouragement, to my parents, Ann and Bob, and my partner Lindsay.

And, last but not least, to everyone who participated in this research –
particularly those who suspected me of being a government shill.

This work was supported by the Economic and Social Research Council [grant
number ES/I90249X]

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Related Publications

Some of the work contained within this dissertation has appeared in the
following publications.

A version of the section of Chapter 1 concerning the definition of ‗conspiracy
theory‘ was published in:
Brotherton, R. (2013). Towards a definition of ―conspiracy theory.‖ PsyPAG
Quarterly, 88(3), 9–14.

A version of Chapter 2, concerning the development of a novel measure of
conspiracist ideation, was published in:
Brotherton, R., French, C. C., & Pickering, A. D. (2013). Measuring belief in
conspiracy theories: The generic conspiracist beliefs scale. Frontiers in
Personality Science and Individual Differences, 4: 279.
doi:10.3389/fpsyg.2013.00279

A version of Study 5b, concerning conspiracist ideation and susceptibility to
the conjunction fallacy, has been accepted for publication in:
Brotherton, R., & French, C. C. (in press). Belief in conspiracy theories and
susceptibility to the conjunction fallacy. Applied Cognitive Psychology.

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Abstract

Conspiracy theories are a prominent feature of contemporary culture, and can
have far-reaching consequences for believers and disbelievers alike. Until recently,
however, relatively little research has examined the psychological origins of
conspiracist beliefs. A growing amount of research has now begun to reveal the
personality, motivational, cognitive, and social factors associated with belief in
conspiracy theories. The current thesis aims to contribute to this literature in two
main ways.
First, the existing literature is limited by the lack of a validated measurement
device. Aiming to address this need, Chapter 2 details the creation of a novel
measure of conspiracist ideation, the Generic Conspiracist Beliefs (GCB) scale, from
item selection (Study 1) through to psychometric validation (Studies 2, 3, and 4).
This measure assesses generic conspiracist ideation, therefore offering greater
practical utility and theoretical validity than existing measures which assess
endorsement of conspiracy theories based on specific world events.
Second, the literature may benefit from incorporating conspiracism into the
wider theoretical framework of anomalistic psychology. Chapters 3 and 4 employ the
newly created GCB to investigate the role of representativeness heuristics –
according to which claims are judged plausible to the extent that they subjectively
appear typical of events in general – in conspiracist ideation. Study 5a predicted that
the proportionality bias would influence novel conspiracist attributions; however, the
data did not support this hypothesis. Study 5b predicted that susceptibility to the
conjunction fallacy would be associated with conspiracist ideation. This hypothesis
was supported. Finally, Chapter 4 predicted that conspiracist ideation would be
associated with biased attributions of intentionality. Support for this hypothesis was
mixed; the findings suggest that an inferential bias towards attributions of
intentionality predicts conspiracist ideation, but a perceptual bias does not. In sum,
the findings suggest that conspiracist beliefs may be a product, in part, of certain
representativeness biases.

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Table of Contents

Statement of Originality 2
Acknowledgements 3
Related Publications 4
Abstract 5

Chapter 1. General Introduction
Overview 12
A brief introduction to conspiracy theories 15
The prevalence of conspiracy theories 15
The consequences of conspiracy theories 18
Towards a working definition of ‗conspiracy theory‘ 20
The characteristics of conspiracy theories 21
Definition summary 26
Review of the psychological literature 27
Associations between conspiracy beliefs 27
Sociodemographic correlates 31
Individual differences 33
Cognitive biases and heuristics 39
Summary of the literature 46
Limitations and research objectives 47
Research programme 49

Chapter 2. Measuring Belief in Conspiracy Theories: The Creation of a
Generic Conspiracist Beliefs Scale
Introduction 52
Previous approaches towards measuring conspiracist beliefs 53
Measuring generic conspiracist beliefs 55
Overview of the present studies 56
Study 1: Identifying essential facets of conspiracism 57
Method 57
Results 58
Discussion 64
Study 2: Factor structure, reliability & criterion validity 64
Method 65
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Table of Contents (continued)

Results 66
Discussion 71
Study 3: Convergent validity and additional evidence of criterion-related
validity 72
Method 72
Results 74
Discussion 75
Study 4: Discriminant validity 75
Method 76
Results 77
Discussion 78
General discussion 79
Summary and conclusions 82

Chapter 3. Conspiracy Theories and Judgements by Representativeness: The
Proportionality Bias and the Conjunction Fallacy
Introduction 84
The representativeness heuristic 84
Representativeness and judgements of causality 86
Representativeness and anomalous beliefs 87
Overview of the current studies 88
Study 5a: Belief in conspiracy theories and the proportionality bias 90
Introduction 90
Method 92
Results 95
Discussion 97
Study 5b: Belief in conspiracy theories and susceptibility to the conjunction
fallacy 100
Introduction 100
Method 103
Results 105
Discussion 107
General discussion 110

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Table of Contents (continued)

Chapter 4. Representativeness Continued: Conspiracist Ideation and
Judgements of Intentionality
Introduction 112
Inferring intent 112
Overattribution of intentionality 114
Intentionality and conspiracy theories 116
Overview of studies 118
Study 5c: Conspiracist ideation and inferences of intentionality 119
Method 119
Results 121
Discussion 124
Study 6: Conspiracist ideation and perceived intentionality 125
Method 125
Results 127
Discussion 129
Study 7: Individual differences in anthropomorphisation 130
Method 131
Results 132
Discussion 133
Study 8: Associations between anthropomorphisation and intentional
inferences 133
Method 133
Results 135
Discussion 136
General discussion 138
Summary and conclusions 142

Chapter 5. General Discussion
Purposes and key findings of the present research 144
Background and rationale 144
Key findings 147
Summary and implications 150
Research limitations 153
Future directions 157
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Table of Contents (continued)

Conclusion 160

References 161
Appendix 2.1. Item-loadings for the alternative 6-factor solution in Study 1 182
Appendix 2.2. GCB scale instructions and item wording 185
Appendix 3.1. Proportionality bias instructions and vignette wording 186
Appendix 3.2. Wording of novel conspiracy-themed conjunction items 187

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List of Tables

2.1. Comparison of results of EFA Eigenvalues with PA Eigenvalues.
2.2. Conspiracist Beliefs Scale (long-form) items and factor loadings.
2.3. Correlations between factor scores and overall Conspiracist Beliefs Scale (long-
form) score.
2.4. GCB scale items and standardised factor loadings obtained with exploratory
factor analysis.
2.5. Item standardised factor loadings obtained with confirmatory factor analysis.
2.6. Correlations between latent variables.
2.7. Multicollinearity diagnostics for regression model.
2.8. Results of multiple regression analysis with GCB factor scores predicting 9/11
conspiracist beliefs.
2.9. Means, standard deviations, and interscale correlations for Study 3.
2.10. Means, standard deviations, and interscale correlations for Study 4.

3.1. Mean ratings for likelihood of statements being true (standard deviations in
parentheses), and MANOVA results.

4.1. Results of multiple regression with intentional inferences and anthropomorphism
predicting conspiracist ideation.

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