title: An examination of the factorial and convergent validity of four measures of conspiracist ideation, with recommendations for researchers.
abstract: A number scales have been developed to measure conspiracist ideation, but little attention has been paid to the factorial validity of these scales. We reassessed the psychometric properties of four widely-used scales, namely the Belief in Conspiracy Theories Inventory (BCTI), the Conspiracy Mentality Questionnaire (CMQ), the Generic Conspiracist Beliefs Scale (GCBS), and the One-Item Conspiracy Measure (OICM). Eight-hundred-and-three U.S. adults completed all measures, along with measures of endorsement of 9/11 and anti-vaccination conspiracy theories. Through both exploratory and confirmatory factor analysis, we found that only the BCTI had acceptable factorial validity. We failed to confirm the factor structures of the CMQ and the GBCS, suggesting these measures had poor factorial validity. Indices of convergent validity were acceptable for the BCTI, but weaker for the other measures. Based on these findings, we provide suggestions for the future refinement in the measurement of conspiracist ideation.
authors.affiliation: Department of Psychology, Anglia Ruskin University, Cambridge, Cambridgeshire, United Kingdom.|Department of Psychology, HELP University College, Kuala Lumpur, Malaysia.
authors.forename: Viren
authors.initials: V
authors.lastname: Swami
authors.affiliation: Department of Psychology, University of Westminster, London, United Kingdom.
authors.forename: David
authors.initials: D
authors.lastname: Barron
authors.affiliation: Department of Clinical, Educational, and Health Psychology, University College London, London, United Kingdom.
authors.forename: Laura
authors.initials: L
authors.lastname: Weis
authors.affiliation: Department of Basic Psychological Research and Research Methods, School of Psychology, University of Vienna, Vienna, Austria.
authors.forename: Martin
authors.initials: M
authors.lastname: Voracek
authors.affiliation: Research Methods, Assessment, and iScience, Department of Psychology, University of Konstanz, Konstanz, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Stieger
authors.affiliation: Department of Clinical, Educational, and Health Psychology, University College London, London, United Kingdom.
authors.forename: Adrian
authors.initials: A
authors.lastname: Furnham
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003469:Culture; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011057:Politics; D011594:Psychometrics; D015203:Reproducibility of Results; D013850:Thinking; D055815:Young Adult