Measuring Belief in Conspiracy Theories: The Generic Conspiracist Beliefs Scale

TLDR

Conspiracy theory beliefs are poorly understood, yet stable individual differences exist, and existing self-report measures focus on specific events but lack psychometric validation and have practical and theoretical limitations. The study introduces the Generic Conspiracist Beliefs (GCB) scale, a novel measure of generic conspiracist ideation. The 15‑item GCB scale was developed and validated across four studies, sampling from five conspiracist facets identified in an exploratory factor analysis. The GCB scale demonstrated strong psychometric properties across four studies, with exploratory factor analysis revealing five facets and subsequent studies confirming internal reliability, validity, and test‑retest stability, thereby establishing it as a sound, practical measure of conspiracist ideation.

Abstract

The psychology of conspiracy theory beliefs is not yet well understood, although research indicates that there are stable individual differences in conspiracist ideation – individuals' general tendency to engage with conspiracy theories. Researchers have created several short self-report measures of conspiracist ideation. These measures largely consist of items referring to an assortment of prominent conspiracy theories regarding specific real-world events. However, these instruments have not been psychometrically validated, and this assessment approach suffers from practical and theoretical limitations. Therefore, we present the Generic Conspiracist Beliefs (GCB) scale: a novel measure of individual differences in generic conspiracist ideation. The scale was developed and validated across four studies. In Study 1, exploratory factor analysis of a novel 75-item measure of non-event-based conspiracist beliefs identified five conspiracist facets. The 15-item GCB scale was developed to sample from each of these themes. Studies 2, 3 and 4 examined the structure and validity of the GCB, demonstrating internal reliability, content, criterion-related, convergent and discriminant validity, and good test-retest reliability. In sum, this research indicates that the GCB is a psychometrically sound and practically useful measure of conspiracist ideation, and the findings add to our theoretical understanding of conspiracist ideation as a monological belief system unpinned by a relatively small number of generic assumptions about the typicality of conspiratorial activity in the world.