Here, we make a case for considering beliefs to be conspiracy theories only when the alleged conspiracy is of public interest. This entails that publicness (Arendt 1998, Georgiou & Titley 2022) is a crucial defining dimension. Conspiracy theories are represented as belonging to the public. The events they are about are large and general enough to concern the public, who should know about the conspiracy because their interests have been—or could be—affected. Making the conspiracy public knowledge helps to protect public interests by preventing the conspiracy from progressing further, sanctioning the conspirators, and/or correcting the public record (see Tetlock 2002 for an analysis of the social functions of cognition). The claim made implicitly by every conspiracy theory, therefore, is that the wider public should (but do not) know about a conspiracy. Each serious conspiracy theory is in fact bidding to become incorporated in public knowledge.
The public interests at stake in conspiracy theories have been acknowledged in different forms in previous scholarly definitions. For example, some define the events as being socially significant [e.g., a conspiracy theory is “a lay theory about socially significant and negative events (i.e., assassinations, terrorist attacks, etc.), which often implies the intervention of one or more groups acting in secret” (Wagner-Egger & Bangerter 2007, p. 31)]. Others define conspiracy theories as being about complex events involving many people [e.g., they “explain complex world events with reference to secret plots hatched by powerful groups” (Imhoff & Bruder 2014, p. 25)]. We prefer the more general criterion that conspiracy theories are of public interest because it captures various reasons for conspiracy theories to be of public concern. This abstract criterion, as we shall see, also permits the logical derivation of several characteristic features from our core definition of a conspiracy theory as a belief that two or more actors have coordinated in secret to achieve an outcome and that their actions are of public interest but not widely known by the public.
One of the advantages of definitional and descriptive work is, of course, to help us decide which beliefs or statements are the proper subject of conspiracy theory research, and thus to set the limits of our research topic. Beyond this advantage, however, we will argue that the correlates, consequences, and communication of conspiracy theories should depend on features that set them apart from other kinds of beliefs and which vary by degree even within conspiracy theories. In the following pages we therefore expand this definition, illustrate how it can incorporate insights from the conspiracy literature, and then discuss how it can help generate and organize further theoretical progress. We argue that from the core definition of conspiracy theories, we can also deduce that they are oppositional, concern malevolent or forbidden acts, are agentic (i.e., ascribe historical agency to individuals and small groups), are epistemically risky, and are widely shared and potentially generative social constructs (see the sidebar titled Conspiracy Theory).
A conspiracy theory is a belief that two or more actors have coordinated in secret to achieve an outcome and that their conspiracy is of public interest but not public knowledge. Conspiracy theories (a) are oppositional, which means they oppose publicly accepted understandings of events; (b) describe malevolent or forbidden acts; (c) ascribe agency to individuals and groups rather than to impersonal or systemic forces; (d) are epistemically risky, meaning that though they are not necessarily false or implausible, taken collectively they are more prone to falsity than other types of belief; and (e) are social constructs that are not merely adopted by individuals but are shared with social objectives in mind, and they have the potential not only to represent and interpret reality but also to fashion new social realities.
