gathering data on conspiracy adherents, especially in online spaces (e.g., Del Vicario et al. 2016). However, we still struggle as a research community to theorize about how these people might be similar to or different from most of our participants.
The COVID-19 pandemic illustrates how research on the psychology of conspiracy theories has been limited in some of these ways. Over 100 studies have been published on the consequences of COVID-19 conspiracy beliefs (see Biddlestone et al. 2020, Pummerer et al. 2022, Romer & Jamieson 2020 for just three examples of this explosion of research; for meta-analyses, see Bierwiaczonek et al. 2022, van Mulukom et al. 2022). These studies have provided useful information at an important time when scientists were endeavoring to help with a world crisis. It is also worth pointing out that most of this research leads to the same conclusion—that conspiracy beliefs are associated with lower intentions to engage in activities to stop the spread of the virus, such as taking a vaccine and engaging in social distancing. However, no overall theoretical framework has guided this research, so the findings have again been rather piecemeal and disconnected. The bulk of the research has been cross-sectional and has been conducted on general populations rather than strong believers. Furthermore, because no established measurement scales existed, researchers designed their own scales to measure COVID-19 conspiracy beliefs, and in some cases these may have led to an overestimation of the prevalence of these beliefs in the population due to the way they were anchored (see Sutton & Douglas 2022). It is likely that these issues arose because researchers were responding rapidly to a crisis and were not working with other researchers to combine resources and share theoretical perspectives. However, a crucial problem is that this research, like much of the research on the psychology of conspiracy theories generally, has not paid enough attention to the content and features of the conspiracy theories themselves.
In the next section, we advocate taking a step back to reexamine closely what conspiracy theories are—their core features and what makes them different from other types of belief. We argue that this is crucial for theoretical progress in the coming years. A clear definition will guide the operationalization of conspiracy belief, therefore sharpening the testing of theory. It will help identify features of conspiracy theories that affect their causes, consequences, and communication. In so doing, it will help integrate these three lines of research, which after all are all about the same thing.
THE DEFINING PROPERTIES OF CONSPIRACY THEORIES AS CAUSAL PROPERTIES
In this analysis we are inspired by the influential philosophical analysis of causality put forward by Shoemaker (1980). In this analysis, causality is understood in terms of the underlying properties of the objects involved in events. Much can be gleaned about the likely causal functions of an object of inquiry by paying close attention to, and building theory from, its essential properties.
Shoemaker (1980, p. 109) gives the following example:
When one event causes another, this will be in part because of the properties possessed by their constituent objects. Suppose, for example, that a man takes a pill and, as a result, breaks out into a rash. Here the cause and effect are, respectively, the taking of the pill and the breaking out into a rash. Why did the first event cause the second? Well, the pill was penicillin, and the man was allergic to penicillin. No doubt one could want to know more—for example, about the biochemistry of allergies in general and this one in particular. But there is a good sense in which what has been said already explains why the one event caused the other.
By analogy, we argue that the effects of exposure to conspiracy theories depend on key features of the conspiracy theories as well as of the people who are exposed to them.
