Melina Tsapos

A central debate in conspiracy theory research concerns how to conceptualise conspiracy theories in a way that advances our understanding of the phenomena themselves as well as of those who believe in them. This debate remains unresolved, with researchers adopting widely different positions: while some argue for a purely descriptive understanding, others are strongly committed to the view that conspiracy theories are, or can be shown to be, inherently irrational. This paper reconstructs the controversy, arguing that it stems from two distinct scholarly motives: to attain objective knowledge of the phenomena in question versus to defend beliefs and norms that are part of the researcher’s own cultural context. By examining the epistemological and methodological challenges in this field, I highlight how competing frameworks—normative cultural biases versus objective scientific inquiry—shape our understanding of rational belief. When cultural biases influence research, they risk narrowing its scope and undermining the development of a comprehensive understanding of conspiracy theories. Ultimately, even proponents of normative cultural approaches can acknowledge that such perspectives fail to capture the full complexity and significance of these phenomena.

Philosophical debate on conspiracy theories divides between particularism, which argues for an evaluation of conspiracy theories on a case by case, and generalism, which treats them — as a class — as inherently irrational. This divide complicates how we interpret empirical research on conspiracy theory belief. Many psychological and social-scientific studies emphasize correlations between conspiracy belief and traits such as narcissism, illusory pattern perception, and paranoia, seemingly supporting a generalist view. Yet conspiracy belief is also widespread in the general population, a fact that is difficult to reconcile with a purely pathological account. A unified explanation of what motivates conspiracy belief is still lacking. I address this gap by introducing a framework that incorporates multiple dimensions of conspiracy belief. The framework identifies three core motivations: group cohesion, cognitive needs, and truth-seeking. I propose that generalists and particularists each focus on different regions of this shared motivational space. I also outline a relatively narrow area within the space where pathological conspiracy belief is best located. Ultimately, however, determining where most conspiracy theories fall — and what reasons people have for endorsing them — remains an empirical question.

This introduction to this special issue of Inquiry looks at recent work in the philosophy of conspiracy theory theory. Looking at two related worries expressed in the wider conspiracy theory theory (the academic study of conspiracy theories) – the Problem of Conspiracy Theories and the Problem of Conspiracy Theorists – this special issue argues that recent work in the philosophy of conspiracy theories is getting all the more closer to not just an epistemic understanding of what, if anything, is wrong with belief in conspiracy theories, but also a framework for both investigating conspiracy theories and understanding how we should talk about the beliefs of conspiracy theorists.

Concerns have been raised by both researchers and authorities regarding conspiracy theorists rejecting experts. To address the validity of these concerns, we need to delve into two key inquiries regarding who qualifies as an expert on conspiracy theories, and what constitutes an epistemically rational response (from a conspiracy theorist) when faced with expert testimony. The first inquiry presents a challenge when considering a reputationalist versus a realist account of experts. On the reputationalist account rejecting experts may be viewed as little more than rejecting those whom society has collectively deemed as experts. Alternatively, adopting a realist account raises the challenge of determining who the genuine experts are. I argue that the realist account is the more compelling option for pursuing the first question. Moreover, I explore two prevalent accounts from existing literature that prescribe how epistemic agents should respond to expert testimony: the Preemptive View and the Community View. Through an examination using the simulation program Laputa, I demonstrate that both accounts are insufficient. Consequently, I argue that without a clear identification of experts in the broader context of conspiracy theories, the initial concern lacks a solid foundation, and the sense of urgency may be unwarranted.

This doctoral thesis investigates the conceptual, epistemological, and psychological dimensions of conspiracy theories, aiming to develop a more precise and philosophically rigorous framework for understanding and evaluating them. The work is structured around five original papers that address key questions: What constitutes a conspiracy theory? Are such theories inherently irrational? How should we conceptualize their epistemic status in light of expert testimony, trust, and cognitive psychology? The thesis begins by examining the contested nature of the term conspiracy theory, revealing the limitations of both pejorative and overly broad definitions. It engages with the philosophical debate between generalism and particularism, arguing for a neutral, theoretically useful definition based on Carnapian conceptual engineering. It then explores whether belief in conspiracy theories can be rational, with attention to decision-theoretic considerations and the epistemic role of experts. The final chapter investigates why individuals come to endorse conspiracy theories, evaluating claims that such beliefs are primarily driven by irrationality, cognitive biases, or social belonging. A central contribution is the development of the Dimensions framework—a descriptive tool for analysing conspiracy theories not solely in terms of truth or falsity, but with attention to the contexts, motivations, and epistemic norms surrounding their adoption. This framework enables a more nuanced understanding of conspiracy theories as complex social phenomena. By combining conceptual analysis, epistemological evaluation, and psychological insight, the thesis offers a comprehensive and interdisciplinary approach that contributes to ongoing debates in conspiracy theory theory—the academic study of conspiracy theories—as well as to social epistemology more broadly.

Despite decades of research on the emergence of human speech capacities, an integrative account consistent with hominin evolution remains lacking. We review paleoanthropological and archaeological findings in search of a timeline for the emergence of modern human articulatory morphological features. Our synthesis shows that several behavioral innovations coincide with morphological changes to the would-be speech articulators. We find that significant reductions of the mandible and masticatory muscles and vocal tract anatomy coincide in the hominin fossil record with the incorporation of processed and (ultimately) cooked food, the appearance and development of rudimentary stone tools, increases in brain size, and likely changes to social life and organization. Many changes are likely mutually reinforcing; for example, gracilization of the hominin mandible may have been maintainable in the lineage because food processing had already been outsourced to the hands and stone tools, reducing selection pressures for robust mandibles in the process. We highlight correlates of the evolution of craniofacial and vocal tract features in the hominin lineage and outline a timeline by which our ancestors became ‘pre-adapted’ for the evolution of fully modern human speech.

This introduction to this special issue of Inquiry looks at recent work in the philosophy of conspiracy theory theory. Looking at two related worries expressed in the wider conspiracy theory theory (the academic study of conspiracy theories) – the Problem of Conspiracy Theories and the Problem of Conspiracy Theorists – this special issue argues that recent work in the philosophy of conspiracy theories is getting all the more closer to not just an epistemic understanding of what, if anything, is wrong with belief in conspiracy theories, but also a framework for both investigating conspiracy theories and understanding how we should talk about the beliefs of conspiracy theorists.

Concerns have been raised by both researchers and authorities regarding conspiracy theorists rejecting experts. To address the validity of these concerns, we need to delve into two key inquiries regarding who qualifies as an expert on conspiracy theories, and what constitutes an epistemically rational response (from a conspiracy theorist) when faced with expert testimony. The first inquiry presents a challenge when considering a reputationalist versus a realist account of experts. On the reputationalist account rejecting experts may be viewed as little more than rejecting those whom society has collectively deemed as experts. Alternatively, adopting a realist account raises the challenge of determining who the genuine experts are. I argue that the realist account is the more compelling option for pursuing the first question. Moreover, I explore two prevalent accounts from existing literature that prescribe how epistemic agents should respond to expert testimony: the Preemptive View and the Community View. Through an examination using the simulation program Laputa, I demonstrate that both accounts are insufficient. Consequently, I argue that without a clear identification of experts in the broader context of conspiracy theories, the initial concern lacks a solid foundation, and the sense of urgency may be unwarranted.

Researchers have argued that believing in conspiracy theories is dangerous and harmful, both for the individual and the community. In the philosophical debate, the divide is between the generalists, who argue that conspiracy theories are prima facie problematic, and the particularists, who argue that since conspiracies do occur, we ought to take conspiracy theories seriously, and consider them on merit. Much of the empirical research has focused on correlations between conspiracy belief and personality traits, such as narcissism, illusory pattern perception, and paranoia, in the spirit of a generalist account. However, there is also ample empirical evidence that conspiracy belief is widespread in the population at large, which would be surprising and in need of explanation if the generalists were correct. In sociology and political science studies have demonstrated the role of group motivation and social aspects of belief in conspiracies. There is currently lacking a unified account of what motivates conspiracy belief that can capture the different intuitions, if possible, in one framework. This is the lacuna I wish to address, by introducing a framework that incorporate the many dimensions of conspiracy theories. The framework identifies three motivating factors for endorsing a conspiracy theory: group cohesion, cognitive needs, and truth seeking. A fourth dimension is the isolation value, or the level of ‘knowledge-anomie’ that the conspiracy theory takes. Thus, the framework is able to capture more normal cognitive functions that drive conspiracy beliefs, such as adopting to the in-group’s beliefs and the quest for truth, but also the plausibly more abnormal ones. Conspiracy theories can be positioned in a three-dimensional space depending on the degree to which they exemplify each motivating factor and the extent they deviate from the ‘knowledge-norm’. I suggest that the generalist and the particularist have focused on different parts of this common three-dimensional space. I also indicate a relatively small area where I believe pathological conspiracy belief is to be positioned. Ultimately, it is an empirical question what part of the space (pathological or otherwise) conspiracy theories occupy.

It is commonly assumed that personalization technologies used by Google for the purpose of tailoring search results for individual users create filter bubbles, which reinforce users’ political views. Surprisingly, empirical evidence for a personalization-induced filter bubble has not been forthcoming. Here, we investigate whether filter bubbles may result instead from a searcher’s choice of search queries. In the first experiment, participants rated the left-right leaning of 48 queries (search strings), 6 for each of 8 topics (abortion, benefits, climate change, sex equality, immigration, nuclear family, Islam, and taxation). An independent sample of participants were then asked to select one of these queries for each of the 8 topics. With the exception of the topic of Islam, participants were significantly more likely to select a query corresponding to their own political leaning, compared to other queries, explaining between 12% and 39% of the variance. A second experiment investigated the effect of the political leaning of the same queries on the overall political leaning of Search Engine Result Pages (SERPs) in Google Search. The top six results of each SERP were rated collectively by a third group of participants, explaining 36.3% of the variance across all 48 search terms (p < .00001). That is, (1) participants in our experiments tended to select own-side search queries, and (2) using those queries tended to yield own-side search results when using the Google search engine. Our results are consistent with the notion of a self-imposed filter bubble in which query selection plays a salient role.

A central debate in the conspiracy theory research concerns how to understand conspiracy theories in a theoretically fruitful way given our research interest to study the nature of such theories and those who believe in them. However, far from settling on one account, this is still an on-going dispute in which researchers take widely different positions. For instance, while some argue for a purely descriptive understanding, others seem strongly committed to the view that conspiracy theories are, or can be shown to be, inherently irrational. In an attempt to reconstruct this controversy, I argue that the disagreement arises because there are in fact two distinct motives underlying scholarly studies in the field: to attain objective knowledge of the phenomena in question versus to defend beliefs and norms that are part of the researcher’s own cultural context. This paper examines the epistemological and methodological challenges in the study of conspiracy theories, focusing on how competing frameworks—normative cultural biases versus objective scientific inquiry—shape our understanding of rational belief. I argue, finally, that if the motive is to attain objective knowledge, there is no serious alternative to the descriptive understanding of conspiracy theories.

The question of the rationality of conspiratorial belief ¬divides philosophers into mainly two camps. The particularists believe that each conspiracy theory ought to be examined on its own merits. The generalist, by contrast, argues that there is something inherently suspect about conspiracy theories that makes belief in them irrational. Recent empirical findings indicate that conspiratorial thinking is commonplace among ordinary people, which has naturally shifted attention to the particularists. Yet, even the particularist must agree that not all conspiracy belief is rational, in which case she must explain what separates rational from non-rational conspiratorial thinking. In this paper, I contrast three strategies to this end: 1) the probabilistic objectivist, who assesses the objective probability of conspiracies; 2) the subjectivist, who rather focuses on the perspective of the believer, and typically views the decision to believe in a conspiracy as a problem of decision making under risk. Approaches 1) and 2) rely on assessments of the probability of conspiracy which, I argue, limits their applicability. Instead, I explore 3) viewing the problem facing the potential believer as a decision problem under uncertainty about probabilities. I argue, furthermore, that focusing solely on epistemic utilities fails to do justice to the particular character of conspiracy beliefs, which are not exclusively epistemically motivated, and I investigate the rationality of such beliefs under a number of standard decision rules.

The simplest and most natural definition of the term ‘conspiracy theory’ leads us to the conclusion that we are all conspiracy theorists. Yet, I claim that most of us would not self-identify as such. In this paper I call this the problem of self-identification. Since virtually everyone emerges as a conspiracy theorist, the term is essentially theoretically fruitless. It would be like defining intelligence in a way that makes everyone intelligent. This raises the problem for theoretical fruitfulness, i.e. the problem of how to define the concept in a theoretically fruitful way. I suggest that these problems are currently causing confusion in the literature and present us with a dilemma, the conspiracy definition dilemma. I will present an analysis of the literature and what are on my reconstruction the solutions on offer, and argue that none is satisfactory. Either a) the solution will solve the problem of self-identification or b) it will potentially provide a theoretical fruitful definition, but no account does both.