Why do irrational beliefs spread so easily? Lisa Bortolotti, professor of philosophy at the University of Birmingham, revisits her project, The Epistemic Innocence of Imperfect Cognitions, part of the Arts and Humanities Research Council’s Science in Culture Theme led by the Institute of Philosophy.

In recent months, the phenomenon of conspiracy theories has drawn attention to how irrational we can all be. At a time when the news is endlessly devoted to the developments of the global pandemic and the turmoil that causes political instability in many countries across the world, theories have surfaced denying the very existence of the threats that are making our lives a nightmare, or hypothesising improbable plots by powerful individuals or organisations at the expense of our safety or freedom. Such theories often influence people’s behaviour and are considered both detrimental and dangerous: doubting the efficacy of the anti-Covid vaccine can compromise vaccination campaigns and doubting the legitimacy of an election can cause violent protests and riots. In either case, irrationality costs lives.

In the course of the Arts and Humanities Research Council project, The Epistemic Innocence of Imperfect Cognitions (2013–14), I wanted to understand why irrational beliefs spread so easily and are so difficult to give up, even in the face of powerful counter evidence. What makes them attractive and resistant to challenges? Our reaction to irrational beliefs is often simplistic and one-sided. We are so concerned with finding fault with the irrational belief that we forget to notice what advantages it might have. And because we tend to ignore its advantages, we also fail to understand its tenacity. We quickly dismiss a belief that is not well supported by the existing evidence or not responsive to new evidence, without asking what role that belief may play.

The theory that Covid-19 was created in a lab in Wuhan is epistemically irrational as things stand, in the sense that the theory is not backed up by evidence. There are experts who can convincingly explain how viruses emerge and mutate in ways that do not involve any evil, secret plot. But the thought that the pandemic is not just a natural occurrence, but a consequence of ill-intentioned villains, can be strangely comforting. It means that the world is not as unpredictable as it seems. It means that we can prevent something like this from happening again if we punish those responsible. An irrational belief that is aimed at explaining events by relieving our anxiety and restoring our sense of control will be difficult to replace with a more rational belief, unless the more rational belief we aim to replace it with will also play a similar psychological function.

So, one of the core ideas of the project was to think about the benefits that an irrational belief can have and see whether those benefits may begin to explain why irrationality is such a permanent feature of our lives. The case of comforting illusions was not particularly original, though. We have long known that a positive spin on events is often preferred to a more realistic one due to the fact that we engage in motivated reasoning, are vulnerable to biases, and are selective and creative when we remember our past. The counterintuitive idea of the project was that the irrational belief may have not just psychological benefits, but also epistemic ones.

There are circumstances in which the adoption of the irrational belief and its maintenance favour our capacity to interact with our physical and social world in a way that facilitates meaningful social interactions, resulting in the acquisition of new relevant information. This is especially evident when the person who adopts and maintains the irrational belief cannot form a more rational belief, due to either problems affecting perception, memory, and reasoning, or assumptions about the type of explanation that is appropriate or desirable in that context.

When there is no better alternative, the irrational belief may have considerable epistemic advantages with respect to suspending judgement or living with uncertainty, and can be tolerated until a better alternative becomes available. In my recent monograph, The Epistemic Innocence of Irrational Beliefs (OUP 2020), I consider five such cases in detail: distorted memory beliefs in dementia, confabulatory explanations of choice, elaborated delusions in schizophrenia, motivated delusions, and unrealistically optimistic beliefs.

A comprehensive and sympathetic study of irrationality does not need to result in an apology of irrational thought or a stubborn denial of its negative consequences for the thriving of individuals and societies. Rather, it is motivated by the conviction that only when we understand what role irrational beliefs play in our complex, heavily constrained agency can we halt their spreading without losing anything else we care about. Know your enemy.

Lisa Bortolotti is professor of philosophy at the University of Birmingham. Her new book The Epistemic Innocence of Irrational Beliefs is published by Oxford University Press. She can be found on Twitter @lisabortolotti.

Cover image: The lagoon in Nora, Sardinia. Lisa Bortolotti