Tuesday 25 May 2021

Social Approaches to Delusion (3): The Social Formation and Social Evaluation of Delusion

Today's post is by Sam Wilkinson (University of Exeter) and it is the third in the series “Social Approaches to Delusions”.

Sam Wilkinson

This series of posts has sought to show how there has been a “social turn” in thinking about delusions. The excellent posts by Kengo Miyazono and Dan Williams on their respective co-authored papers (Miyazono and Salice 2020; Williams and Montagnese preprint) are testament to the fruitfulness of going beyond individual cognition and individualistic epistemology when theorising about delusion.

In this post I draw inspiration from their work to reflect on precisely what we might mean by delusions being social.

Let’s draw a distinction between delusions being social in their formation (call this “the social formation claim”), and in their evaluation (call this “the social evaluation claim”). In other words, social factors (deficits in social cognition, social epistemology) may play a role in generating those things that we end up calling delusions (as Kengo and Dan’s papers suggest, in compatible but different ways). On the other hand, social factors (societal norms) may play a role in determining which candidate phenomena count as delusions (which is roughly what my expressivism paper suggests (Wilkinson 2020; see also here)).

On close inspection, these look like very different hypotheses, and they are conceptually entirely separable. To demonstrate their separability, consider two positions.

  • Position 1. The social formation claim is right: social cognitive and social epistemic factors are involved in the kinds of deviations that give rise to delusions. But the social evaluation claim is wrong: their status as delusions is entirely non-social, objective and descriptive (saying that someone is delusional is like saying that they have brown hair). 
  • Position 2. The social formation claim is wrong: many of the things that we call delusions have individualistic aetiologies. But the social evaluation claim is right: we give them delusional status, as I have suggested, based on a kind folk-epistemic disgust. 

These two positions, though conceptually coherent, are, I suggest, implausible, and the reason for this is that our practices of belief formation and of belief evaluation are closely, and non-accidentally, related. In short, we should accept both the social formation and the social evaluation claims.

Let us start with some key insights from both Kengo and Dan: we are profoundly social creatures who navigate a world with a variety of informational pitfalls. Where do such pitfalls typically come from? Not from perception (we do not inhabit a wacky world of illusions) but from testimony (we do inhabit a world where people may lie, mislead, conceal). So we need to be epistemically vigilant (Sperber et al. 2010). But we aren’t only individualistically vigilant: our vigilance is socially distributed. In other words, we give testimony about the quality of other individuals as sources of testimony.

What stronger way of flagging a poor testimonial source than to call someone delusional? (And when this is bolstered by the suggestion that there’s something (psychiatrically) wrong with them, the effect is strengthened further.) But we also flag good sources of testimony, and more general folk-epistemic trustworthiness, in subtle and implicit ways, through our social practices of taking people seriously (through which we encourage others to do the same).

How far can we push things? According to a moderate position, views that make use of individualistic approaches could be right, they just happen to be wrong. According to a more adventurous position, the individualistic notions are fundamentally misguided, or even incoherent. I’m not yet sure whether I’d want to adhere to it, but the adventurous position is worth exploring.

Take traditional epistemic notions like “evidence”. What is a private, individualistic notion of evidence? Often people talk about experiential evidence. If I genuinely believe something, then that is how I take the world to be. I believe it, because it strikes me that the world is thus. But when, then, do people ever believe without private evidence? In contrast, a public, social notion of evidence gets more purchase: grounding belief in evidence is about bringing others along with you.

Tuesday 18 May 2021

Social Approaches to Delusions (2): Bayesian Psychiatry and the Social Focus of Delusions

Today's post is by Daniel Williams and Marcella Montagnese and it is the second in the series “Social Approaches to Delusions”. Daniel is an Early Career Research Fellow at Corpus Christi College, University of Cambridge, and Marcella is a doctoral student in the Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, at King’s College London. Here Daniel and Marcella talk about their new paper “Bayesian Psychiatry and the Social Focus of Delusions”.


Daniel Williams
Daniel Williams

As with many other areas of psychology and philosophy, the study of delusions is taking a social turn. This has different manifestations. For example, in an extremely interesting article, Sam Wilkinson argues that the very attribution of delusional status to certain beliefs is wrapped up in social practices of folk-epistemic approval and disapproval. To call something a delusion, Wilkinson argues, is not to describe – or at least not only to describe – reality but to express a certain kind of disapproval at a violation of social-epistemic norms.

Other work focuses on the centrality of social cognition – and disturbances to social cognition – for understanding the kinds of beliefs that get characterised as delusions in psychiatry. This idea is central to Kengo Miyazono and Allesandro Salice’s fascinating “testimonial theory of delusion,” according to which a combination of testimonial isolation and testimonial discount play important and underappreciated roles in the formation, maintenance, and elaboration of delusions in schizophrenia. 

Vaughan Bell, Nichola Raihani, and – again – Sam Wilkinson similarly emphasise this reduced sensitivity to social context in their important manifesto for the importance of coalitional cognition for understanding delusions. Further, they speculate that evolved social mechanisms for managing social influence, affiliation, and strategic social behaviour are central for determining the overwhelmingly social themes of delusions, an idea that also plays a role in Joel and Ian Gold’s “social theory of delusions.” 

Marcella Montagnese
Marcella Montagnese

Our recent preprint, “Bayesian Psychiatry and the Social Focus of Delusions,” is a speculative attempt to connect this social turn in the study of delusions to influential work in computational psychiatry that draws on a conception of the brain as a hierarchically structured statistical inference mechanism.

As we note in our article, we are convinced of the importance and explanatory power of this research programme, which we refer to as “Bayesian psychiatry.” Not only is a conception of the brain as a predictive modelling engine utilising sophisticated forms of statistical inference increasingly well-established in cognitive and computational neuroscience, but this perspective offers a battery of important and illuminating conceptual, theoretical, and methodological tools for understanding the dysfunctions and aberrations that underlie psychiatric disorders.

Despite such attractions, we also argue that Bayesian psychiatry is sometimes tacitly aligned with a conception of the brain as a content-neutral, domain-general learning mechanism that is likely to obscure many of the distinctive ways in which the human mind can break down and malfunction. To illustrate this, we explore some of the most influential attempts to understand psychosis within this research programme, such as those that postulate aberrations in uncertainty-weighted prediction error minimisation and volatility estimation.

We argue that explanations of psychosis that rely on such domain-general learning differences are unlikely to be able to capture aspects of its highly domain specific phenomenology. For example, the overwhelmingly social themes of clinical delusions cluster in a tiny region of the vast space of possible themes that abnormal beliefs could represent, and it is difficult to see how generic dysfunctions in statistical inference could explain this. 

To address this, we suggest that Bayesian psychiatry might benefit from accommodating the evolved functional specialisations of the human brain. Of course, such functional specialisations are not realised in discrete self-contained anatomical modules at the macroscopic level of brain structures. Nevertheless, we speculate that Bayesian psychiatry will only be successful to the extent that it recognises that the brain’s statistical algorithms operate in the control centre of a unique primate that evolved to navigate a distinct world of opportunities and risks.

Tuesday 11 May 2021

Social Approaches to Delusions (1): The Social Epistemological Conception of Delusion

Today's post is by Kengo Miyazono (Hokkaido University) and it is the first in the series “Social Approaches to Delusions”. Here Kengo talks about his new paper with Alessandro Salice (University College Cork) “Social Epistemological Conception of Delusion” (open access in Synthese).

Kengo Miyazono

The dominant conception of delusion in psychiatry (in textbooks, research papers, diagnostic manuals, etc.) is predominantly epistemic (Broome & Bortolotti 2009). Delusions are almost always characterized in terms of some epistemic notion, e.g., evidence, reasoning, judgment, etc. For instance, DSM-5 characterizes delusions as “fixed beliefs that are not amenable to change in light of conflicting evidence” (italics added: p. 87), and they are said to be “based on incorrect inference about external reality” and “firmly held despite what almost everyone else believes and despite what constitutes incontrovertible and obvious proof or evidence to the contrary” (italics added: p. 819).

There is, however, an individualistic bias in the epistemic conception of delusions in psychiatry; the epistemic conception tends to characterize delusion in terms of individualistic sources of evidence (e.g. perception, reasoning, memory, etc.) rather than social sources of evidence (e.g. testimony, peer disagreement, etc.). DSM-5, for examples, characterizes delusions in terms of a failure of inference, not in terms of a failure of testimony.

The same bias, i.e., the individualistic bias, had been pervasive in philosophical epistemology until recently; the bias consists in thinking of an epistemic agent as “a single individual who undertakes the task [of seeking truth] all by himself/herself, without consulting others” (Goldman and O’Connor 2019). Against this bias, social epistemologists propose an alternative conception of the epistemic agent as someone who “pursue[s] the truth […] with the help of, or in the face of, others” (Goldman and O’Connor 2019).

We endorse the social epistemological turn in philosophical epistemology and claim that a corresponding turn is needed in the study of delusions. It is a turn from the (purely) individualistic study of delusion in which only individualistic sources of evidence (e.g., perception, reasoning) are investigated to the (partially) social study of delusion in which social sources of evidence (e.g., testimony) are also investigated.

Alessandro Salice

My recent paper with Alessandro Salice is intended as an initial step toward such a social epistemological turn in the study of delusions. This paper presents a new model of the etiology of delusions (the “testimonial theory of delusions”) according to which delusions in schizophrenia are partially explained by testimonial abnormalities, including (1) the loss of testimonial interaction with others (“testimonial isolation”) and (2) the discounting of testimonial evidence (“testimonial discount”). Both testimonial isolation and testimonial discount are general tendencies in schizophrenia, caused by social abnormalities characterizing the disorder.

Our project is coherent with some recent papers, including “Bayesian Psychiatry and the Social Focus of Delusions” by Daniel Williams and Marcella Montagnese, “De-Rationalising Delusions” by Vaughan Bell, Nichola Raihani, and Sam Wilkinson, and “Expressivism about Delusion Attribution” by Sam Wilkinson. I share Williams and Montagnese’s skepticism about content-neutral, domain-general Bayesian account of delusion. Testimonial abnormalities might be domain specific and dissociable from general reasoning abnormalities.

I am also sympathetic to the claim by Bell, Raihani, and Wilkinson that alterations to coalitional cognition play important roles in delusion formation process. Testimonial abnormalities might be understood as one of the consequences of alterations to coalitional cognition. And Wilkinson’s expressivism about delusion attribution can fruitfully be combined with the testimonial theory of delusions. A person X’s expressive act of attributing delusions to another person Y can be understood as X’s reaction to (among others) testimonial abnormalities that are exhibited by Y.

Tuesday 4 May 2021

Political Epistemology

This post is by Michael Hannon and Elizabeth Edenberg. Here they present their new book, Political Epistemology (published by Oxford University Press in May 2021). The following authors have contributed to the book: Elizabeth Anderson, Kristoffer Ahlstrom-Vij, Jason Brennan, Quassim Cassam, Thomas Christiano, Elizabeth Edenberg, David Estlund, Alexander Guerrero, Michael Hannon, Jennifer Lackey, Michael P. Lynch, Fabienne Peter, Jeroen de Ridder, Regina Rini, Jennifer R. Steele, Robert B. Talisse, and Briana Toole.

As current events around the world have illustrated, epistemological issues are at the center of our political lives. It has become increasingly difficult to discern legitimate sources of evidence, misinformation spreads faster than ever, and the role of truth in politics has allegedly decayed in recent years. It is therefore no coincidence that political discourse is currently saturated with epistemic notions like ‘post-truth,’ ‘fake news,’ ‘truth decay,’ ‘echo chambers,’ and ‘alternative facts.’ These issues are part of a rapidly growing area of research called ‘political epistemology.’

The term ‘political epistemology’ only recently entered the academic lexicon, but this newly thriving field has old roots. In the Republic, Plato attacked the epistemic merits of democracy in favor of ‘epistocracy’, or rule by the knowers. In On Liberty, John Stuart Mill touted the epistemic benefits of deliberation for citizens; in Considerations on Representative Government, Mill advocated for plural voting for those with more education in order to improve the quality of political decisions. 

Elizabeth Edenberg

In “Truth and Politics”, Hannah Arendt analyzed the relationship between truth and political freedom. In Political Liberalism, John Rawls put the question of deep and persistent disagreements among citizens at the center of his political inquiry, ultimately arguing that cooperation across disagreements requires setting aside debates about the truth of particular views and instead adopting an agnostic epistemological position.

While scholars have been interested in topics at the intersection of political philosophy and epistemology at least since Plato, the past few years have witnessed an outpouring of new research in this area. For example, new work has been published on propaganda, fake news, political disagreement, conspiracy theories, voter ignorance, climate change skepticism, the epistemic harms of echo chambers, the epistemic merits of (and challenges to) democracy, and intellectual virtues and vices in politics. This rush of interest was largely sparked by the UK Brexit vote and the election of Donald Trump, but the themes that motivate this new research are deeper and more philosophical.

Michael Hannon

Our new book brings together leading political philosophers and epistemologists to explore ways in which the analytic and conceptual tools of epistemology bear on political philosophy, and vice versa. It is organized around three broad themes: truth and knowledge in politics; epistemic problems for democracy; and disagreement and polarization. This book investigates topics such as: the extent and implications of political ignorance, the value of democratic deliberation, the significance of epistemic considerations for political legitimacy, the epistemology of political disagreement, identity politics, political bullshit, and weaponized skepticism.


A premise underlying this collection of work is that, beyond a certain point, progress on certain foundational issues in both political philosophy and epistemology cannot be achieved without sharing insights across fields. By bringing political philosophers into conversation with epistemologists, this volume promotes more cross-pollination of ideas while also highlighting the richness and diversity of political epistemology as a newly emerging field. Our hope is that through careful analysis of the philosophical issues underlying contemporary political challenges, we can identify constructive paths forward.

Please note: There will be a virtual book launch on 20th May, 5-7pm (UK time). To register for the Zoom details, please visit this page where you also find a full schedule of the event. All welcome.