Deluded by Experience

Lead Research Organisation: University of Birmingham
Department Name: School of Philosophy Theology & Religion


Our beliefs shape our understanding of the world and our success or failure in interacting with it. To that end, our beliefs are sensitive to evidence and are supposed to be true. When things go seriously wrong and we become prey to delusions, it is natural to try to identify errors present in belief formation and evaluation which might help us understand why things have gone so wrong. Monothematic delusions are a particularly interesting case because subjects have delusions about a specific subject matter (hence 'monothematic'), while otherwise being able to form and evaluate beliefs normally.
Philosophers and psychologists have pioneered a two-factor approach to understanding these beliefs, which identifies specific types of anomalous experience that engender the delusion (factor one), as well as clinically significant errors in belief formation and evaluation (factor two). Our research will reveal that there is no need to posit a second factor. The anomalous experiences people with delusions undergo are far more significant than has been supposed: the specific nature of the experience settle the delusions into which subjects fall, to which they respond, roughly, as normal subjects would. There is no need, we say, to suppose that people with delusions form and evaluate their beliefs differently from subjects without delusions.

For example, in Capgras delusion subjects believe that a loved one has been replaced by an imposter. They do not have the affective response usually associated with looking at their loved one, and so there is an experience of absence. We want to defend an account of how people come to believe very bizarre things such as this, which focuses on these strange experiences and resists appeal to clinically abnormal reasoning. We argue that the way in which people with delusions reason, from their highly anomalous experience to their very bizarre belief, is normal. To say that the reasoning is normal is not to say that it is rational. Healthy subjects reason in all sorts of irrational ways - it is normal to be irrational! Just as conspiracy theorists, horoscope advocates, and some religious believers have some strange belief-forming practices, so too do people with delusions who face strange experiences, which their resulting delusions help to explain. We do not need to posit special kinds of irrationality to explain delusional belief.

We will investigate how our work on delusional belief interacts with philosophical work on perceptual experience and the nature of belief. Some philosophers in the former area have argued that hallucinatory experiences lack phenomenal character (which is to say, there's nothing it feels like to undergo them). We think that philosophers attracted to this view of hallucinations cannot accept a theory of delusion that appeals to them for, at least, an important class of monothematic delusions (those with positive hallucinatory content as opposed to experience of absence). As for the nature of belief, it is commonplace to think that belief is connected to truth. This is demonstrated by the lack of control we have over our beliefs. Although we can imagine things we do not take to be true - which the world of novels, artworks, and movies make use of - we cannot believe things we do not take to be true. Facts like these have led some philosophers to claim that all beliefs aim at truth. We will explore whether delusional beliefs are linked to truth in this way. If they are not, then perhaps we need to reorient our theory of belief, and if they are so truth-aimed, why do they get things so wrong?

Our research into monothematic delusion will have a natural extension into other areas of highly specific, apparently rationally resistant beliefs. Human subjects are trapped by salient experiences into beliefs it is hard for them to give up. The proper understanding of this has wide implications and, indeed, considerable relevance in the current political and intellectual climate.

Planned Impact

The current two-factor orthodoxy insists that people with delusions have a clinically significant failure in belief formation and evaluation as well as anomalous experiences. By contrast, we place the emphasis on the anomalous experiences and consider subjects with monothematic delusions as not needing to have any failure of reasoning. Although our work will be theoretical, it nevertheless lends itself to non-academic impact. Impact will mainly arise from our work on delusion formation - rather than the wider questions concerning the nature of experience and belief - and can be divided into two strands: public understanding and discourse, and engagement with mental health practitioners. Our long-term ambitions are to de-stigmatise mental health conditions, increase public awareness of delusions, and enhance practitioner understanding of how the mind works in order to benefit service users; this project and its impact pathways will help work towards these ambitions.

Public discourse
Our account of delusional belief may destigmatize those mental health conditions for which monothematic delusion are a symptom. By moving away from the idea that people with these beliefs have seriously flawed reasoning, we hope to generate further understanding of why people become delusional, which does not rest upon a rather negative and stigmatizing view of delusional cognition.

We will run at least six public engagement events over the course of the 30-month project (including three school workshops) to engage the public in thinking about the intensity of strange experiences, and how even ordinary people reason in non-ideally rational ways (particularly when undergoing such experiences). We will run events for:

1. University of Birmingham's Arts and Science Festival (Spring 2021 or 2022)
2. Einstein's Garden at the Green Man Festival in 2021 (pending successful application) - the stall will be interactive, focusing on perceptual illusions, as well as quick (and often failed) reasoning tasks.
3. Being Human Festival 2021 or 2022 - we will apply to run an unfunded event (since funding is part of our budget for this application), which would be interactive and free to attend.
4. University of Birmingham School's Philosophy Club - we will hold three interactive sessions at the school over the course of the project, which will be divided neatly into delusion, belief, and perception.

Other public engagement activities will be undertaken as and when the opportunity arises.

The beneficiaries of these events will be the wider public who may well be dealing with people with monothematic delusions, and the media who discuss these issues. We are aiming for heightened awareness of the issues that individuals like these, and their carers, face, for example living with the intensity of strange experiences. Another beneficiary will be media coverage, which will be given a more precise framework for thinking about issues in this area.

Engagement with practitioners
We will run two workshops in Birmingham during Mental Health Awareness week (mid-May 2021 and 2022) for practitioners and service users. Our Project Partner (Headway Birmingham & Sollihull) will be significantly involved in these events. We will discuss with participants the significance of strange experiences, and consider implications for destigmatization and therapeutic treatment. The workshops would be of benefit to service users as they would offer greater understanding and clarity on delusions and reasoning. Practitioners will benefit from the workshops by having a greater understanding so that they may developing strategies within their own practice or organisation. In particular, they may see the benefit in moving away from the idea of people with delusions as clinically bad reasoners, and towards focusing their efforts on understanding patient experience.


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