Aberrant Beliefs and Reasoning

Niall Galbraith

• Publisher: Psychology Press
• Year: 2014
• Print ISBN: 9781848723412
• eBook ISBN: 9781317754817
• Topic: Psychologie
• Subtopic: Psychologie cognitive et cognition

An aberrant belief is extreme or unusual in nature. In the most serious cases these beliefs cause emotional distress in those who hold them, and typify the core symptoms of psychological disorders. Each of the chapters in this volume seeks to examine the role that biases in reasoning can play in the formation of aberrant beliefs.

The chapters consider several conjectures about the role of reasoning in aberrant belief, including the role of the jumping to conclusion bias in delusional beliefs, the probabilistic bias in paranormal beliefs, the role of danger confirming reasoning in phobias, and the controversial notion that people with schizophrenia do not succumb to specific forms of reasoning bias. There are also chapters evaluating different theoretical perspectives, and suggestions for future research.

Aberrant Beliefs and Reasoning is the first volume presenting an overview of contemporary research in this growing subject area. It will be essential reading for academics and students in the fields of human reasoning, cognitive psychology and philosophy, and will also be of great interest to clinicians and psychiatrists.

1

A PSYCHOLOGICAL MODEL OF DELUSIONAL BELIEF

Integrating reasoning biases with perceptual, self-concept and emotional factors

Niall Galbraith and Ken Manktelow

This chapter attempts to integrate the research on reasoning biases in delusional thinking with other psychological theories of delusion, encompassing the self-concept, perceptions, affect and cognition. The first section will reflect briefly on the nature of delusions and will make a proposal for what a complete theory of delusion formation/maintenance should be able to account for. This will be followed by an outline of psychological theories of delusions, culminating in an in-depth review of the role of reasoning biases in delusional beliefs. The literature on reasoning biases in delusions has afforded a range of theories and a major focus will be on integrating these theories along with other psychological explanations into a coherent model of delusion formation/maintenance. Following this, recommendations for future research will be proposed.

Delusional beliefs

Delusions have been described as the sine qua non of psychosis (e.g. Kemp, Chua, McKenna & David, 1997). They are beliefs which, according to the DSM-5 (APA, 2013) are fixed and resistant to change in the face of conflicting evidence. Delusions are also multidimensional and may be assessed in terms of the degree of distress they bring to the believer, level of preoccupation, degree of conviction and action (Garety & Freeman, 1999). Delusions are most commonly thought of as a symptom of schizophrenia (Tandon & Maj, 2008); however they may also feature in a range of other conditions (e.g. depression; Johnson, Horwath & Weissman, 1991).

Although delusions are normally associated with illness, there is an abundance of literature suggesting that delusions and other features of psychosis can be measured on a continuum ranging from the general population through to the clinical population (Freeman, Pugh, Vorontsova, Antley & Slater, 2010; van Os, Linscott, Myin-Germeys, Delespaul & Krabbendam, 2009). The subclinical range of psychotic-like behaviours and experiences is known as schizotypy, and is regarded by many as a multidimensional personality trait (Claridge & Beech, 1995). It is also argued that, although high levels of schizotypy do not equate to mental illness, they may represent a proneness to psychotic breakdown (Claridge & Beech, 1995).

What should a complete theory of delusion formation and maintenance be able to account for?

Consistent with theoretical accounts of delusions (e.g. Coltheart, Menzies & Sutton, 2010; Fine, Gardner, Craigie & Gold, 2007; Freeman, 2007), we identify four major stages of delusion formation/maintenance.

1. Emergence of the delusional idea

There must be a precipitating factor to provide the genesis for the delusional hypothesis. What factors bring about the need for a delusional explanation and why does this delusional hypothesis emerge?

2. Consideration and tentative acceptance of the delusional hypothesis

The delusional hypothesis must then be considered as a viable candidate for belief. Why does a person with delusions not immediately reject an implausible hypothesis as a non-starter for belief?

3. Selection of evidence and full acceptance of the delusional hypothesis

Once the delusional hypothesis has been granted consideration as a potential candidate for belief, in what way is evidence gathered and selected to either 1) support the hypothesis so that it becomes a consolidated belief, or 2) disconfirm the hypothesis so that it is discarded and not adopted as a belief?

4. Maintenance of the belief

Once the belief has been established, how is it maintained and preserved over time?

This chapter will explore the extent to which reasoning biases, in harmony with other psychological factors, can account for these stages in delusional belief. The following section will outline the most influential psychological theories of delusions, encompassing a range of cognitive, perceptual and emotional processes, before a more in-depth review of delusional reasoning is undertaken.

Psychological theories of delusions

Aberrant perceptions

Maher (1974, 2005) posits that delusions are formed from patients’ attempts to explain anomalous perceptual experiences. Crucially, Maher initially argued that it is not faulty reasoning which leads to delusional beliefs but rather faulty perceptions which taint the normal reasoning process. The notion that unusual perceptual experiences can stimulate delusional-type beliefs has empirical support. For example, hypnotically induced deafness (Zimbardo, Andersen & Kabat, 1981) or natural hearing loss in the elderly (e.g. Cooper, Kay, Curry, Garside & Roth, 1974) can lead to paranoid beliefs in non-patients. Furthermore, delusions and hallucinations commonly co-exist in psychotic patients (Peralta & Cuesta, 1999) and people who are delusion-prone show a reduced ability to predict sensory outcomes from self-generated actions (Teufel, Kingdon, Ingram, Wolpert & Fletcher, 2010).

In spite of the support for Maher’s position, others have failed to replicate the relationship between hearing impairment and delusions (Cohen, Magai, Yaffe & Walcott-Brown, 2004; Östling & Skoog, 2002). Indeed Maher (1999) moved away from a purely perceptual account, later proposing an additional probabilistic reasoning impairment in addition to faulty perceptual processes. Maher’s theory has been extended by Coltheart and colleagues, who propose a two-factor model (e.g. Davies & Coltheart, 2000; Coltheart, Langdon & McKay, 2011). Perceptual anomalies constitute the first factor; the second factor is a deficit in the mechanism of belief revision, which prevents the individual from rejecting the implausible ideas which arise from the perceptual anomaly.

Affect and schemas

Freeman and colleagues’ threat anticipation model (e.g. Freeman, 2007; Freeman, Garety, Kuipers, Fowler & Bebbington, 2002) also acknowledges that hallucinations are central to (particularly persecutory) delusions, but contends that other factors combine in the formation of delusions. In addition to internal hallucinatory experiences, external events such as interactions with other people and negative environmental occurrences may also be precipitating factors in the genesis of delusional ideas. Anxiety strongly predicts delusions in both clinical and non-clinical samples (e.g. Fowler et al., 2006; Freeman et al., 2005; Martin & Penn, 2001) and negative schemas about the self (e.g. I am weak, unloved, vulnerable, etc.) and others (e.g. others are hostile, untrustworthy, nasty, etc.) have strong relationships with paranoia (Fowler et al., 2006; Smith et al., 2006). Other affective states such as worry (Freeman et al., 2013) and depression (e.g. Galbraith et al., 2014) may also exacerbate paranoia. The combination of anxiety and negative schemas is central to the threat anticipation model. In line with Beck’s schema-based cognitive model of anxiety (e.g. Clark & Beck, 2010), the threat anticipation model proposes that negative schemas lead to a biased construal of the self, the world and other people. In addition, anxiety leads to a hyper-vigilance for threat. Negative schemas and anxiety combine then, to leave the individual feeling both personally vulnerable and at risk from malicious others (Fowler et al., 2006). If hallucinations occur in such individuals, their putative causal hypotheses for these experiences may be coloured by negative schemas and anxiety, and thus hallucinations are attributed to sinister causes. Biased data-gathering (Freeman, Pugh & Garety, 2008) or self-referent reasoning (Galbraith, Manktelow & Morris, 2008) may then consolidate these putative delusional hypotheses.

Bentall and colleagues (e.g. Kinderman & Bentall, 1996, 1997) have proposed that persecutory delusions are characterised by a bias to blame other people (as opposed to situational factors or oneself) for negative events. Such a tendency may prime one to formulate persecutory ideas, in which other people are to blame when bad things happen to the self. Bentall and colleagues argue that this bias has a defensive function, as persecutory beliefs may block out negative self-representations and therefore protect fragile self-esteem. Despite empirical support, there have also been failures to replicate the attributional bias in paranoid individuals (e.g. Lincoln, Mehl, Exner, Lindenmeyer & Rief, 2010; Martin & Penn, 2001; Young & Bentall, 1997b). Freeman (2007) contends that a more parsimonious position would be that people with persecutory delusions may sometimes make external attributions but that this need not reflect a defensive process or an external personalising bias. Indeed some evidence from non-clinical studies (e.g. Galbraith et al., 2014) and from clinical studies (e.g. Barrowclough et al., 2003) supports the view that paranoia is more likely to be negatively related to self-esteem and positively related to depression, thus reflecting a non-defensive account.

Conversely, grandiose beliefs may be strongly linked with positive affect. For example, (Smith et al., 2006) found that such beliefs were associated with strong positive-self schemas but also negative-other schemas. This combination of schemas may increase one’s perceived social standing relative to others (Smith et al., 2006). Contrastingly, others have found grandiose delusions as characterised by less negative schemas, both for the self and for others (Garety et al., 2013). Furthermore, people with grandiose delusions may have a cognitive style which predisposes them to misinterpret both internal and external events as personally relevant and in a way which amplifies positive affect (Knowles, McCarthy-Jones & Rowse, 2011; Mansell, Morrison, Reid, Lowens & Tai, 2007). As Knowles et al. (2007) point out, research which focuses specifically on grandiose delusions is relatively scant, and therefore conclusions about the psychological underpinnings of these beliefs cannot be as confident as those on paranoid ideas, for example.

Theory of mind

Frith (1992) argues that delusions of persecution, reference and misidentification are due to an inability to represent the thoughts, attitudes, beliefs and intentions of others – that is, a poor theory of mind (ToM). A number of studies have reported links between delusions and ToM (e.g. Corcoran, Cahill & Frith, 1997; Gooding & Pflum, 2011; Taylor & Kinderman, 2002). However, many studies have failed to observe associations between ToM and delusions or paranoia (e.g. Blackshaw, Kinderman, Hare & Hatton, 2001; Greig, Bryson & Bell, 2004), or have instead found associations between ToM and other features of psychosis, such as negative symptoms or thought disorder (Kelemen et al., 2005; Pickup & Frith, 2001). The ToM deficit might reflect a generic mental illness factor (Corcoran et al., 1997) or a cognitive deficit (Bora, Yücel & Pantelis, 2009; Langdon et al., 1997). The ToM account is intuitively appealing as it can explain why some people misconstrue the intentions of others (potentially leading to ideas of persecution), but despite some good empirical support, the data are somewhat inconsistent and the deficit may not be specific to delusions.

This section has provided an overview of what are currently the most widely cited psychological theories of delusions. The next section will examine the evidence on delusional reasoning.

Reasoning in delusions

The following section will review literature on delusional reasoning biases. In this context, the term ‘bias’ is taken to mean a systematic tendency to respond or behave in a manner which differs from some reference group. The reference group is typically either psychiatric or non-psychiatric controls or, in the case of non-clinical studies, people from the general population who themselves do not score highly on measures of subclinical delusional belief.

The jump-to-conclusio...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• List of illustrations
• List of contributors
• Preface
• Introduction: the role of reasoning in aberrant beliefs
• 1 A psychological model of delusional belief: integrating reasoning biases with perceptual, self-concept and emotional factors
• 2 Prediction-error and two-factor theories of delusion formation: competitors or allies?
• 3 Reasoning and delusions: do people with delusions really jump to conclusions?
• 4 Affect, dual processes and some pertinent questions about delusional reasoning
• 5 Reasoning in schizophrenia
• 6 Paranormal believers’ proneness to probabilistic reasoning biases: a review of the empirical literature
• 7 Danger-confirming reasoning and the persistence of phobic beliefs
• 8 Non-pharmacological treatment targeting cognitive biases underlying delusions in schizophrenia: metacognitive training and therapy
• Index