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4.2.4,1 Delusion-like beliefs (DLB)

Delusion-like beliefs were based on the major thematic delusions found in mainstream psychotic and neuropsychiatric conditions. Items addressing DLB were adapted from DSM-IV-TR (APA, 2000), existing clinical measures (Bebbington &

Nayani, 1995; Peters, Joseph & Garety, 2004; Robins et al., 1998; Sheehan et al., 1988) and relevant examples from the cognitive neuropsychological research literature (Bell, Halligan & Ellis, 2006b; Davies & Coltheart, 2000; Ellis & Young, 1990). To ensure coverage o f a broad range, items were chosen to be representative of each delusional theme. These included five questions relating to the major subtypes of delusional disorder (APA, 2000); one item each for persecutory, erotomanic and grandiose ideas, and two different aspects of the somatic subtype (body dysmorphia and parasitosis). Two other items assessed the non-bizarre ideas of reference and nihilistic beliefs.

In addition, ten questions specifically addressed bizarre themes (as defined by DSM-IV). This type of delusion has been comparatively under-researched in non- clinical samples, due to the assumption that the bizarreness of these ideas makes them unlikely to be found in general populations. However, given the emphasis on the content of beliefs for diagnosing schizophrenia (with different requirements depending on the bizarre/non-bizarre distinction), it was valuable to determine the degree to which bizarre beliefs are present. Bizarre items covered beliefs of external control, thought insertion, Capgras syndrome, Cotard syndrome, Fregoli syndrome, reduplicative paramnesia (of both person and place), mirrored-self misidentification, subjective doubles and somatoparaphrenia.

4.2.4.2 Paranormal and religious beliefs

Rice (2003) drew a distinction between classic paranormal beliefs (e.g., in ESP) and religious beliefs, often considered to be a subset of paranormal beliefs. In terms of the relationship between these beliefs, there exist two opposing hypotheses in the literature. One predicts a negative relationship between these two, given that paranormal beliefs may fulfil the spiritualist needs of those without religion (Emmons

& Sobal, 1981) and/or because mainstream religious doctrines contribute to rejecting such beliefs (Sparks, 2001). On the other hand, a positive relationship between these two types of beliefs could be expected, given that both consist of “beliefs in physical, biological or psychological phenomena that feature fundamental or core ontological properties of another ontological category” (Lindeman & Aamio, 2006, p. 586-7). In other words, both relate to beliefs in the existence of phenomena that cannot be explained by current scientific theories.

Indeed, studies have found support for both (contradictory) predictions, which might in part be explained by the lack a single well-validated measure of religiousness (or an agreed definition of paranormal beliefs). For example, Orenstein (2002) found that church attendance was related to content-specific religious beliefs but not to certain classic paranormal beliefs. Similarly, Thalboume and O ’Brien (1999) tested three different religiosity scales against a measure of paranormal beliefs (the Australian Sheep-Goat Scale: Thalboume & Delin, 1993), and found a close to significant negative correlation, no correlation and a significant positive correlation between the different scales. Finally, Tobacyk and Milford (1983) found that religious beliefs were positively correlated with beliefs in precognition and witchcraft, but uncorrelated with beliefs in telepathy or extraordinary life forms.

The relationship between these two sets of belief used in the CBQ was therefore investigated, and will be outlined further in the following section describing the CBQ’s psychometric credentials. As the paranormal and religious beliefs did indeed form a reliable scale, these beliefs will be described together.

Questions concerning paranormal and religious beliefs were constructed from reviews of published market research polls (Gallup & Newport, 1991; Rice, 2003;

Taylor, 2003) and paranormal belief measures (Eckblad & Chapman, 1983;

Thalboume & Delin, 1993; Tobacyk & Milford, 1983). Following Lindeman and Aamio (2006, pp. 586-7), this group of beliefs was defined as “beliefs in physical, biological or psychological phenomena that feature fundamental or core ontological properties of another ontological category” (e.g., ‘Do you believe that some people communicate with the dead?’).

4.2.4.3 Societal/cultural

Finally, the last group of beliefs were classified as societal/cultural beliefs (of which paranormal and religious beliefs can, depending on one’s viewpoint, be considered a subset) and included scientific, political and moral items (e.g., ‘Do you believe that humans cause significant global warming?’). Importantly, the large number of non- clinical belief questions, while interesting in their own right, were strategically inserted to provide a balanced context that encouraged participants to respond more truthfully and allowed exploration of the links between delusion-like beliefs and other belief types.

4.2.4.4 Anomalous experiences

In addition, 8 anomalous experience items were included, of which 4 items focused on common paranormal experiences, selected from reviews of published market research polls (Gallup & Newport, 1991; Rice, 2003; Taylor, 2003) and measures o f paranormal phenomena (Eckblad & Chapman, 1983; Thalboume &

Delin, 1993; Tobacyk & Milford, 1983), to ensure that items comprised a wide range of experiences. In addition, two items (relating to changed feelings towards others and towards objects) were chosen to evaluate specific hypothesised links between anomalous experiences and beliefs (described in Chapter 6). The final 2 items targeted visual and auditory hallucination-like experiences to allow a more direct evaluation of their association with delusion-like beliefs.

Although many more hallucinatory items have been included in some studies (e.g., Laroi & van der Linden, 2005), the number of hallucination-like items is not that dissimilar from those included in several other studies (e.g., Johns et al., 2002, 2004; Verdoux et al., 1998). Moreover, the two clinically related items cover the most common types of hallucinations by modality. Cutting (1990) estimated auditory hallucinations occurred in 55% of participants and visual in 15%. These are also amongst those most commonly associated with psychotic disorder (along with haptic hallucinations: Ohayon, 2000). Moreover, although different versions of the more comprehensive Launay-Slade Hallucination Scale (Launay & Slade, 1981) yield different factor structures, visual and auditory hallucinations remain the two most consistent factors, with others consisting of non-hallucinatory factors relating to vivid thoughts and daydreaming or sleep-related experiences (Laroi & van der Linden, 2005; Morrison et al., 2000; Morrison et al., 2002).

4.2.4.5 Self-appraisals and insight

A final feature of the CBQ was to briefly investigate individual’s self­

appraisals of their beliefs and in particular their collective judgement of the likelihood of holding delusion-like beliefs or hallucination-like experiences. In the CBQ participants are asked to rate the extent to which they consider themselves (a)

‘superstitious (i.e. likely to believe certain events occur through mysterious or magical means)’, (b) ‘a religious person’, (c) ‘likely to believe in things that others do not’

and/or (d) ‘tolerant of people with different beliefs’.