Questionnaire development

The final version of the CBQ was developed following a long iterative process, involving feedback from three earlier pilot versions and a total of 559 participants (see Table 4.3). Each version was reviewed following each pilot and ambiguous or unrepresentative items were revised or removed. As Table 4.3 shows, the majority of revisions involved non-clinical beliefs, although minor grammatical changes to the wording of other items were also made. The major change to DLB items occurred between versions 2 and 3, when three new items (addressing somatoparaphrenia, subjective doubles and nihilism) were added. The final version was therefore very similar to version 3, albeit with minor changes in wording and the addition of 7 new societal/cultural belief items to ensure a balance in the ratio of non- clinical to clinical-like items. The key developments covered by the pilot studies are summarised below. (Full lists of revisions made to the questionnaire items following the pilot studies are presented in Tables (i)-(v) in Appendix III.)

Questions regarding “actual vs. possibility ”

One of the main revisions to the initial scale following piloting the first version on 254 participants was to ensure that questions were consistently framed in a direct format rather than as “potential” or “possibility” judgements (i.e., items were phrased

‘do you believe that people are possessed by evil spirits?’ rather than ‘do you believe that people can be possessed by evil spirits?’ as in the first version). This provided for a better comparison between questions, particularly in the case of the delusion-like belief questions, where it was felt that these should be based on current beliefs, rather than abstract hypothetical judgements or possibilities.

Table 4.3. Participant sample characteristics for the three pilot studies and final large study Pilot 1 254 Open University conference;

University volunteer panel; Pilot 2 119 University volunteer panel Paper and pen Range: 18-48;

Mean = 21.6; Pilot 3 186 First year undergraduates in

psychology DLB: Delusion-like beliefs; PB: Paranormal beliefs; RB: Religious beliefs; SCB: Societal/cultural beliefs; + added; - removed

122

Current vs. lifetime focus

A second main change concerned the format of the questions. Initially participants were requested to answer ‘Do you believe, or have you believed...’. As this tended to emphasise both current and lifetime positions (the latter also involving long term memory), this was changed to ‘Do you believe...’ to emphasise currently held beliefs.

This provides an estimate of the number of people holding the belief at the time of being interviewed rather that depending on past recollections which might involve occasions and periods when they did or did not believe. This also provided for analysis of differences across age groups and in particular to determine whether younger people were more likely to hold delusion-like beliefs, as is the case with delusional ideation (Verdoux et al., 1998).

Personally relevant nature

The major change between versions 2 and 3 (described in Tables (i)-(iii), Appendix III) was that items were now revised to emphasise their personally relevant nature. It was noted that all the delusion-like items except the pair addressing reduplicative paramnesia were personally relevant (e.g. ‘Do you believe that your relatives have been replaced by similar looking people?’), whereas none of the other belief type questions had this personal emphasis. Those items which could be adapted to focus on an individual were changed to increase the similarity between the delusion-like and other questions on the CBQ.

Leading questions

A small revision between versions 2 and 3 attempted to ensure that questions did not appear to lead participants’ responses. This applied particularly to the moral questions, which had previously required individuals to say whether they believed that a statement was right. These were adapted to ask instead whether each statement was right or wrong, with a new answer scale, from ‘Strongly believe it is right’ through to

‘No opinion’ and on through to ‘Strongly believe it is wrong’.

Belief coherence

A main revision to version 3 o f the CBQ was the inclusion of five pairs of beliefs that could be used to directly assess participants’ belief coherence on the assumption that, if beliefs are core personally-relevant propositions that are strongly endorsed, they should show some internal consistency. This reflects the arguments made in Chapter 1, whereby a criterion of ‘belief should be that it is logically coherent with other beliefs held by an individual. The five pairs are described below:

a) If a participant answered believe (at any level) to a question: ‘To what extent do you believe in reincarnation (i.e. that when you die your soul is reborn in another body)?’, it was predicted that they should also answer positively to ‘To what extent do you believe that the soul or spirit survives death?’

b) If a participant responded believe (at any level) to the question: ‘To what extent do you believe that some people communicate with the dead?’, it was expected that they should also answer believe to ‘To what extent do you believe that the soul or spirit survives death?’

c) If a participant answered believe (at any level) to the question: ‘To what extent do you believe that earth has been visited by aliens from other solar systems?’, it was expected that they should also answer believe to ‘To what extent do you believe in extra-terrestrial life?’

d) If a participant responded believe (at any level) to the question: ‘To what extent do you believe that some people are possessed by evil spirits?’, it was expected that they should also answer believe to ‘To what extent do you believe in demons or evil spirits?’

e) If a participant answered believe to either of the questions: ‘To what extent do you believe in the theory of evolution?’ or ‘To what extent do you believe that humans share a common ancestor with apes?’, then it was expected that they should answer believe to the other.

These pairs were also used to further investigate the web of belief hypothesis (Quine

& Ullian, 1970), and to investigate the assumption that all beliefs held by an individual are consistent with each other (see Chapter 7).