Examination of the factor structure of the Schizotypal Personality Questionnaire (SPQ) among British and Trinidadian adults

Much debate in schizotypal research has centred on the factor structure of the Schizotypal Personality Questionnaire (SPQ), with research variously showing higher-order dimensionality consisting of two to seven dimensions. In addition, cross-cultural support for the stability of those factors remains limited. Here, we examined the factor structure of the SPQ among British and Trinidadian adults. Participants from a White British sub-sample (n = 351) resident in the UK and from an African Caribbean sub-sample (n = 284) resident in Trinidad completed the SPQ. The higher-order factor structure of the SPQ was analysed through confirmatory factor analysis, followed by multiple-group analysis for the model of best-fit. Between-group differences for sex and ethnicity were investigated using multivariate analysis of variance in relation to the higher-order domains. The model of best-fit was the four-factor structure, which demonstrated measurement invariance across groups. Additionally, these data had an adequate fit for two alternative models: a) 3 factors and b) a modified 4-factor. The British sub-sample had significantly higher scores across all domains than the Trinidadian group, and men scored significantly higher on the disorganised domain than women. The four-factor structure received confirmatory support and, importantly, support for use with populations varying in ethnicity and culture.

Associations between schizotypy and belief in conspiracist ideation

Previous studies have reported associations between conspiracist ideation and domain-level facets of schizotypy, but less is known about associations with lower-order facets. In the present study, 447 adults completed measures of conspiracist ideation and the Schizotypal Personality Questionnaire (SPQ), consisting of nine subscales grouped into four domains. Results of a multiple regression showed that two domains of the SPQ significantly predicted conspiracist ideation, but multicollinearity was a limiting factor. In a second regression, we found that the subscales of Odd Beliefs or Magical Thinking and Ideas of Reference significantly predicted conspiracist ideation, without any multicollinearity constraints. We interpret these results as implicating two specific lower-order facets of schizotypy in belief in conspiracy theories. We further contrast the present results with previous studies indicating associations between conspiracist ideation and paranormal beliefs.