The latent structure of schizotypy: Looking back and moving forward

Investigations into the latent population structure of schizotypy have largely revealed the existence of a two-class structure, consistent across psychometric and endophenotypic indicators. Such findings provide, at face value, strong support for Meehl’s schizotypy-schizotaxia model, though limitations to this research constrain the opportunities for conclusions to be drawn and implications realised. In the present research, the reliance on a narrow set of psychometric measures and the absence of class validation are explicitly addressed. Undergraduate students (n = 500) completed a range of psychometric, neurocognitive, and behavioural measures and tasks. Across four studies, the latent structure underlying these psychometric and objective indicators was investigated using maximum covariance analysis and consistency tests. In Study 1 a latent general schizotypy class was identified following analysis of Schizotypal Personality Questionnaire item scores (base rate .18). Class membership was significantly associated with family history of psychosis and the frequency of risk alleles. An interpersonal (negative) features class was also identified (base rate .14). In Studies 2 and 3, objective indicators, selected based on their association with schizophrenia liability, did not reveal consistent evidence of latent taxonicity. The combination of objective and psychometric indicators in Study 4 indicated latent continuity also. The results reported here provide evidence of a distinction between schizotypal and non-schizotypal individuals, when assessed at the level of phenotypic presentation. Failure to reveal this structure with multimodal indicators, however, has implications largely for the ways in which latent structure is investigated