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Measuring Schizotypy Personality through Questionnaires

The Psychometric Detection of Schizotypy: Do Putative Schizotypy Indicators Identify the Same Latent Class?

Horan, WP; Blanchard, JJ; Gangestad, SW; Kwapil, TR.
Journal of Abnormal Psychology. 2004 Aug Vol 113(3) 339-357

There is a lot of research being done to identify personalities of individuals prone to the development of schizophrenia, so that early intervention is possible. One type of personality that is involved with a risk for schizophrenia is called schizotypy. People with this type of personality have features known as anhedonia (difficulty experiencing pleasure), cognitive slippage, ambivalence (uncertainty) and interpersonal aversiveness (preference to be alone). One theory is that individuals with some schizophrenia genes (schizotaxia) will have a necessary but not sufficient condition for the development of schizophrenia. In other words, they are members of a latent class (or taxon) within the general population who carry the genes but do not express schizophrenia fully. Instead they may show schizotypal personality traits. Some of the questionnaires that measure schizotypy include the Perceptual Aberration Scale (PAS), Magical Ideation Scale (MIS) and the Revised Social Anhedonia Scale (RSAS).

This study argues that it is unclear whether all 3 of these questionnaires are able to identify a common group of individuals who constitute the same (presumably genetically determined) latent group. So, the researchers used statistics to look at the independent and joint latent structures of the RSAS, MIS, and PAS in students from public universities. They wanted to see if the positive and negative traits in these questionnaires are able to identify a common group in the general population. They found that these 3 questionnaires, that were thought to tap the same latent class that was assumed to be schizotypy, actually do not share this property. They suggest that this might explain why there have been differences in studies that have used these questionnaires since they actually measure different causal processes within the clinical syndrome of schizophrenia or psychosis proneness more generally. Further research is needed to look at the characteristics and outcomes of individuals who actually have the taxa that is measured by both the RSAS and the PAS and/or MIS, so that we can understand what their roels are in schizophrenia. The authors argue that it doesn't make sense to use these questionnaires to idenify a common latent class of people.

This research was supported by Grant MH-51240 from the National Institute of Mental Health.

Click here to find this article on PubMed

Author: Farzin Irani