Confirming the latent structure and base rate of schizotypy: A taxometric analysis.

Abstract

Meehl's (1962, 1990) model of schizotypy and the development of schizophrenia implies that the structure of liability for schizophrenia is dichotomous and that a "schizogene" determines membership in a latent class, or taxon (Meehl & Golden, 1982). The authors sought to determine the latent structure and base rate of schizotypy. They applied Meehl's (1973; Meehl & Golden, 1982) MAXCOV-HITMAX taxometric analytic procedures to a subset of items from the Perceptual Aberration Scale (PAS; Chapman, Chapman, & Raulin, 1978), a prominent psychometric index of schizotypy, derived from a randomly ascertained nonclinical university sample (N = 1,093). The results, in accordance with Meehl's conjectures, strongly suggest that schizotypy, as assessed by the PAS, is taxonic at the latent level with a general population taxon base rate of approximately .10.

Taxometric Investigation of PTSD: Data From Two Nationally Representative Samples

“…Specifically, several types of psychopathology, particularly those that are associated with strong biological or environmental influences, have been found to be taxonic. For example, discrete categories have been indicated with regard to schizotypy ( [Korfine and Lenzenweger, 1995] and [Lenzenweger and Korfine, 1992] ), bulimia nervosa (Gleaves et al, 2000), endogenous depression (Haslam & Beck, 1994), and pathological dissociation ( [Waller et al, 1996] and [Waller and Ross, 1997] ). Thus, any attempts to refine psychiatric nosology should not be based on preconceived, or even "expert," notions regarding the categorical or dimensional nature of psychopathology.…”

Additional support for the cognitive model of schizophrenia: evidence of elevated defeatist beliefs in schizotypy

“…Future studies should seek to replicate these findings with alternative working memory tasks in non-college samples and explore the potential relationships between defeatist performance beliefs and other areas of cognition that might be DEFEATIST BELIEFS IN SCHIZOTYPY 16 impaired in schizotypy, such as affectively-valenced cognitive performance [30] or metacognition [49]. Further, research has shown that only approximately 10% of those with schizotypy will go on to develop full-blown psychosis [50]. Thus, a more specific test of the model may involve examining whether those with schizotypy who go on to develop psychosis have decreased neurocognition, elevated defeatist beliefs, and social and occupational problems prior to their onset of psychosis.…”

The dimensional structure of the Wisconsin schizotypy scales: Factor identification and construct validity

“…The predominately European notion of schizotypy, as espoused by Claridge, 54 considers schizotypy to be a normal dimension of personality (fully dimensional model), while the predominately North American conceptualization of schizotypy, as set forth by Meehl,8 considers schizotypy to represent the expression of a pathological process of neurodevelopment that is taxonic in nature. Lenzenweger and Korfine 55 and Lenzenweger et al 56 have used taxometric methods and finite mixture modeling to support the notion of a schizotypic taxon. 55,56 However, both the North American and European conceptualizations are consistent with a multifactorial structure for schizotypy in which schizotypic traits are distributed across continua of increasing severity.…”