The taxonicity of schizotypy: A replication.

Abstract

P.E. Meehl's model (1962, 1990) of schizotypy and the development of schizophrenia implies that the structure of liability for schizophrenia is dichotomous, hypothesizing that a "schizogene" determines one's membership in a latent class (or taxon; P.E. Meehl & R. R. Golden, 1982). The present study sought to replicate earlier findings concerning the taxonic latent structure and general population base rate of schizotypy (M. F. Lenzenweger & L. Korfine, 1992). P.E. Meehl's (1973; P.E. Meehl & R. R. Golden, 1982) MAXCOV-HITMAX taxometric analytic procedures were applied to a subset of items from the Perceptual Aberration Scale (PAS; L. J. Chapman, J. P. Chapman, & M. L. Raulin, 1978), a prominent psychometric index of schizotypy, derived from a new randomly ascertained nonclinical university sample (N = 1,646). Consistent with the authors' previous results as well as Meehl's conjectures, the data strongly suggest that schizotypy, as assessed by the PAS, is taxonic at the latent level with a low general population taxon base rate (i.e., < .10). Moreover, individuals falling within the putative schizo-taxon underlying the PAS present greater levels of schizotypic phenomenology than nontaxon members. The taxometric analysis of the psychological trait of femininity also reveals that the MAXCOV-HITMAX procedure can detect a latent dimension, when one is hypothesized to exist, and the procedure does not appear to generate "spurious" evidence for taxonicity as a function of the psychometric format (e.g., true-false) of the data under analysis. The statistical implication of a taxonic entity occurring at a low base is discussed with respect to results obtained using the MAXCOV-HITMAX technique.

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.…”

“…Taxometric procedures have a long history in the literature (e.g., Meehl, 1973) and have recently gained popularity as their utility has become increasingly recognized. Researchers have used these procedures to examine the latent structure of numerous forms of psychopathology, including schizotypy (e.g., Korfine & Lenzenweger, 1995), bulimia nervosa (Gleaves, Lowe, Snow, Green, & Murphy-Eberez, 2000), and depression (e.g., [Ruscio and Ruscio, 2000] and ). With regard to PTSD, only one taxometric investigation is available in the published literature.…”

Schizotypy From a Developmental Perspective

“…However, unlike the so-called fully-dimensional perspective referred to above, these models consider that despite there being phenomenological continuity between traits and symptoms, the latent liability (eg the genetic susceptibility) is not continuously distributed in the population, which yields a group of liable individuals (a taxon) which is qualitatively different from the rest (ie structural discontinuity). The investigation of the structure of schizotypy with taxometric analyses is a convulse topic given its methodological complexity 16 and has raised mixed findings, with some studies supporting 17,18 and others not [19][20][21] the existence of a schizotypy or schizotypal personality disorder taxon.…”

Taxometric analyses of sexual orientation and gender identity.

“…They do suggest, however, that some dichotomous factor affects the domain of social anhedonia, justifying and potentially helping to direct attempts to identify a critical factor accounting for "schizotypy." Evidence for taxa also exists for self-monitoring (Gangestad & Snyder, 1985;see 'also von Davier & Rost, 1997), Type A (Strube, 1989), schizotypy (more broadly; Tyrka et al, 1995), perceptual aberation (Korfine & Lenzenweger, 1995;Lenzenweger & Korfine, 1992), psychopathy (Harris, Rice, & Quinsey, 1994), and dissociative disorder (Waller, Putnam, & Carlson, 1996).…”