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.

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.

On the basis of clinical literature, the authors hypothesized that individuals with borderline personality disorder (BPD) would show biased information processing when they were exposed to negative affective stimuli of a particular type. Individuals with BPD and controls were tested using a directed forgetting paradigm. Study participants were exposed to 3 types of words (borderline, neutral, positive) and were cued to either remember or forget each word as it was presented. There were no group differences on a free recall task for words in the remember condition. However, participants with BPD recalled significantly more of the borderline words from the forget condition than did controls. In other words, borderline participants remembered borderline words that they were instructed to forget. These results may be consistent with enhanced encoding of salient words and perhaps related themes in BPD individuals.

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If these results can be replicated in a more representative community sample, this 2-stage method might substantially reduce the number of persons who needed to be interviewed in a major epidemiological study of PDs, with little or no loss in diagnostic accuracy, while presumably lowering the cost of such an investigation.