The 3DPT dimensions S, E, and N: A critical evaluation of Eysenck's Psychoticism model

Abstract

In this article a critical evaluation is given of Eysenck's Psychoticism model. It is argued that in this model two sub‐models can be distinguished, which, contrary to Eysenck's presentation, cannot be regarded as true extensions of each other. With respect to one of these models, the ‚genotypic’︁ P‐model, the theory is criticized in that both schizophrenia and affective psychosis are determined by a common genetic predisposition which can phenotypically manifest itself in variations of P. Instead of this theory, the likelihood is put forward that a high EPQ‐P score, albeit in combination with a high N and a low E score (and notwithstanding the fact that criminals or psychopaths can also obtain high P scores), is (only) related to the schizoid state, and hence, that P seems to be relevant either as a predisposing factor contributing to the development of schizophrenic psychosis, or as a factor on which biological relatives of schizophrenics obtain higher scores on average than normals do. In this respect, Eysenck's theory that the non‐schizoid form of psychopathy can also be found among first‐degree relatives of schizophrenics, and hence, that psychopathy and schizoidia are genetically related, is also criticized. Furthermore, it is argued that Eysenck's EPQ‐P scale is not optimal for measuring those traits of the schizoid personality which are independent of N and/or E. Both arguments regarding the contents of this scale and arguments with respect to the demonstrated lack of invariance of the EPQ‐P factor are adduced to support this statement. Thus, an alternative scale for measuring ‚P’︁ (labelled S or Insensitivity) was designed by us. The S‐scale is based on literature concerning the schizoid state and reflects the results of a series of principal components analyses of (potential) S items, together with N and E items, put into execution with the intention of investigating the invariance of the S factor (and of E and N) with respect to six sample and other parameters. These investigations were carried out on a large, representative sample of the Dutch population. Additional investigations were carried out concerning the reliability and validity of the three newly formed scales. The results of these investigations turned out to be very satisfactory or, in some respects, at least promising. Finally, in this article, comments are made on the nature of the S factor, comparing this dimension with both Eysenck's P factor and the dimensions Agreeableness and Conscientiousness, as proposed, for instance, in McCrae and Costa's version of Nor‐man's 5‐factor model. As against P, the S or Insensitivity factor seems to be only (negatively) related to Agreeableness and not to Conscientiousness. It is also argued that this finding seems to be in accord with the supposed schizoid nature of S and the criticisms levelled at Eysenck's EPQ‐P scale.

Psychometric appraisal of Eysenck's revised Psychoticism scale: a cross-cultural study

“…Since some original P items had factor loadings that do not fulfil the described inclusion criteria (Van Kampen, 1993), around nine items out of 32 would be dropped leaving a new P scale with a very similar length to ours.…”

The P-psychopathy continuum: Facets of Psychoticism and their associations with psychopathic tendencies

“…Their behavioral deficits are reflected in impulsivity, recklessness, and antisociality (Eysenck, 1992). Whilst the P-continuity hypothesis for schizophrenia has been directly tested across normal, forensic, and clinical populations (Eysenck, 1992; but see also Van Kampen, 1993), the P-psychopathy relationship has not been investigated to the same extent and little is known of the role of P in predicting psychopathic tendencies in normal populations (Lynam & Derefinko, 2006). Nevertheless, high levels of P have been linked to deficits similar to those seen in psychopathic populations (Corr, 2010).…”

The 5-Dimensional Personality Test (5DPT): Relationships With Two Lexically Based Instruments and the Validation of the Absorption Scale

“…Eysenck & Eysenck, 1969), but also to constitute a diagnostic dimensional framework that compares favorably with psychiatric classification (e.g., Eysenck, 1970). Yet, several scholars have criticized the PEN model, particularly with respect to P. Although some of these criticisms might not be wholly justified (see Van Kampen, 1993), the P part of Eysenck's PEN model has indeed been found to suffer from several shortcomings.…”

“…Thus, recognizing the differences between the two P models, a genotypic factor similar to the P dimension as measured by the Eysenck Personality Questionnaire (EPQ; S. B. G. Eysenck & Eysenck, 1975) was postulated, albeit now standing for the phenotypic expression of a genetically based predisposition toward antisocial conduct in schizophrenia and related spectrum disorders (Van Kampen, 1993). This alternative dimension, which was based on descriptions of personality deviance (unrelated to E or N; see later) that might occur prior to the onset of schizophrenia or among biological relatives of schizophrenic patients (e.g., Slater, 1953), was termed S or Insensitivity.…”

“…Elsewhere (see Van Kampen, 1993, 1996, 1997, we have described these deficiencies in greater detail, but, essentially, it can be stated that (a) the genetic overlap of schizophrenia and manic-depression as postulated by Eysenck appears to be nonexistent (Cardno, Rijsdijk, Sham, Murray, & McGuffin, 2002;Kendler & Gardner, 1997) or at most limited to schizophrenia and unipolar depression (e.g., Maier, Hallmayer, Minges, & Lichtermann, 1990); (b) contrary to Eysenck's claim, only the schizoid (and not the "classical") form of psychopathy belongs to the group of spectrum disorders genetically associated with schizophrenia (e.g., Heston, 1970); (c) patients with schizophrenia, unipolar depression, or manic disorder do not share the same premorbid personality traits believed by Eysenck to be associated with P (see, e.g., Bleuler, 1972;Lauer et al, 1997); and (d) in opposition to Eysenck's assertion, the testing of the P theory by means of proportionality analysis has not demonstrated the existence of a phenotypic continuum ranging from normality to psychosis because of the mixing up of two conceptually different P models, the phenotypic and the genotypic model (Van Kampen, 2009).…”