Principal components analysis of the Schizotypal Personality Scale (STA) and the Borderline Personality Scale (STB)

The Schizotypal Personality scale (STA) is a popular measure of schizotypal personality. The Borderline Personality scale (STB) is a rarely used measure of borderline personality. Together they comprise the Schizotypal Traits Questionnaire, as described by Claridge and Broks [Claridge, G., & Broks, P. (1984). Schizotypy and hemisphere function: I. Theoretical considerations and the measurement of schizotypy. Personality and Individual Differences, 5, 633–648]. The present article reports Principal Components Analyses, followed by Promax rotation, of the tetrachoric correlation matrix of the items of each of the two scales. The STA analysis suggested four factors labelled Magical Thinking, Unusual Perceptual Experiences, Paranoid Suspiciousness and Isolation, and Social Anxiety. This factor structure is compared with previous factor analytic studies of the same scale. Factor analysis of the STB has not been previously reported. Two factors were produced and formed the basis for two correlated sub-scales labelled Hopelessness and Impulsiveness. Separate analyses for females and males provided substantial support for the full-sample analyses. Alpha-coefficients, sex differences and correlations with age are provided for the various scales and sub-scales.