What Does the P Scale Measure?

Abstract

Beginning with the hypothesis that ‘there exists a set of correlated behaviour variables indicative of predisposition to psychotic breakdown, demonstrable as a continuous variable in the normal propulation, and independent of E and N’ (H. Eysenck and S. Eysenck, 1968), the Eysencks have been concerned to develop a questionnaire scale to measure such a variable. From an initial pool of potential items, hypothesized to be related to psychoticism, several factor analyses of adult responses have been conducted to obtain a small group of items measuring a factor orthogonal to the factors of neuroticism and extraversion, and these items have been called the Psychoticism or P Scale (H. Eysenck and S. Eysenck, 1968; S. Eysenck and H. Eysenck, 1968; S. Eysenck and H. Eysenck, 1972). The same arguments have been applied to children, and a similar set of items have been assembled to measure this variable (H. Eysenck and S. Eysenck, 1971; H. Eysenck, G. Easting and S. Eysenck, 1971; S. Eysenck and H. Eysenck, 1969).