The Measurement of Psychoticism: a Study of Factor Stability and Reliability

An investigation is reported into the measurement of the personality dimension P (psychoticism), which has emerged from factorial and other empirical studies as a third dimension additional to E (extraversion) and N (neuroticism.) Large groups of normal men and women, and of male and female students, were administered an inventory containing 106 potential P, E and N items, and the results analysed in detail. It emerges that P, E and N factors are found, as predicted, in the factor analysis of the data; that reliable scales can be constructed from the available items for P; and that the factors found are relatively invariant from one sex to the other, and from one sample to others. It appears that N and P are not entirely independent, but correlate to a moderate extent. It is suggested that P might be a personality variable of interest in connexion with many experimental investigations; that it might determine differential performance, either alone or in conjunction with E and/or N; and that experimental studies of P in normal subjects might throw much needed light on the nature and meaning of psychoticism as a personality variable.