Abstract
A same-day administration of the Millon Clinical Multiaxial Inventory and the Eysenck Personality Questionnaire to 325 male and 531 female clients allowed study of the psychometric properties of both instruments. Clients scoring low on Eysencks' Psychoticism, Extraversion, Neuroticism, and the Lie scale significantly differed from their high-scoring peers on many mean scores for the 20 Millon scales. Midrange scorers on the four Eysenck scales differed from extreme scorers on some Millon scales. A principal axis factor analysis accounted for over 80% of the total variance by four roots, tentatively identified as (1) Deviant Arousal; (2) for women, Deviant Socializing, for men, Self-protective Delusions; (3) for women, Self-protective Aloofness, for men, Deviant Socializing; and (4) Unusual Perceptions of Self. A noteworthy finding was that the factorial space is shared by Millon's categorical (psychiatric) variables and Eysenck's empirico-psychological constructs. Reported findings supported our assumptions about the quantitative rather than qualitative structure of human psychopathology as measured by the Millon and Eysenck scales. Both inventories complement each other by having shown dissimilar sensitivities and discriminative powers. A replication of our findings is necessary before employing the Eysenck Personality Questionnaire as a screening instrument in clinical settings.