A psychometric investigation of the Eysenck Personality Questionnaire

Abstract

Summaries of item properties for the Eysenck Personality Questionnaire (EPQ) are reported, based upon the responses of 99 male and 92 female undergraduate psychology students. Means, standard deviations, and internal consistencies were comparable to those already published, with the exception of lower reliabilities for the P and L scales. A high incidence of extreme p values and correlation with social desirability was noted for the P scale. Item factor analyses at both the first- and third-order levels did not replicate the four-factor structure claimed by Eysenck; at best, four components accounted for approximately 30% of the observed variance. Many items did not load in accordance with the EPQ scoring key, and many items did not load on an interpretable component. The question of difficulty factors is discussed: None were located. It is concluded that there is little empirical support for the structure claimed for the EPQ.