An Item Factor Analysis of the Eysenck Personality Inventory

Considering the wide usage of the Eysenck Personality Inventory, it was deemed desirable to critically examine the factorial nature of its Extraversion and Neuroticism scales. Of prime concern were the questions: (1) is the inventory a univocal measure of extraversion and neuroticism, for which it was designed, (2) are primary personality factors replicable ? An item factor analysis (60 variables, 1319 subjects) extracted 15 interpretable, orthogonal (Varimax) factors: Sociability I, Adjustment‐emotionality, Inferiority, Impulsivity, Mood‐swings‐readjustment, Sleep, Superego I, Jocularity, Sociability II, Dominance, Social conversation, Hypochondriac‐medical, Superego II, and two Lie factors. Obliquity of the primaries was determined by a Promax solution. It was concluded that the Extra version and Neuroticism scales are not univocal and that primary personality factors are replicable, as has been shown by a number of researchers including Eysenck. It is suggested that, until a more comprehensive and accurate inventory, to assess primary factors, is available, the EPI be scored for primary factor scales in order to present a more detailed picture of extraversion and neuroticism for the clinician and the researcher.