Purpose

The main purpose of the Eysenck Personality Questionnaire for Adults (EPQ-A) is to assess the core dimensions of personality in adults, based on Hans Eysenck’s Five-Factor Theory. The instrument is designed to quantitatively capture three principal dimensions of personality: Extraversion, Neuroticism, and Psychoticism, along with an additional scale that evaluates response validity through the Lie scale. These dimensions aim to reflect traits related to sociability, emotional stability, aggression, antisocial tendencies, and the tendency to provide socially desirable answers rather than truthful ones.

Description

The original English version of the EPQ-A comprises 90 items. The Greek adaptation, developed by E. Dimitriou in the 1970s and 1980s, consists of 84 questions. These items are divided across four main scales, each designed to examine a specific dimension of personality. Specifically, the Extraversion scale includes 19 questions assessing social engagement, energy, and outward-oriented behavior. The Psychoticism scale contains 24 items and evaluates traits such as coldness, hostility, antisocial behavior, and aggressiveness. The Neuroticism scale consists of 22 items measuring emotional instability, anxiety, and difficulty managing stress. Finally, the Lie scale includes 19 questions and aims to detect the tendency of the respondent to answer in a socially desirable manner rather than truthfully.

Sample

The Greek version of the EPQ-A was administered to a total sample of 802 adults, comprising 252 men and 550 women, from various regions across Greece. Participants ranged in age from 18 to 79 years, with a mean age of 29 years. The demographic variety of the sample allows for valid and reliable conclusions to be drawn regarding adult personality traits across different social and demographic contexts.

Scoring

The EPQ-A consists of dichotomous “Yes/No” questions. Scoring is straightforward and depends on the direction of each item. For positively worded items (where a “No” indicates presence of the trait), a “No” response scores 1 point, while a “Yes” scores 0. Conversely, in reverse-scored items (where a “Yes” implies the trait), a “Yes” scores 1 and a “No” scores 0. The total score for each scale provides a quantitative measure of the presence and intensity of the corresponding personality trait.

Validity

The validity of the EPQ-A has been examined through its correlation with other established psychometric instruments, such as the Trait Personality Questionnaire (TPQue). Statistical analysis demonstrated a significant correlation between the two instruments in relation to the Extraversion scale, supporting the construct validity of this dimension. However, the correlation with the Neuroticism scale was not statistically significant, indicating potential limitations in the construct validity of this dimension or suggesting a need for further cultural adaptation of the instrument in the Greek context.

Reliability

The reliability indices of the EPQ-A were found to be particularly satisfactory for most scales. Internal consistency coefficients (Cronbach’s alpha) ranged from 0.77 to 0.83 for the overall sample, as well as for male and female subgroups, indicating high homogeneity within each scale. The only exception was the Psychoticism scale, which showed lower reliability coefficients ranging from 0.46 to 0.61. This may be attributed to cultural differences in interpreting specific items or to the conceptual variability of psychoticism traits within the general population.

References

Alexopoulos, D. S. (2002). Reliability and validity of the Eysenck Personality Questionnaire for Adults (EPQ-A) in Greece. Psychology, 9(3), 295–315.
Dimitriou, E. (1986). The Eysenck Personality Questionnaire (EPQ): Standardization in the Greek adult and child population. Encephalos, 23, 41–54.
Eysenck, H. J., & Eysenck, S. B. G. (1991). Eysenck Personality Questionnaire – Revised (EPQ-R). London: Hodder & Stoughton.