Eysenck Personality Questionnaire

Abstract

The Eysenck Personality Questionnaire (EPQ) is a highly influential self-report instrument used in personality psychology. It represents a further refinement and development of the earlier Eysenck Personality Inventory (EPI), designed to measure the most important basic dimensions of personality, often referred to as the Giant Three. The original EPQ consisted of 90 items, but the widely utilized revised version, the EPQ-R, expanded the instrument to 101 items, subdivided into four distinct domains. Its availability in various countries facilitates extensive cross-cultural research studies. This entry specifically describes the properties and structure of the revised version, the EPQ-R.

Keywords

Eysenck Personality Questionnaire, EPQ-R, Eysenck’s Three-Factor Model, Personality Assessment, Psychoticism, Extraversion, Neuroticism, Lie Scale, Psychometrics

Authors

EPQ: Eysenck HJ, Eysenck SBG (1975); EPQ-R: Eysenck HJ, et al. (1985); Dutch version: Sanderman R, et al. (1991)

Purpose

The primary purpose of the EPQ is to provide a standardized, reliable, and valid measure of the three fundamental dimensions of personality as conceptualized by Hans and Sybil Eysenck: Psychoticism (P), Extraversion (E), and Neuroticism (N). These dimensions are viewed as biologically based traits that underpin human behavior and temperament.

The scale is utilized extensively in clinical, occupational, and academic settings for descriptive assessment, research into the genetic and biological basis of personality, and for exploring relationships between personality traits and various behavioral or psychological outcomes, including vulnerability to mental health issues.

Construct

The EPQ-R measures the three core dimensions (P, E, N) plus a Lie Scale (L) designed to detect response distortion or social desirability bias. These dimensions constitute the hierarchical model of personality proposed by Eysenck:

• Psychoticism (P): Reflects a tendency towards hostility, impulsivity, non-conformity, aggression, and a lack of empathy. High scores may be associated with risk-taking and antisocial tendencies.
• Extraversion (E): Measures sociability, activity, assertiveness, and excitability. Individuals scoring high on Extraversion are typically outgoing and enjoy social interaction.
• Neuroticism (N): Measures emotional instability, anxiety, worry, and general emotional reactivity. High scores suggest a tendency toward moodiness and distress.
• Lie Scale (L): An independent scale included to assess the extent to which the respondent is faking good or attempting to present an unrealistically positive self-image.

Validity

The validity of the EPQ-R has been extensively studied across diverse cultural and linguistic groups, providing strong evidence for its construct validity. The instrument demonstrates expected correlations with other established measures of personality, such as the Revised NEO Personality Inventory (NEO PI-R), supporting its convergent validity, particularly concerning the Extraversion and Neuroticism scales, which overlap conceptually with the Big Five factors.

Furthermore, the scale exhibits predictive validity in various domains, including academic performance, susceptibility to certain psychological disorders (e.g., high Neuroticism is linked to anxiety and depression), and occupational suitability. Cross-cultural studies confirm that the factor structure generally holds across different populations, supporting the universality of Eysenck’s dimensions.

Reliability

Reliability studies consistently demonstrate that the EPQ-R possesses high internal consistency for its primary scales, particularly Extraversion and Neuroticism, often yielding Cronbach’s alpha coefficients well above 0.70. The Psychoticism scale, due to the heterogeneity of the traits it encompasses, sometimes shows slightly lower, though acceptable, internal consistency in certain populations.

The instrument also exhibits robust test-retest reliability over short and long intervals, indicating that the measured personality traits are stable over time, consistent with Eysenck’s theory that these dimensions are enduring, biologically determined characteristics.

Factor Analysis

The structure of the EPQ-R is fundamentally derived from factor analysis. Initial exploratory factor analysis (EFA) confirmed the orthogonality and independence of the three major factors (P, E, N). Subsequent Confirmatory Factor Analysis (CFA) across numerous international samples has largely supported the hypothesized four-factor structure (P, E, N, L), confirming that the items load reliably onto their intended dimensions.

While minor variations in factor loadings may occur across different cultural adaptations, the consistent empirical demonstration of the three orthogonal factors—Psychoticism, Extraversion, and Neuroticism—has cemented the EPQ-R’s position as a key tool for measuring Eysenck’s dimensional model of personality.

Instrument

Test Type: Questionnaire (Self-Report Instrument)

Format: The EPQ-R typically uses a dichotomous (Yes/No) response format, making it quick and straightforward for respondents to complete. The revised version contains 101 items.

Language Available: English, Dutch, and numerous other translations, facilitating cross-cultural research.

Population Group: Adults

Age Group: Typically administered to individuals aged 16 and older.

Population Details: Suitable for general population samples, clinical samples, and various occupational groups.

Test Methodology: The instrument uses established psychometric methods to quantify core personality dimensions based on the respondent’s self-assessment of typical behaviors, feelings, and reactions.

Keywords

Eysenck, EPQ, EPI, Neuroticism, Extraversion, Psychoticism, Factor Analysis, Clinical Psychology, Trait Theory

Authors

Author ORCID Identifier: Not specified in source material.

Affiliation Email addresses: Not specified in source material.

Correspondence Address: Not specified in source material.

Permissions & Fee and Test Year

The original Eysenck Personality Questionnaire (EPQ) was published in 1975. The revised and most commonly used version, the EPQ-R, was published in 1985. The Dutch adaptation described in the source material was published in 1991 by Sanderman R, et al. Permissions and fees for the use of the EPQ-R are typically managed by the respective regional psychological test publishers.

Reference’s

Eysenck, H. J., & Eysenck, S. B. G. (1975). Manual of the Eysenck Personality Questionnaire (Junior and Adult). Hodder and Stoughton.

Eysenck, H. J., Eysenck, S. B. G., & Barrett, P. (1985). A revised version of the Psychoticism scale. Personality and Individual Differences, 6(1), 21-29.

Sanderman R, et al. (1991). Handleiding bij de Nederlandse bewerking van de Eysenck Personality Questionnaire (EPQ). Swets & Zeitlinger.

The original PDF documentation for the Explanation Form can be downloaded here: Toelichtingsformulier PDF

The original PDF documentation for the Measurement Instrument can be downloaded here: Meetinstrument PDF

The original PDF documentation for the Manual can be downloaded here: Handleiding PDF

Items of the Eysenck Personality Questionnaire

IMPORTANT: The following scale items must be preserved in their original language and must not be changed in any way.

The specific items of the questionnaire were not provided in the source text. However, the instrument is a 101-item questionnaire (EPQ-R) designed to measure the four primary dimensions: Psychoticism, Extraversion, Neuroticism, and the Lie Scale.