Eysenck Personality Inventory (EPI): Traits, Scoring & Applications

Overview

The Eysenck Personality Inventory (EPI) is a self-report questionnaire measuring three major personality dimensions: Extraversion (E), Neuroticism (N), and Psychoticism (P). Developed by Hans and Sybil Eysenck (1950s–60s); widely used in research, occupational, and clinical settings globally.

Structure

57 yes/no items (original EPI); later versions (EPQ-R) have 100 items with 4-point scales. Takes 10–15 minutes.

Three Scales

• Extraversion (E): Sociable, outgoing, active, sensation-seeking, assertive vs. introverted, reserved, quiet, reflective. High E = cortical under-arousal → seeks stimulation.
• Neuroticism (N): Emotionally reactive, anxious, worried, moody, vulnerable to stress vs. emotionally stable, resilient, calm. High N = limbic system hyper-reactivity.
• Psychoticism (P): Aggressive, impulsive, antisocial, egocentric, creative, tough-minded vs. controlled, conventional, prosocial, empathetic. High P = associated with risk for psychosis, antisocial behavior (but not diagnostic).

Also includes a Lie Scale (L) measuring social desirability response bias.

Applications

• Research: Personality correlates of behavior, health, creativity, psychopathology.
• Occupational: Employee selection for roles requiring specific traits (sales→high E; air traffic control→low N).
• Clinical: Trait profiling; high N+P associated with various disorders.

Limitations

Reliable and valid for trait measurement, but not a diagnostic tool. Should not replace professional mental health evaluation. Cultural bias in norms; P scale controversial. Modern Five-Factor Model (Big Five) more widely used in research.