Eysenck Personality Questionnaire (EPQ)

The Eysenck Personality Questionnaire (EPQ)

The EPQ is a self-report inventory developed by Hans Eysenck to measure the major dimensions of personality. It grew out of Eysenck's earlier work, which had identified two core dimensions that he believed captured the most important differences between people.

The original two dimensions

Eysenck's initial model assessed personality along two independent axes:

• Introversion – Extraversion: This dimension describes where a person directs their energy. An extravert is outgoing, sociable, and seeks stimulation, while an introvert is more reserved, reflective, and prefers quieter environments.
• Emotional Stability – Emotional Instability (Neuroticism): This dimension measures a person's tendency to experience negative emotions. A stable person is calm and even-tempered, while an emotionally unstable person is prone to anxiety, moodiness, and worry.

Each of these two dimensions is characterised by a set of 32 specific personality traits. These traits are the building blocks that define the broader dimension. For example, traits like sociability, liveliness, and assertiveness would cluster together to define extraversion, while traits like anxiety, guilt, and low self-esteem would cluster to define emotional instability.

The addition of a third dimension

Later, Eysenck added a third dimension to the questionnaire: Psychoticism.

This dimension is linked to psychopathology — that is, to patterns of thinking and behaving that are associated with mental illness. A person who scores high on psychoticism tends to show:

• A lack of feeling for others (low empathy)
• A tough, insensitive manner of interacting with people
• A tendency to defy social conventions and norms …