Dimensions of Personality was published by Kegan Paul in 1947, and it established the research program that would occupy Eysenck for the rest of his career: the attempt to describe human personality using a small number of statistically derived dimensions rather than the proliferating categories of clinical psychology. Using factor analysis on data collected from seven hundred neurotic soldiers during World War II, Eysenck identified two orthogonal dimensions: neuroticism (emotional stability versus instability) and extraversion-introversion.
The approach was revolutionary in its insistence on measurement. Where previous personality theorists (Freud, Jung, Adler) had relied on clinical observation and theoretical speculation, Eysenck insisted that personality must be studied with the same quantitative rigor applied to physical phenomena. Factor analysis — a statistical technique for identifying underlying patterns in large datasets — provided the tool: by analyzing how personality traits cluster together in real populations, Eysenck could identify the fundamental dimensions without relying on theory.
The two-dimensional model was deliberately parsimonious. Eysenck argued that the proliferation of personality types in clinical psychology (the hundreds of diagnoses, the dozens of character types) reflected conceptual confusion rather than genuine complexity. A small number of fundamental dimensions, rigorously derived, could account for the observed variation in human personality more accurately than any number of clinically derived categories.
Collecting Dimensions of Personality
First edition (Kegan Paul, London, 1947): Cloth binding, dust jacket.
Market values:
- First edition in dust jacket: $80–$200
- Without jacket: $20–$50