Hans Eysenck: Personality theorist

Hans Eysenck was the leading personality and individual differences theorist of the 20th century. His goal was to combine the best theories and practices of experimental psychology with the best measurement techniques of individual differences. From his earliest analyses of the dimensions of individual differences, through multiple iterations at theory building to his lasting achievements in building a paradigm for personality research he left a legacy of broad and rigorous research. He strove to integrate behaviour genetics, psychophysiology, cognitive psychology, aesthetics, and psychometrics into a unified theory of personality and individual differences. Although best known for his biological theory of extraversion, his impact upon the field was much more than that and cannot be summarized in a brief article. I review his major theoretical contributions and relate them to modern personality theory and show how his many contributions continue to shape current personality research.