Hans J. Eysenck

Hans J. Eysenck (1916–1997) was a German-born British psychologist and professor who taught at the University of London and held academic positions at the universities of Pennsylvania and California. He earned a PhD from University College London and became known for influential research on personality, intelligence, and psychological measurement. He also founded the journal Personality and Individual Differences and published more than 80 books and over 1,000 scientific papers.

Eysenck’s books include Test Your IQ, co-authored with Darrin Evans, as well as The Structure of Personality, Dimensions of Personality, Intelligence, and Personality and Individual Differences: A Natural Science Approach. His work helped shape modern personality assessment, including the Eysenck personality questionnaires.