Arthur Robert Jensen (August 24, 1923 – October 22, 2012) was an American psychologist and writer. He was a professor of educational psychology at the University of California, Berkeley. Jensen was known for his work in psychometrics and differential psychology, the study of how and why individuals differ behaviorally from one another. He was a major proponent of the hereditarian position in the nature and nurture debate, the position that genetics play a significant role in behavioral traits, such as intelligence and personality. He was the author of over 400 scientific papers published in refereed journals and sat on the editorial boards of the scientific journals Intelligence and Personality and Individual Differences. Jensen was controversial, largely for his conclusions regarding the causes of race-based differences in IQ. Source: Wikipedia (en)