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.
Early life and education
Jensen was born August 24, 1923, in San Diego, California, the son of Linda Mary (née Schachtmayer) and Arthur Alfred Jensen, who operated and owned a lumber and building materials company. His paternal grandparents were Danish immigrants and his mother was of half-Polish Jewish and half-German descent.
As a child, Jensen was interested in herpetology and classical music, playing clarinet in the San Diego Symphony orchestra.
Jensen received a B.A. in psychology from the University of California, Berkeley in 1945 and went on to obtain his M.A. in psychology in 1952 from San Diego State College. He earned his Ph.D. in clinical psychology from Columbia University in 1956 under the supervision of Percival Symonds on the thematic apperception test. From 1956 through 1958, he did postdoctoral research at the University of London, Institute of Psychiatry with Hans Eysenck.
Upon returning to the United States, he became a researcher and professor at the University of California, Berkeley, where he focused on individual differences in learning, especially the influences of culture, development, and genetics on intelligence and learning. He received tenure at Berkeley in 1962. He concentrated on the learning difficulties of culturally disadvantaged students.
Jensen had a lifelong interest in classical music and was, early in his life, attracted by the idea of becoming a conductor himself. At 14, he conducted a band that won a nationwide contest held in San Francisco. Later, he conducted orchestras and attended a seminar given by Nikolai Sokoloff. Soon after graduating from Berkeley, he moved to New York, mainly to be near the conductor Arturo Toscanini. He was also deeply interested in the life and example of Gandhi, producing an unpublished book-length manuscript on his life. During Jensen's period in San Diego he spent time working as a social worker with the San Diego Department of Public Welfare.
IQ and academic achievement
Jensen's interest in learning differences directed him to the extensive testing of school children. The results led him to distinguish between two separate types of learning ability. Level I, or associative learning, may be defined as retention of input and rote memorization of simple facts and skills. Level II, or conceptual learning, is roughly equivalent to the ability to manipulate and transform inputs, that is, the ability to solve problems.
Later, Jensen was an important advocate in the mainstream acceptance of the general factor of intelligence, a concept which was essentially synonymous with his Level II conceptual learning. The general factor, or g, is an abstraction that stems from the observation that scores on all forms of cognitive tests correlate positively with one another.
Jensen claimed, on the basis of his research, that general cognitive ability is essentially an inherited trait, determined predominantly by genetic factors rather than by environmental conditions. He also contended that while associative learning, or memorizing ability, is equally distributed among the races, conceptual learning, or synthesizing ability, occurs with significantly greater frequency in some races than in others.
Jensen's most controversial work, published in February 1969 in the Harvard Educational Review, was titled "How Much Can We Boost IQ and Scholastic Achievement?" It concluded, among other things, that Head Start programs designed to boost African-American IQ scores had failed, and that this was likely never to be remedied, largely because, in Jensen's estimation, 80% of the variance in IQ in the population studied was the result of genetic factors and the remainder was due to environmental influences.