Arthur Jensen (born August 24 1923) is a Professor Emeritus of educational psychology at the University of California, Berkeley. Jensen is known for his work in psychometrics and differential psychology, which is concerned with how and why individuals differ behaviorally from one another. He is a major proponent of the hereditarian position in the nature versus nurture debate, the position that concludes genetics play a significant role in behavioral traits, such as intelligence and personality. He is the author of over 400 scientific papers published in refereed journals and currently sits on the editorial boards of the scientific journals Intelligence and Personality and Individual Differences.
Jensen is both among the most eminent psychologists of the twentieth century and a highly controversial figure. A special 1998 issue of the scientific journal Intelligence was entirely devoted to his life and work under the headline “A King among Men”. E. O. Wilson calls him “an honest and courageous man”. A lifelong student of Mahatma Gandhi, Jensen once offered this insight during an interview
- "One of the tenets of my own philosophy is to be as open as possible and to strive for a perfect consistency between my thoughts, both spoken and published, in their private and public expression. This is essentially a Gandhian principle, one that I have long considered worth striving to live by."
Jensen was born August 24, 1923, to a father of Danish ancestry and a mother who was half Polish Jewish and half German (non-Jewish).. Jensen studied at University of California, Berkeley (B.A. 1945), San Diego State College (M.A., 1952) and Columbia University (Ph.D., 1956). Jensen did his doctoral thesis on the Thematic Apperception Test. From 1956 through 1958, Jensen did his postdoctoral research at the University of London, Institute of Psychiatry. Upon returning to the United States, Jensen 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. Jensen received tenure at Berkeley in 1962 and was given his first sabbatical in 1964. He has concentrated much of his work on the learning difficulties of culturally disadvantaged students. In 2003, Jensen was awarded the Kistler Prize for original contributions to the understanding of the connection between the human genome and human society.
Jensen has had a life long interest in classical music and was, early in his life, attracted by the idea of becoming a conductor himself. At fourteen, Jensen conducted a band that won a nationwide contest held in San Francisco. Later, Jensen conducted orchestras and attended a seminar given by Nikolai Sokoloff. Soon after graduating from Berkeley, Jensen moved to New York, mainly to be near the conductor Arturo Toscanini. Jensen 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 black, Mexican-American, and other minority-group 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. Statistical analysis of his findings led Jensen to conclude that Level I abilities were distributed equally among members of all races, but that Level II occurred with significantly greater frequency among whites and Asian-Americans than among African-Americans and Mexican-Americans.
Later, Jensen was an important advocate in the mainstream acceptance of general intelligence factor, a concept which was essentially synonymous with his Level II conceptual learning. General intelligence 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 whites than in blacks. He suggested that from the data, one might conclude that on average, white Americans are more intelligent than African-Americans.
Jensen's most controversial work, published in February 1969 in the Harvard Educational Review, was titled "How Much Can We Boost I.Q. 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, heritability of IQ was over 0.7 of the within-race IQ variability, and the 0.3 left over was due to non-shared environmental influences.
The work became one of - if not the most - cited papers in the history of psychometrics. The release of Jensen's paper, How Much Can We Boost I.Q. and Scholastic Achievement?, sparked a huge academic controversy. Although his paper was widely cited, a random selection of 60 of these citations revealed that 29 of the papers were direct rebuttals or criticisms of Jensen's arguments, 8 cited the paper as an "example of controversy," 8 used it as a background reference. Only 15 citations of Jensen's paper were in any way supportive of his theories, 7 of these 15 were only in relation to minor points.
After the paper was released, students and faculty staged large protests outside Jensen's U.C. Berkeley office. There may have been death threats against him. Jensen was denied reprints of his work by his publisher and was not permitted to reply in response to letters of criticism -- both extremely unusual and exceptional policies for their day. Many colleagues at the time felt that even if Jensen's work contained no scientific merit, his treatment was itself against the spirit of science and the free exchange of ideas.
In a later article, Jensen argued that his claims had been misunderstood:
- ...nowhere have I "claimed" an "innate deficiency" of intelligence in blacks. My position on this question is clearly spelled out in my most recent book: "The plain fact is that at present there exists no scientifically satisfactory explanation for the differences between the IQ distributions in the black and white populations. The only genuine consensus among well-informed scientists on this topic is that the cause of the difference remains an open question" (Jensen, 1981a, p. 213).
Thomas Sowell wrote:
- Professor Jensen pointed out back in 1969 that black children's IQ scores rose by 8 to 10 points after he met with them informally in a play room and then tested them again after they were more relaxed around him. He did this because "I felt these children were really brighter than their IQ would indicate." What a shame that others seem to have less confidence in black children than Professor Jensen has had. 
However, Jensen's 1998 The g Factor: The Science of Mental Ability gives his position suggesting a genetic component is implicated in the white-black difference in IQ:
- In Chapter 12: Population Differences in g: Causal Hypotheses, Jensen writes: "The relationship of the g factor to a number of biological variables and its relationship to the size of the white-black differences on various cognitive tests (i.e., Spearman's hypothesis) suggests that the average white-black difference in g has a biological component. Human races are viewed not as discrete, or Platonic, categories, but rather as breeding populations that, as a result of natural selection, have come to differ statistically in the relative frequencies of many polymorphic genes. The genetic distances between various populations form a continuous variable that can be measured in terms of differences in gene frequencies. Racial populations differ in many genetic characteristics, some of which, such as brain size, have behavioral and psychometric correlates, particularly g."
In 1994 he was one of 52 signatories on "Mainstream Science on Intelligence," an editorial written by Linda Gottfredson and published in the Wall Street Journal, which defended the findings on race and intelligence in The Bell Curve. 
In 1995 an American Psychological Association task force published a paper titled "Intelligence: Knowns and Unknowns" which concluded that within the white population the heritability of IQ is "around .75" but also " It is sometimes suggested that the Black/ White differential in psychometric intelligence is partly due to genetic differences (Jensen, 1972).
Melvin Konner wrote in the notes to his book The Tangled Wing: Biological Constraints on the Human Spirit:
- "Statements made by Arthur Jensen, William Shockley, and other investigators in the late 1960s and early 1970s about race and IQ or social class and IQ rapidly passed into currency in policy discussions. Many of these statements were proved wrong, but they had already influenced some policymakers, and that influence is very difficult to recant."
Many studies that purport to be both science-based and attempt to influence public policy have been accused of scientific racism. Konner wrote:
- "What of the latest currents of thought? Are they likely to lead to, or at least encourage, further distortions of social policy? The indications are not all encouraging. Richard Herrnstein and Charles Murray published a book in 1994 clearly directed at policy, just as Jensen and others had in the 1960s and 1970s. The Bell Curve: Intelligence and Class Structure in American Life (New York: Free Press, 1994) teamed a psychologist with a conservative policy advocate to try to prove that both the class structure and the racial divide in the United States result from genetically determined differences in intelligence and ability."
- "Their general assertions about genes and IQ were not very controversial, but their speculations on race were something else again."
Jensen, 84, and retired, has co-authored recent articles with J. Phillipe Rushton. Konner wrote:
- "Also in the 1990s, Phillipe Rushton has tried to couch racial differences in IQ in a theory drawn from evolutionary biology. This theory takes the concepts of r and K selection, crudely useful when applied to a vast range of living creatures considered on a continuum, and apply it to subtle differences in skull form, mental test results, and sexual behavior within our one species. This theory has no academic legitimacy and little relationship to real evolutionary theory, but it taints the whole Darwinian enterprise, strongly recalling the “scientific anthropology” of the era of slavery."
- "The reality is quite different. As argued by George Armelagos in his Presidential Address to the American Association of Physical Anthropologists (“Race, Reason and Rationale,” Evolutionary Anthropology 4, 1995, pp. 103–109) race itself is a dubious concept for the human species. Obviously it is sociologically meaningful, but even in the social realm it is a constantly moving target with little or no core biological legitimacy. "
Lisa Suzuki and Joshua Aronson of New York University wrote in 2005 that Jensen has largely ignored evidence that fails to support his position that IQ test score gaps represent a genetic racial hierarchy unwaveringly for over 30 years. During this time Jensen has received more than a million dollars from the often-criticized Pioneer fund.
Gould claims that Jensen misapplies the concept of "heritability", which is defined as a measure of the variation of a trait due to inheritance within a population (Gould 1981: 127; 156-157). Jensen uses heritability to measure differences between populations.
Second, Gould disagrees with Jensen's belief that IQ tests measure a real variable, g, or "the general factor common to a large number of cognitive abilities" which can be measured along a unilinear scale. This is a claim most closely identified with Charles Spearman. According to Gould, Jensen misunderstood the research of L. L. Thurstone to ultimately support this claim; Gould however argues that Thurstone's factor analysis of intelligence revealed g to be an illusion (1981: 159; 13-314).
In a 1982 review of The Mismeasure of Man, Jensen gives point-by-point rebuttals to Gould's critique, including Gould's treatment of heritability, the "reification" of g, and the use of Thurstone's analysis. Gould's responses appear in the 1996 edition of The Mismeasure of Man.
Jensen's response and criticism
In Arthur Jensen's response to Gould's criticisms, in the paper titled The Debunking of Scientific Fossils and Straw Persons., Jensen begins his paper with this observation
- "Stephen Jay Gould is a paleontologist at Harvard's Museum of Comparative Zoology and offers a course at Harvard entitled, "Biology as a Social Weapon." Apparently the course covers much the same content as does the present book. Having had some personal cause for interest in ideologically motivated attacks on biologically oriented behavioral scientists, I first took notice of Gould when he played a prominent role in a group called Science for the People and in that group's attack on the theories of Harvard zoologist Edward O. Wilson, a leader in the development of sociobiology..."
While Jensen recognizes the validity of some of Gould's claims, in many places, he criticizes Gould's general approach
- "This charge of a social, value-laden science undoubtedly contains an element of truth. In recent years, however, we recognize this charge as the keystone of the Marxist interpretation of the history of science."
Jensen adds that Gould made a number of misrepresentations, whether intentional or unintentional, while purporting to present Jensen's own positions
- "In his references to my own work, Gould includes at least nine citations that involve more than just an expression of Gould's opinion; in these citations Gould purportedly paraphrases my views. Yet in eight of the nine cases, Gould's representation of these views is false, misleading, or grossly caricatured. Nonspecialists could have no way of knowing any of this without reading the cited sources. While an author can occasionally make an inadvertent mistake in paraphrasing another, it appears Gould's paraphrases are consistently slanted to serve his own message."
The g Factor
The g Factor: The Science of Mental Ability (1998) is considered by supporters to be Jensen's magnum opus on the general intelligence factor (g). The book deals with the intellectual history of the discovery of g and various models of how to conceptualize intelligence, and with the biological correlates of g, its heritability, and its practical predictive power.
Clocking the Mind
Jensen's book Clocking the Mind : Mental Chronometry and Individual Differences (July 17, 2006) is the culmination of 25 years of researching mental chronometry (MC), a variety of techniques for measuring the speed with which the brain processes information. Whereas IQ merely represents an ordinal (ranking) scale and thus possesses no true ratio scale properties, Jensen argues mental chronometry represents a true natural science of mental ability.
- SASP Interviews: Arthur R. Jensen. Beaujean, A. A. (2002, July). SASP News, 2 (4). (pdf)
- "A Conversation With Arthur Jensen (Part 2". (1992). American Renaissance, 3(9).
- Intelligence, Race, and Genetics: Conversations with Arthur R. Jensen. (2002) Frank Miele (of Skeptic Magazine). Westview Press. ISBN 0-8133-4008-X
Selected Articles, Books, & Book Chapters
- Rushton, J. P., & Jensen, A. R.. (2005). Thirty years of research on Black-White differences in cognitive ability. Psychology, Public Policy, & the Law, 11, 235-294. (pdf)
- Rushton, J. P., & Jensen, A. R. (2005). Wanted: More race-realism, less moralistic fallacy. Psychology, Public Policy, and Law, 11, 328-336. (pdf)
- Rushton, J. P., & Jensen, A. R. (2003). African-White IQ differences from Zimbabwe on the Wechsler Intelligence Scale for Children-Revised are mainly on the g factor. Personality and Individual Differences, 34, 177-183. (pdf)
- Jensen, A. R. (2002). Galton's legacy to research on intelligence. Journal of Biosocial Science, 34, 145-172.
- Jensen, A. R. (2002). Psychometric g: Definition and substantiation. In R. J. Sternberg, & E. L. Grigorenko (Eds.). The general factor of intelligence: How general is it? (pp. 39-53). Mahwah, NJ, US: Lawrence Erlbaum.
- Jensen, A. R. (2000). Testing: The dilemma of group differences. Psychology, Public Policy, & Law, 6, 121-128.
- Jensen, A. R. (1998) The g factor and the design of education. In R. J. Sternberg & W. M. Williams (Eds.), Intelligence, instruction, and assessment: Theory into practice. (pp. 111-131). Mahwah, NJ: Lawrence Erlbaum.
- Jensen, A. R. (1996). Giftedness and genius: Crucial differences. In C. P. Benbow, & D. J. Lubinski (Eds), Intellectual talent: Psychometric and social issues (pp. 393-411). Baltimore: Johns Hopkins University.
- Jensen, A. R. (1995). Psychological research on race differences. American Psychologist, 50, 41-42.
- Jensen, A. R. (1993). Spearman's g: Links between psychometrics and biology. In F. M. Crinella, & J. Yu (Eds.), Brain mechanisms: Papers in memory of Robert Thompson (pp. 103-129). New York: Annals of the New York Academy of Sciences.
- Jensen, A. R. (1993). Why is reaction time correlated with psychometric g? Current Directions in Psychological Science, 2, 53-56.
- Jensen, A. R. (1989). The relationship between learning and intelligence. Learning and Individual Differences, 1, 37-62.
- Kranzler, J. H., & Jensen, A. R.(1989). Inspection time and intelligence: A meta-analysis. Intelligence, 13, 329-347.
- Jensen, A. R. (1974). Ethnicity and scholastic achievement. Psychological Reports, 34, 659-668.
- Jensen, A. R. (1974). Kinship correlations reported by Sir Cyril Burt. Behavior Genetics, 4, 1-28.
- Sailer 1998
- Intelligence and Personality and Individual Differences publisher's pages.
- Jensen is listed in a study by Haggblom et al. (2002),  of the 100 most eminent psychologists of the twentieth century, at number 47.
- Cover of Intelligence, Race and Genetics (Miele 2002).
- Miele 2002
- Encyclopedia of Psychology
- While only limited inference can be drawn from citation analysis, the paper has received over 1262 citations according to the ISI citation index (Aug. 2006), compared with the other influential figures in the area, Hans J. Eysenck's 821 citations of "A Revised Version of the Psychoticism Scale" (1987; lead author Eysenck, S. B.G.), Charles Spearman's 644 of "General Intelligence Objectively Determined and Measured" (1904), James Flynn's 402 citations of "Massive IQ gains in 14 Nations - What IQ Tests Really Measure" (1987), J. Phillipe Rushton's 394 of "Behavioral-Development and Construct-Validity: the Principle of Aggregation" (1983; lead author with Brainderd C. J., Pressley M.), "Linda Gottfredson's 358 of "Circumscription and Compromise: A Developmental Theory of Occupational Aspirations" (1981), and Robert J. Sternberg's 239 of "People's Conceptions of Intelligence" (1981; lead author with Conway, BE, Ketron, JL, et al.).
- High Impact Science and the case of Arthur Jensen
- Gottfredson, Linda (December 13, 1994). Mainstream Science on Intelligence. Wall Street Journal, p A18.
- The Tangled Wing Biological Constraints on the Human Spirit Times Books Pub: 2002 ISBN: 0-7167-4602-6
- The cultural malleability of intelligence and its impact on the racial/ethnic hierarchy L Suzuki, J Aronson - Psychology, Public Policy, and Law, 2005
- The Pioneer Fund: Bankrolling the Professors of Hate Adam Miller The Journal of Blacks in Higher Education, No. 6 (Winter, 1994-1995), pp. 58-61