Arthur Jensen - IQ and Academic Achievement

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. Jensen concluded 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 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 Asians than in whites. He suggested that from the data one might conclude that, on average, Asian Americans are more intelligent than white Americans.

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.

The work became one of—if not the most—cited papers in the history of psychological testing and intelligence research. It 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, and 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. 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 policies for their day.

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 declared the consensus of the signing scholars on the meaning and significance of IQ following the publication of the book The Bell Curve.

In 2005, Jensen's article, co-written with J. Philippe Rushton, named "Thirty Years of Research on Race Differences in Cognitive Ability", was published in the APA journal Psychology, Public Policy and Law. Jensen and Rushton present ten categories of evidence in support of the notion that IQ differences between whites and blacks are partly genetic in origin.