Background
History of IQ and SAT
The Nature vs. Nurture Debate

History of IQ and SAT

Prior to the early twentieth century, the predominant theories of the nature of intelligence emphasized the importance of brain size and heredity. Alfred Binet (1857-1911) began his study of intelligence as the director of the psychology laboratory at Sorbone in France. He attempted to study intelligence by comparing the cranium size of the test subjects, the accepted method at this time. However, Binet discovered peculiar evidence that contradicted the orthodox theories of intelligence. Binet found that the difference in cranium size between good and poor students was very small. More unexpectedly, he discovered that the size of the poor students' crania exceeded that of their "smarter" counterparts by 3 mm (Gould, 1981). These findings rocked the standard method of measuring intelligence. How was intelligence to be measured once "craniometry" lost its validity?

Binet returned to his study of intelligence in 1904 when the minister of public education in France commissioned him to identify those students who needed to attend "special" schools due to their inability to succeed in normal schools. Binet tested students on their performance of everyday tasks, such as counting coins (Lawler, 1978). Binet assigned an age level to each task - the "mental age." The subject would complete tasks in ascending order of mental age. The mental age of the last task that the subject could complete was determined to be the mental age of that individual. The subject's general intelligence level was calculated by subtracting his mental age from his true chronological age. Children whose mental age was significantly behind their chronological age were assigned to special education.

In 1912 W. Stern suggested the division of mental age by chronological age in order to determine intelligence. The intelligence quotient, or IQ, was born. It is important to note that Binet attempted to measure aptitude, not acquired knowledge. Whether or not aptitude can be accurately measured free of environmental variables is a separate issue that will be discussed in other sections of this web site. It is also essential to realize that Binet did not intend for this test to be applied to all sectors of society as a device for the measurement of intelligence. Binet created this test for the sole purpose of determining those students in need of specialized schooling. He felt intelligence was too complex to be measured by a specific test. Furthermore, he viewed IQ as only a "rough empirical guide" (Gould, 1981).

Alfred Binet's test was brought to America by three influential psychologists -L.M. Terman of Stanford, H.H. Goddard of the Vineland Training School in New Jersey, and R.M Yerkes of Harvard. All three of these men were influential pioneers of the testing industry. They felt IQ could be used to determine the innate intelligence of all members of society (Kamin, 1974). Also, they believed that intelligence was a hereditary trait that could be accurately measured. Although Goddard and Yerkes made tremendous contributions to the field of intelligence testing, Terman was undeniably the most influential of the three.

Terman developed the "Stanford-Binet" test in 1916. The goal of the test was to "curtail the reproduction of feeble-mindedness" (Kamin, 1974). Terman wanted to identify those members of society who were unintelligent and limit their reproduction. He saw "feeble mindedness" as a moral, social, and economic threat to American society. Consequently, he felt that it was absolutely necessary to identify the intelligence of all individuals in order to discover who was corrupting the nation.

Terman saw immigration as a tremendous threat to the welfare of the nation and was a strong proponent of the use of IQ standards to selectively control it. He did not want to allow any individual to set foot on American soil unless he or she could be a benefit to the society, both economically and socially. Terman refined Binet's original test by establishing more specific statistical guidelines to each mental age. He also developed a more scientific manner in which to administer the test. Ultimately, the Stanford-Binet test became the primary intelligence test in the world and is still widely used today.

The Scholastic Aptitude Test (SAT) was developed in 1923 by T.L. Kelley, G.M. Ruch, and Terman. It was designed to predict the success of students in school. Its creators claimed that it accurately measured one's ability to learn. The SAT later became very controversial because some asserted that it measured academic achievement, not aptitude. Many of these critics argued that it was culturally biased, suggesting that it tested a child's knowledge of "white" culture.

The SAT was later renamed the Standardized Achievement Test because of the acceptance that achievement was the major variable being tested. Recently, the content of many questions has been changed. For example, the test no longer consists of solely upper-middle class content; rather some questions now contain content from minority cultures as well. Although progress has been made in reducing bias in the SAT, the majority of the questions still provide a tremendous advantage to those who are familiar with mainstream white culture.

Clearly, the SAT and IQ tests have tremendous influence in contemporary American society. IQ test scores are used to place students in specialized tracks in school and serve as a general label of one's intelligence. SAT scores are tremendously important in college admissions and, to some extent, in the job market. Whether or not these tests are valid indicators of the variables they aim to measure is a subject of much debate - a subject that will be tackled in the ISSUES AND OPTIONS section of this web site.

The Nature vs. Nurture Debate

It is an indisputable fact that African-Americans tend to perform more poorly than whites on standardized tests. The cause of this phenomenon is highly debated. This section briefly outlines the debate about the question of whether genetics (nature) or environment (nurture) is the primary explanation for the racial disparities in test scores.

In 1969 Arthur Jensen argued that genetics is the reason why the average white score is 15 points higher than the average black score on IQ tests. His research consisted of comparing IQ. scores of twins that were separated at birth. He found that the average difference in IQ. for the twins was "less than the difference of two unrelated individuals raised in similarly varied environments" (Gould, 1975, p. 147).

From the data Jensen compiled, he estimated the magnitude of environmental and genetic influence. He concluded that IQ. has a heritability of 0.8 (80%), leaving only 0.2 or 20% of the influence to a person's environment. He argued that limits exist to what education can do for people and that an individual's education should reflect what they are biologically suitable for. Furthermore, in Bias and Mental Testing (1980) Jensen once again argued that genetics are far more important to IQ. scores than environment. He also asserted that the tests are valid because they accurately predict student performance.

Reactions to Jensen's work are abundant. Stephen Jay Gould of Harvard University explains, "the expression of any trait represents complex interactions of heredity and environment"(Gould, 1975, p. 149). Gould offered the example of height. A person is likely to be tall if their parents and grandparents are, but if the person lacks proper nutrition then it may not reach its genetic potential for height. Richard C. Lewontin asserted that Jensen made a fundamental error: "to confuse hereditability of a character within a population with hereditability of the difference between two populations"(Lewontin, 1975, p. 189). Also, genetics specialist Jerry Hirsch disagrees with Jensen's results. He explains, "one cannot infer from a high hereditability value that the influence of environment is small or unimportant"(Hirsch, 1968, p. 42). J. Philippe Rushton is perhaps the most controversial psychologist of his time. He attributed low test scores to the genetically inherited trait of brain size. Rushton explained that East Asians have both the largest brain size and the highest scores on standardized tests. He claimed that black people have the smallest brain size (corresponding with their relatively poor performance on standardized tests) and that whites are in the middle of both categories.

Rushton's research was challenged by Marvin Zuckerman, who claimed that there is much more variation within groups than between groups. Also, Zuckerman included the data from a cross-cultural study by Paul Barrett and Sybil Eysenck (1984) that suggested genetics is far less relevant than Rushton claimed. Furthermore, others discount Rushton's claims with the assertion that his experimental data came from Nazi concentration camps.

Sandra Scarr sought to end the debate by separating genetic factors from child-rearing conditions. Scarr tried to remove class difference in her experiment because African-Americans are disproportionately in the lower socioeconomic classes. Therefore, many suggest that what may appear to be a genetic difference in the tests is actually due to the influence of one's socioeconomic class. Scarr studied 130 black/interracial children adopted by advantaged white families. She found that the black subjects did score above both the IQ. mean and school achievement average of the white population, but they did not, however, "perform as well as either the adoptive parents or their biological children" (Scarr, 1976, p. 731). Scarr estimated that heritability of IQ. lies between .40 and .70 and that IQ. scores are highly malleable because of environmental factors that affect a child's development.

Leon J. Kamin of Princeton University commented on Scarr's research in her book Race, Social class, and Individual Difference in IQ. (1981). Kamin stated that selective reporting was inevitable because of the massive quantity of data that she accumulated (Kamin, 1981, p. 469). He also noted that while the black children in her sample gained the benefits of being raised in upper class, white homes, there still remained the possibility of racism because their skin color had not changed.

More troubling to Kamin was the way in which Scarr attempted to match control families with test families. He explained that the "nexus of intercorrelated environmental indices may differ systematically between adoptive and demographically matched families" (Kamin, 1981, p. 469). After analyzing Scarr's data, Kamin claimed that IQ. heritability is much closer to zero than .40 to .70.

The Bell Curve, written by Richard J. Herrnstein and Charles Murray, has been called the most controversial book of the 1990's. Herrstein and Murray stress three main points: 1) All races are represented across the range of intelligence from lowest to highest, 2) American blacks continue to score lower on standardized tests than whites, 3) SAT and IQ. tests are good predictors of academic and job performance. The Bell Curve claimed that although environment does influence test scores, genetic factors are far more significant.

The conclusions of Herrnstein and Murray sparked considerable debate. The reaction was so sharp that the American Psychological Association (APA) was compelled to write its own report on The Bell Curve. The report, written by Neisser et al., concluded, "there is no empirical support for a genetic interpretation" (American Psychologist, January, 1997, p. 69). However, the position of the APA was criticized by numerous psychologists, including Rushton and Lynn, for omitting some of the evidence presented in The Bell Curve.

It now appears that this debate may never be resolved. No argument has yet been persuasive enough to create a consensus. Regardless of the causes of the discrepancies, many suggest the creation of policies to alleviate their consequences.
Government 375: Educational Reform and Ideology