The Bell Curve: Intelligence and Class Structure in American Life

The moral ascendancy of equality has made it difficult to use concepts such as virtue, excellence, beauty and – above all – truth.

There are better and worse ditch diggers and garbage collectors. People who work in industry know that no matter how apparently mindless a job is, the job can still be done better or worse, with significant economic consequences.

The causes of human deficiencies in intelligence—or parenting, or social behavior, or work behavior—lay outside the individual. They were caused by flaws in society.

the use of tests endured and grew because society’s largest institutions—schools, military forces, industries, governments—depend significantly on measurable individual differences.

Once again, academia and the mass media are straining every muscle to suppress debate.

Page 548: We can imagine no recommendation for using the government to manipulate fertility that does not have dangers. But this highlights the problem: The United States already has policies that inadvertently social-engineer who has babies, and it is encouraging the wrong women. If the United States did as much to encourage high-IQ women to have babies as it now does to encourage low-IQ women, it would rightly be described as engaging in aggressive manipulation of fertility. The technically precise description of America's fertility policy is that it subsidizes births among poor women, who are also disproportionately at the low end of the intelligence distribution. We urge generally that these policies, represented by the extensive network of cash and services for low-income women who have babies, be ended.

Richard Lynn was able to assemble eleven studies in his 1991 review of the literature. He estimated the median black African IQ to be 75, approximately 1.7 standard deviations below the U.S. overall population average, about 10 points lower than the current figure for American blacks.

How large is the black-white difference? The usual answer to this question is one standard deviation. In discussing IQ tests, for example, the black mean is commonly given as 85, the white mean as 100, and the standard deviation as 15.

Most Americans think that crime has gotten far too high. But in the ruminations about how the nation has reached this state and what might be done, too little attention has been given to one of the best-documented relationships in the study of crime: As a group, criminals are below average in intelligence.

Cognitive sorting continues from the time that students enter college to the time they get a degree

How good a predictor of job productivity is a cognitive test score compared to a job interview? Reference checks? College transcript? The answer, probably surprising to many, is that the test score is a better predictor of job performance than any other single measure. This is the conclusion to be drawn from a meta-analysis on the different predictors of job performance, as shown in the table below.

The logic is straightforward: A college degree supplies a credential & sometimes specific job skills that, combined with the college graduate's greater average level of intelligence should reduce the independent role of IQ in ways that would not apply as strongly to high school graduates.

because economic success in life depends in part on the talents measured by IQ tests, and because social standing depends in part on economic success, it follows that social standing is bound to be based to some extent on inherited differences.

The contrary notion—that individual differences could not easily be diminished by government intervention—collided head-on with the enthusiasm for egalitarianism, which itself collided head-on with a half-century of IQ data indicating that differences in intelligence are intractable and significantly heritable

To those who held the behaviorist view, human potential was almost perfectly malleable, shaped by the environment.

Three generations of imbeciles are enough,” Justice Oliver Wendell Holmes declared in an opinion upholding the constitutionality of such a law.

Within a few years, the letters “IQ” had entered the American vernacular, where they remain today as a universally understood synonym for intelligence.

By 1908, the concept of mental level (later called mental age) had been developed, followed in a few years by a slightly more sophisticated concept, the intelligence quotient.

The course of learning is affected by intelligence, in Spearman’s view, but it was not the thing in itself. Spearmanian intelligence was a measure of a person’s capacity for complex mental work.

in 1904, a former British Army officer named Charles Spearman made a conceptual and statistical breakthrough that has shaped both the development and much of the methodological controversy about mental tests ever since.

People differ in their talents, their intellectual strengths and weaknesses, their preferred forms of imagery, their mental vigor.

he was led to put in formal terms what most people had always taken for granted: People vary in their intellectual abilities and the differences matter, to them personally and to society.

Darwin had asserted that the transmission of inherited intelligence was a key step in human evolution, driving our simian ancestors apart from the other apes.

Gossip about who in the tribe is cleverest has probably been a topic of conversation around the fire since fires, and conversation, were invented.

Literate cultures everywhere and throughout history have had words for saying that some people are smarter than others. Given the survival value of intelligence, the concept must be still older than that.

That the word intelligence describes something real and that it varies from person to person is as universal and ancient as any understanding about the state of being human.

But there can be no real progress in solving America’s social problems when they are as misperceived as they are today. What good can come of understanding the relationship of intelligence to social structure and public policy? Little good can come without it.

In trying to think through what is happening and why and in trying to understand thereby what ought to be done, the nation’s social scientists and journalists and politicians seek explanations.

The relationships we will be discussing are among the most sensitive in contemporary America—so sensitive that hardly anyone writes or talks about them in public. It is not for lack of information, as you will see.