A large body of research indicates that IQ ("intelligence quotient") and similar measures vary between individuals and between certain groups, and that they correlate with socially important outcomes such as educational achievement, employment, crime, poverty and socioeconomic status.
In the United States, certain public policies and laws regarding employment, military service, education and crime incorporate IQ or similar measurements.
Eugenics fell out of favor in the middle part of the century and is now widely denounced, though memories of the period continue to influence public policy.
[3][4] The 9th Circuit Court of Appeals interpreted state and federal statutes to require that IQ tests not be used in a manner that was determinative of tracking students into classes designed for the mentally retarded.
The court specifically found that the tests involved were designed and standardized based on an all-white population, and had not undergone a legislatively mandated validation process.
A major area of controversy regarding the NCLB Act is whether achievement gaps are the result of "the soft bigotry of low expectations"[1] or reflect real cognitive ability differences between groups.
[7]Before the late twentieth century, on the basis of studies showing widely varying validities for personnel selection techniques, the theory of "situational specificity" held sway.
In 1971, in the case Griggs v. Duke Power Co.[1],[10] the US Supreme Court handed down a seminal ruling which framed US public policy on adverse impact.
Griggs concerned a company which had rejected a large number of Black applicants who either lacked a high-school education or performed poorly on a paper-and-pencil cognitive test.
In Griggs, the Court ruled that the reliance solely on a general IQ test that was not found to be specifically relevant to the job at issue was a discriminatory practice where it had a "disparate impact" on hiring.
The U.S. military uses the Armed Forces Qualifying Test (AFQT), as higher scores correlate with significant increases in effectiveness of both individual soldiers and units.
[16] In its 2002 ruling on the case Atkins v. Virginia, the US Supreme Court outlawed the execution of intellectually-disabled criminals on the grounds that it constituted cruel and unusual punishment, which is prohibited by the 8th Amendment.
The Supreme Court case of Atkins v. Virginia, decided June 20, 2002,[17] held that executions of mentally challenged criminals are "cruel and unusual punishments" prohibited by the Eighth Amendment.
In overturning the Virginia Supreme Court's holding, the Atkins opinion stated that petitioner's IQ result of 59 was a factor making the imposition of capital punishment a violation of his eighth amendment rights.
In the opinion's notes the court provided some of the facts relied upon when reaching their decisionAt the sentencing phase, Dr. Nelson testified: "Atkins' full scale IQ is 59.
[20] Later observations of phenomena such as the Flynn effect, and the steady closing of the gap between black and white Americans, along with recognition of disparities in access to prenatal care, all highlighted ways in which environmental factors affect group IQ differences.
[23][24] In recent decades, as understanding of human genetics has advanced, claims of inherent differences in intelligence between races have been broadly rejected by scientists on both theoretical and empirical grounds.