Decided in 1971, this decision is generally held to have laid the foundation for affirmative action programs based on the rationale of under representation. The case involved black workers at a power plant in North Carolina who sued, arguing that the plant’s requirements of a high school education or passing a standardized intelligence test in order to fill certain jobs was discriminatory. The plaintiffs argued that the requirements operated to disqualify blacks at a substantially higher rate than white applicants. The plant argued that the requirements served a legitimate business purpose.

A unanimous Supreme Court disagreed with the employer, ruling that the tests did not serve any job-related requirement. The Court pointed out that the plant had practiced discrimination in the past and that the effect of these requirements was to prevent black workers from overcoming the effects of such discrimination. “Practices, procedures, or tests neutral on their face, and even neutral in terms of intent, cannot be maintained if they operate to ‘freeze’ the status quo of prior discriminatory employment practices,” said the court.

The effect of Griggs v. Duke Power was to legitimize the so-called disparate impact theory—the idea that if a qualification had a disparate impact on a specific group, an organization could justify that qualification only if it could prove a business related purpose for such a requirement. This point opened the door to forcing employers (including the government) to taking a hard look at the effect of their employment practices and their relation to race.