Griggs v. Duke Power: Supreme Court Case, Arguments, Impact

Disparate Impact in Employment Discrimination

Student taking a test


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In Griggs v. Duke Power (1971), the Supreme Court ruled that, under Title VII of the 1964 Civil Rights Act, tests measuring intelligence could not be used in hiring and firing decisions. The court established a legal precedent for "disparate impact" lawsuits in which criteria unfairly burdens a particular group, even if it appears neutral.

Key Takeaways: Griggs v. Duke Power (1971)

  • In Griggs v. Duke Power, the Supreme Court analyzed whether using tests measuring intelligence to make hiring decisions violates the Civil Rights Act of 1964.
  • The case began when 13 black workers sued Duke Power Company after being blocked from transferring departments based on IQ tests and degree requirements.
  • The Supreme Court ruled that intelligence tests could not be used.
  • Griggs v. Duke Power Co. was the first time that the Supreme Court ruled based on "disparate impact": when a seemingly neutral policy negatively impacts a particular group.

Facts of the Case

When the Civil Rights Act of 1964 went into effect, the Duke Power Company had a practice of only allowing African American men to work in the labor department. The highest paying jobs in the labor department paid less than the lowest paying jobs in any other department at Duke Power.

In 1965, Duke Power Company imposed new rules upon employees looking to transfer between departments. Employees needed to pass two "aptitude" tests, one of which supposedly measured intelligence. They also needed to have a high school diploma. Neither of the tests measured job performance at the power plant.

Of the 14 black men working in the labor department at Duke Power's Dan River Steam Station, 13 of them signed onto a lawsuit against the company. The men alleged that the company's actions violated Title VII of the Civil Rights Act of 1964.

Under Title VII of the Civil Rights Act of 1964, an employer involved in interstate commerce cannot:

  1. Take negative employment action (failing to hire, choosing to fire, or discriminating) against an individual because of the individual's race, color, religion, sex, or national origin;
  2. Limit, segregate or classify employees in a way that negatively impacts their employment opportunities because of their race, color, religion, sex, or national origin.

Constitutional Issue

Under Title VII of the Civil Rights Act, can an employer require an employee to graduate high school, or pass standardized tests that are unrelated to job performance?

The Arguments

Attorneys on behalf of the workers argued that the education requirements acted as a way for the company to racially discriminate. The segregation in schools in North Carolina meant that black students received an inferior education. Standardized tests and degree requirements prevented them from becoming eligible for promotions or transfers. Under Title VII of the Civil Rights Act, the company could not use these tests to guide departmental transfers.

Attorneys on behalf of the company argued that the tests were not meant to discriminate on the basis of race. Instead, the company intended to use the tests to increase the overall quality of the workplace. Duke Power did not specifically prevent black employees from moving between departments. If the employees could pass the tests, they could transfer. The company also argued that the tests could be used under section 703h of the Civil Rights Act, which allows "any professionally developed ability test" that is not "designed, intended or used to discriminate because of race[.]"

Majority Opinion

Chief Justice Berger delivered the unanimous decision. The Court found that the tests and degree requirement created arbitrary and needless barriers that indirectly impacted black workers. The tests could not be shown to be at all related to job performance. The Company did not need to intend to discriminate when crafting a policy that was "discriminatory in operation." The majority opinion found that what mattered was that the disparate impact of the policy was discrimination.

In terms of the importance of degrees or standardized tests, Chief Justice Berger noted:

"History is filled with examples of men and women who rendered highly effective performance without the conventional badges of accomplishment in terms of certificates, diplomas, or degrees."

The Court addressed Duke Power's argument that section 703h of the Civil Rights Act allowed for ability tests in the majority opinion. According to the Court, while the section did allow for tests, the Equal Employment Opportunity Commission had clarified that the tests must be directly related to job performance. Duke Power's aptitude tests had nothing to do with the technical aspects of jobs in any of the departments. As a result, the company could not claim that the Civil Rights Act allowed the use of their tests.


Griggs v. Duke Power pioneered disparate impact as a legal claim under Title VII of the Civil Rights Act of 1964. The case was originally applauded as a win for civil rights activists. However, over time federal courts have increasingly narrowed its usage, creating restrictions for when and how an individual can bring a disparate impact lawsuit. In Ward’s Cove Packing Co., Inc. v. Antonio (1989), for example, the Supreme Court gave plaintiffs the burden of proof in a disparate impact lawsuit, requiring that they show specific business practices and their impact. Plaintiffs would also need to show that the company refused to adopt different, non-discriminatory practices.


  • Griggs v. Duke Power Co., 401 U.S. 424 (1971).
  • Wards Cove Packing Co. v. Atonio, 490 U.S. 642 (1989).
  • Vinik, D. Frank. “Disparate Impact.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 27 Jan. 2017,