In the case of Detroit Edison Co. v. National Labor Relations Board, 1978, the U.S Supreme Court ruled in favor of Detroit Edison Company against a decision by the National Labor Relations Board (NLRB). The NLRB had previously ordered that individual test scores and aptitude tests should be disclosed to unions upon request as part of collective bargaining agreements. However, this was challenged by Detroit Edison on grounds that such disclosure would violate an employee's right to privacy and breach confidentiality agreements with psychological testing services used for these exams. The Supreme Court agreed with this argument stating that there is no statutory obligation under the National Labor Relations Act requiring employers to disclose such information during collective bargaining negotiations if it infringes upon employees' rights or breaches contracts with third parties.

In the dissenting opinion for Detroit Edison Co. v. National Labor Relations Board, Justice William Brennan disagreed with the majority's view that an employer is not obliged to provide a union with psychological test scores and related data used in employee transfers and promotions. He argued that this information was necessary for unions to fulfill their duty of fair representation effectively under labor laws. The denial of such information could potentially hinder unions' ability to challenge discriminatory practices or arbitrary decisions by employers, thereby undermining workers' rights protections provided by collective bargaining agreements. Furthermore, he dismissed privacy concerns raised by the majority as these tests were administered on condition of employment and employees had no reasonable expectation of privacy regarding their results.