Under U.S. constitutional law, a “heightened rational basis” test is used in the context of gender discrimination: the classification must serve “important” governmental objectives, and the discriminatory means employed must be “substantially related” to the achievement of these ends.

Under U.S. constitutional law, a “heightened rational basis” test is used in the context of gender discrimination: the classification must serve “important” governmental objectives, and the discriminatory means employed must be “substantially related” to the achievement of these ends. Mississippi University for Women v. Hogan, 458 U.S. 718 (1982); see also United States v. Virginia, 116 S.Ct. 2264 (1996) (gender discrimination unconstitutional in absence of “exceedingly persuasive justification”).

Under U.S. federal statutory law, Title VII of the Civil Rights Act of 1964 prohibits discrimination on the basis of sex by employers. The Pregnancy Discrimination Act of 1978 extended the definition of sex to include pregnancy. International Union, UAW v. Johnson Controls, 499 U.S. 187 (1991). Refusal to hire on these grounds as well as harassment and hostile working environments are included within the scope of the statute. Meritor Savings Bank v. Vinson, 477 U.S. 57 (1986) (holding that sexual harassment in violation of Title VII exists in a workplace that creates a “hostile environment”). In addition, sex-based wage discrimination claims can also be brought under Title VII. County of Washington v. Gunther, 452 U.S. 161 (1981).

The main exception to the prohibition on purposeful discrimination is the bona fide occupational qualification (BFOQ), which provides that employers may refuse to hire on the basis of race, color, religion, sex, or national origin if members of the excluded class cannot perform the essential job duties. See, e.g., Dothard v. Rawlinson, 433 U.S. 321 (1977) (upholding Alabama prison practice of not hiring women guards because of unusually dangerous prison conditions). However, the federal courts have drawn this exception quite narrowly, refusing to accept stereotypes and customer preferences as justifications. See, e.g., Diaz v. Pan Am. World Airways, Inc., 442 F.2d 385 (5th Cir. 1971) (rejecting customer preference for female flight attendants as BFOQ); Weeks v. Southern Bell Tel. & Tel. Co., 408 F.2d 228 (5th Cir. 1969) (rejecting concern for welfare of women performing dangerous jobs as BFOQ).