Federal employment law, in the Age Discrimination in Employment Act (the “ADEA”),prohibits employers from firing, refusing to hire, or discriminating in compensation, terms, conditions, or privileges of employment because of a person’s age. Case law has evolved over time regarding the extent to which age needs to influence employer decisions for the employer to violate the ADEA. A 2009 Supreme Court decision made a distinction between the ADEA’s prohibition against age discrimination and federal law prohibiting so-called status-based discrimination based on race, color, religion, sex, or national origin (Title VII of the Civil Rights Act of 1964). Title VII finds an employer culpable for employment practices for which race, color, religion, sex, or national origin is “a motivating factor,” even if other factors also motivated the practice.
When an employee claiming age discrimination tried to use the “motivating factor” standard for the court’s decision, the Supreme Court disagreed that the standard was appropriate for age discrimination, instead turning to the language in the age discrimination law specifically, which states, “It shall be unlawful for an employer . . . to fail or refuse to hire or to discharge any individual or otherwise discriminate against any individual with respect to his compensation, terms, conditions, or privileges of employment, because of such individual’s age.” The Supreme Court found that the “because of” language brought the issue back to a term familiar in the legal realm, “but-for” causation — the idea that “but for” discrimination against the person’s age, the employer’s action would not have occurred. As applied in that way, the standard requires an employee to show that employer’s action (such as hiring and firing decisions) would not have occurred in the absence of age discrimination. That standard is harder to prove than proving that age discrimination was one of possibly other motivating factors.
Although the case itself and case law that followed emphasized that the decision reflected a distinction between the age discrimination law and discrimination for other reasons (such as race and religion), the reasoning behind the case has begun to seep into case law about other forms of discrimination. A 2013 case held that similar to the 2009 decision on age discrimination, a civil rights claim of unlawful employer retaliation for status-based discrimination requires proof that the desire to retaliate was the but-for cause of the challenged employment action (Univ. of Tex. Southwestern Med. Ctr. v. Nassar, 133 S.Ct. 978 (2013)).