High Court’s Default Test for Proving Job Bias Remains Murky

The U.S. Supreme Court recently handed down a pair of rulings that cemented its view on the default standard for proving workplace bias, but legal scholars say some confusion remains about what that test requires and how difficult it is for workers to meet.

The high court has said workers must show that they wouldn’t have been fired or suffered some other adverse employment action except for their employer’s bias, unless Congress included specific language in a statute that justifies applying a different standard.

That test—known as “but-for causation”—represents a higher bar than the standard favored by worker advocates and ...