Over the last forty years, the concept of immutability has been central to Equal Protection doctrine. According to current doctrine, a trait is immutable if it is beyond the power of an individual to change or if it is fundamental to personal identity. A trait that meets either of these criteria receives heightened legal protection under constitutional antidiscrimination law. Yet most legal scholars who have addressed the topic have called for the abandonment of the immutability criterion on the grounds that the immutability criterion is conceptually confused, morally indefensible, and bound to stigmatize subordinate groups. A rejection of the immutability criterion is unwarranted. The immutability criterion must be understood as targeting ...