Morgan Freeman has given many powerful, memorable performances. His role as Mr. Clark, a New Jersey-based high school principal known for dispensing authoritarian discipline in “Lean on Me,” is certainly memorable, but that depiction and many others of Black male teachers are based on prejudiced tropes about Black families that were generated from 20th-century social science research — a form of racial knowledge that reified an anti-Black epistemic order of knowledge, according to a new study published by Daniel Thomas III of the University of Kansas.