Racial hoaxes reinforce different groups’ worst suspicion of one another: Whites are racists. Blacks are criminals. Over the past 25 years, I’ve analyzed more than 100 racial-hoax cases, beginning with the 1987 case of Tawana Brawley, an African American teen who falsely said that several white men had raped her. A woman has been charged with vandalism under $1,000 after authorities say she used a rock to carve “white pride” into the sidewalk at a Johnson City business. Black people who create hoaxes are more likely to say they were victims of a hate crime by an imaginary white perpetrator....