Of the many obstacles to racial justice in America, none has received more recent attention than the one that lurks in our subconscious. As social movements and policing scandals have shown how far from being "postracial" we are, the concept of implicit bias has taken center stage in national conversation about race. Millions of Americans have taken online tests purporting to show the deep, invisible roots of their prejudice. When a recent Oxford study claimed to have found a drug that reduced implicit bias, it was only the starkest example of a pervasive trend. But what do we risk when we seek the simplicity of a technological diagnosis-and solution-for racism? What do we miss when we locate racism in our biology and our brains rather than in our history and our social practices? In Race on the Brain, Jonathan Kahn argues that implicit bias has grown into a master narrative of race relations-one with profound if unintended negative consequences for law, science, and society. He emphasizes its limitations, arguing that while useful as a tool to understand particular types of behavior, it is only one among the various tools available to policymakers. An uncritical embrace of implicit bias, to the exclusion of power relations and structural racism, undermines civic responsibility for addressing the problem by turning it over to experts. Technological interventions, including many tests for implicit bias, are premised on a color-blind ideal and run the risk of erasing history, denying present reality, and obscuring accountability.