A pioneer of social psychology, Claude M. Steele is renowned for Whistling Vivaldi, a bestseller that analysed societal stereotypes—from beliefs about racial and gender test score gaps to the athletic prowess of Black men—and how to mitigate them. In Churn, he coins a new term to identify “the agitation we can feel in diverse settings”, such as everyday exchanges between teachers and students; police and the public; managers and employees; parents and children; and strangers, or even friends, of different sexes and races. Steele braids together psychological research with his own biracial life story, demonstrating how initial wariness between people of different identities is as much a product of our history as of our biases. Through brilliant analysis Churn reveals how trust building can be a fresh and powerful strategy for mitigating these tensions in the real-life settings of our lives and for realising the full potential of a multiracial, multiethnic and multi-classed democracy.