A century ago, everyone knew that people were fated by their race, sex, and nationality to be more or less intelligent, nurturing, or warlike. But Columbia University professor Franz Boas looked at the data and found that racial categories were biological fictions. In this National Book Critics Circle Award finalist, Charles King profiles Boas's contributions to cultural anthropology through his best-known students: Margaret Mead, the outspoken field researcher; Ella Deloria, the Dakota Sioux activist; and Zora Neale Hurston, whose studies informed her classic novel, Their Eyes Were Watching God.