A provocative and eye-opening history of how we have studied and theorized social interaction.   In this ambitious, wide-ranging book, anthropologist Michael Lempert offers a conceptual history that explores how, why, and with what effects we have come to think of interactions as “scaled.” Focusing on the sciences of interaction in midcentury America, Lempert traces how they harnessed diverse tools and media technologies, from dictation machines to 16mm film, to study communication “microscopically.” In looking closely, many hoped to transform interaction: to improve efficiency, grow democracy, curb racism, and much else. Yet their descent into a microworld created troubles, with some critics charging that these scientists couldn’t see the proverbial forest for the trees. Exploring talk therapy and group dynamics studies, social psychology and management science, conversation analysis, “micropolitics,” and more, Lempert shows how scale became a defining problem across the behavioral sciences.   Ultimately, he argues, if we learn how our objects of study have been scaled in advance, we can better understand how we think and interact with them—and with each other—across disciplinary and ideological divides. Even as once-fierce debates over micro and macro have largely subsided, Lempert shows how scale lives on and continues to affect the ethics and politics of language and communication today.