Historically, the psychology of ignorance has been under-explored, despite being a topic of great importance to anyone wishing to understand human behaviour. In this volume, Smithson develops foundations for a psychology of ignorance by providing an extensive and critical account of what psychology has to say about ignorance. The book's scope includes the nature and causes of ignorance, when and why we attribute ignorance to ourselves or to others, how we feel, think, and behave when we are aware of our ignorance, when and why we choose to be ignorant, and how and why we impose ignorance on one another. Its primary goals are making psychology's implicit treatments of ignorance explicit, identifying missing connections within psychology on this topic as well as connections with other disciplines, and rebalancing psychology's largely negative orientation towards ignorance. As well as focusing on the nature of ignorance and its neglect as a research topic by psychology, the book examines varieties of dysfunctional ignorance and their relations with psychological disorders, investigates decision making under various kinds of ignorance and uncertainty, and explores how and why we create and impose ignorance on each other through indirection, secrecy, lies, and censoring.