Psychologist Woo-kyoung Ahn explains why our judgement is so often wrong—and offers strategies to help us respond to the challenges we all face as individuals and in society at large. What can K-pop dance moves teach us about how we can best learn new skills? How can a winning soccer goal illustrate the challenge of assigning credit or blame? Why should we think about the way we shop for holiday gifts before starting a new project? Professor Woo-kyoung Ahn devised a course at Yale called “Thinking” to help students examine the biases that cause so many problems in their daily lives. It quickly became one of the college’s most popular courses. Now, for the first time, she presents key insights from her years of teaching and research in a book for everyone. Ahn shows how ‘thinking problems’ stand behind a wide-range of challenges from common, self-inflicted daily aggravations to our most pressing societal issues and inequities. Throughout, Ahn draws on decades of research from other cognitive psychologists, as well as from her own ground-breaking studies. And she presents it all in a compellingly readable style using fun examples from pop culture, anecdotes from her own life, and illuminating stories from history and the headlines. Thinking 101 is a book that goes far beyond other books on thinking, showing how we can improve not just our own daily lives through better awareness of our biases, but the lives of everyone around us. It is, quite simply, required reading for everyone who wants to think—and live—better.