Thinking, Fast and Slow

Thinking, Fast and Slow is a 2011 popular science book by the Israeli-American psychologist Daniel Kahneman. Its main thesis is a differentiation between two modes of thought: "System 1" is fast, instinctive and emotional; "System 2" is slower, more deliberative, and more logical. The book delineates rational and non-rational motivations or triggers associated with each type of thinking process, and how they complement each other, starting with Kahneman's own research on loss aversion. From framing choices to people's tendency to replace a difficult question with one that is easy to answer, the book summarizes several decades of research to suggest that people have too much confidence in human judgement. Kahneman performed his own research, often in collaboration with the psychologist Amos Tversky, which enriched his experience to write the book. It covers different phases of his career: his early work concerning cognitive biases, his work on prospect theory and happiness, and with the Israel Defense Forces. Jason Zweig, a columnist at The Wall Street Journal, helped write and research the book over two years. The book was a New York Times bestseller and was the 2012 winner of the American National Academies Communication Award for best creative work that helps the public understanding of topics in behavioral science, engineering and medicine. The integrity of some priming studies cited in the book has been called into question in the midst of the psychological replication crisis.