Intelligent, lively, and thoroughly engaging, a companion volume to Freakonomics and Blink that explains why we often make bad decisions—and what we can do about it. Why does headache pain persist after taking a one-cent aspirin, but disappear after ingesting a pill that costs 50 times that amount? Why does recalling the Ten Commandments reduce our tendency to lie, and honor codes effectively reduce dishonesty at the workplace? Why, after careful and extensive research on a a particular car model, a random meeting with someone who expressed a negative opinion change the decision to buy? Why do we make decisions contrary to our better judgment? And what exactly is “better judgment?” In this astounding new book, groundbreaking in scope and thoroughly original, behavioral economist Dan Ariely cuts to the heart of our strange behavior. In Predicatally Irrational he demonstrates how irrationality often supplants rational thought—especially when we most “need to be levelheaded”—and explains why. As research shows, the behaviors that skew our judgments are neither random nor senseless. In fact, our irrationality is systematic. People repeatedly make the same types of mistakes in a predictable manner because the behaviors have structural origins. Ariely helps us to recognize and understand these structual patterns and offers a way to break through them. With Predictably Irrational, readers will gain new insight into human nature that will help them make better decisions, improve their lives, and ultimately benefit us all.