Predictably Irrational, Revised and Expanded Edition: The Hidden Forces That Shape Our Decisions

“This is a wonderful, eye-opening book. Deep, readable, and providing refreshing evidence that there are domains and situations in which material incentives work in unexpected ways. We humans are humans, with qualities that can be destroyed by the introduction of economic gains. A must read!” (Nassim Nicholas Taleb, New York Times bestselling author of The Black Swan: The Impact of the Highly Improbable)

“Sly and lucid. . . . Predictably Irrational is a far more revolutionary book than its unthreatening manner lets on.” (New York Times Book Review)

“Surprisingly entertaining. . . . Easy to read. . . . Ariely’s book makes economics and the strange happenings of the human mind fun.” (USA Today)

“A fascinating romp through the science of decision-making that unmasks the ways that emotions, social norms, expectations, and context lead us astray.” (Time magazine)

“In creative ways, author Dan Ariely puts rationality to the test. . . . New experiments and optimistic ideas tumble out of him, like water from a fountain.” (Boston Globe)

“An entertaining tour of the many ways people act against their best interests, drawing on Ariely’s own ingeniously designed experiments. . . . Personal and accessible.” (BusinessWeek)

“Ariely’s book addresses some weighty issues . . . with an unexpected dash of humor.” (Entertainment Weekly)

“Inventive. . . . An accessible account. . . . Ariely is a more than capable storyteller . . . If only more researchers could write like this, the world would be a better place.” (Financial Times)

“Ariely’s intelligent, exuberant style and thought-provoking arguments make for a fascinating, eye-opening read.” (Publishers Weekly)

“A taxonomy of financial folly.” (The New Yorker)

Why do our headaches persist after we take a one-cent aspirin but disappear when we take a fifty-cent aspirin?

Why do we splurge on a lavish meal but cut coupons to save twenty-five cents on a can of soup?

When it comes to making decisions in our lives, we think we're making smart, rational choices. But are we?

In this newly revised and expanded edition of the groundbreaking New York Times bestseller, Dan Ariely refutes the common assumption that we behave in fundamentally rational ways. From drinking coffee to losing weight, from buying a car to choosing a romantic partner, we consistently overpay, underestimate, and procrastinate. Yet these misguided behaviors are neither random nor senseless. They're systematic and predictable—making us predictably irrational.