In a series of illuminating, often surprising experiments, MIT behavioral economist Dan Ariely refutes the common assumption that we behave in fundamentally rational ways. Blending everyday experience with groundbreaking research, Ariely explains how expectations, emotions, social norms, and other invisible, seemingly illogical forces skew our reasoning abilities.

Not only do we make astonishingly simple mistakes every day, but we make the same types of mistakes, Ariely discovers. We consistently overpay, underestimate, and procrastinate. We fail to understand the profound effects of our emotions on what we want, and we overvalue what we already own. Yet these misguided behaviors are neither random nor senseless. They're systematic and predictable—making us predictably irrational.

From drinking coffee to losing weight, from buying a car to choosing a romantic partner, Ariely explains how to break through these systematic patterns of thought to make better decisions. Predictably Irrational will change the way we interact with the world--one small decision at a time.