Why do smart people make irrational decisions every day? The answers will surprise you. Predictably Irrational is an intriguing, witty and utterly original look at why we all make illogical decisions.

Why can a 50p aspirin do what a 5p aspirin can't? If an item is "free" it must be a bargain, right? Why is everything relative, even when it shouldn't be? How do our expectations influence our actual opinions and decisions?

In this astounding book, behavioural economist Dan Ariely cuts to the heart of our strange behaviour, demonstrating how irrationality often supplants rational thought and that the reason for this is embedded in the very structure of our minds.

Predictably Irrational brilliantly blends everyday experiences with a series of illuminating and often surprising experiments, which will change your understanding of human behaviour. And, by recognizing these patterns, Ariely shows that we can make better decisions in business, in matters of collective welfare, and in our everyday lives, from drinking coffee to losing weight, from buying a car to choosing a romantic partner.